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Question 1

Pseudoexfoliation (PXF) Syndrome

Answer 1

Risk Factors
• Female sex
• Increasing age
• Polymorphisms in LOXL1
(lysyl oxidase-like1) gene

Examination
• Whitish dandruff-like material on pupillary border and anterior lens capsule (centrally and peripherally with clear intermediate zone)

• Peripupillary transillumination defects
• Poor mydriasis
• Iridodonesis/phacodonesis

• Cataract: nuclear, PSC
• Check IOP
• Perform gonioscopy
– Open angle
– Closed angle from weak zonules with anterior movement of lens-iris diaphragm
– Increased but irregular TM pigmentation
– Flecks of PXF material
– Sampaolesi’s line — pigmented line anterior to Schwalbe’s line

• Examine the optic nerves to look for signs of glaucoma:
– Generalised signs: CDR 0.7 or more, asymmetry of CDR of 0.2 or more, progressive enlargement of cup
or – Focal signs: rim thinning/notching (ISNT rule), regional pallor, NFL haemorrhage, NFL loss

Useful information about PXF syndrome
• A systemic condition in which white dandruff like material is deposited over the anterior segment of the eye and other organs such as the heart, skin, lungs, kidneys

Locating Schwalbe’s line on gonioscopy

Finding Schwalbe’s line on gonioscopy: dark room, short narrow slit beam at oblique angle, identified by the corneal wedge that is created at the junction between the inner light beam along the corneal endothelium and the outer light beam along the corneoscleral junction

Investigations
• HVF
– Early: paracentral defect, nasal step — IT or ST rim thinning, temporal wedge — nasal disc thinning
– Late: arcuate defect, double arcuate defect, central vision only
– Ensure VF defects correlate with optic
nerve head findings

Treatment
• If raised IOP: medical, SLT, trabeculectomy (higher complication rate but similar overall success to trabeculectomy in POAG)

• Cataract extraction if IOP controlled: weak zonules (CTR), small pupil
(I/C phenylephrine, Iris hooks)

Prognosis
• Compared to POAG, the disease course is more severe, with poorer response to medical therapy and more frequent need for surgery
• Glaucoma risk: 1% at 1 year, 5% at 5 years, 15% at 15 years

Question 2

Pigment Dispersion Syndrome (PDS)

Answer 2

Risk Factors for PDS

• Myopia
• Age 20–40
• Male sex
• Caucasian ethnicity

Risk Factors for Conversion of PDS to Pigmentary
Glaucoma
• Male gender
• Black race
• Higher degrees of myopia
• Krukenberg spindles

Useful information about PDS
• A condition characterised by the release of pigment from the mid-peripheral posterior surface of the iris, from where it is distributed around the anterior segment
• Pigment release is thought to occur as a result of posterior bowing of the mid peripheral iris rubbing against the zonules
• Reverse pupillary block: AC pressure greater than PC pressure (pushing peripheral iris backwards against the lens zonules)

Examination
• Krukenberg spindle: pigment on the endothelium in a vertical line
• Mid-peripheral spoke like iris transillumination defects
• Scheie strip: pigment deposit along the insertion of the zonular fibers to the anterior lens capsule
• Check IOP
• Perform gonioscopy
– Open angle
– 360° of homogenous pigmentation of TM

– Sampaolesi’s line
– Posterior bowing of the iris
– Dilated fundus exam:
Look at optic disc for signs of glaucoma:
• Generalised signs: CDR 0.7 or more, asymmetry of CDR of 0.2 or more,
progressive enlargement of cup
• Focal signs: rim thinning/notching — ISNT rule, regional pallor, NFL haem-
orrhage, NFL loss
Look at the peripheral retinal for lattice degeneration
Investigations
• HVF
– Early: paracentral defect, nasal step (IT or ST rim thinning), temporal wedge (nasal
disc thinning)
– Late: arcuate defect, double arcuate defect,central vision only

Treatment
• If IOP raised – Medical
– SLT: good response initially — less effective in patients who are older and who have had glaucoma for a longer period of time — use lower initial power settings to reduce post laser IOP spike
– Trabeculectomy: increased risk of postop hypotonus maculopathy
• With increasing age, there is an apparent improvement or at least an arrest in the disease process — postulated to result from an increasing AL of the lens over time, which lifts the peripheral iris off the lens zonules, preventing the rubbing between iris and zonules and the subsequent release of pigment granules

Role of PI in PDS/Pigmentary Glaucoma
• Insufficient evidence of high quality on the effectiveness of PI for pigmentary glaucoma or PDS

Other Diagnoses to Consider
• Trauma: surgical (pigment dispersion with PCIOL — rubbing of lens haptic and optic against posterior iris — transillumination defects corresponding to position of lens haptic and edges of optic) and non-surgical (angle-recession)
• Uveitis: photophobia, KP’s, cells/flare, PS, gonioscopy (PAS, increased TM pigmentation but is seen as irregular clumps of pigment randomly dispersed, usually in the inferior quadrants/widened ciliary body band in angle recession)
• POAG with increased pigmentation: TM pigmentation tends to be more segmental, patients typically older

Question 3

Neovascular Glaucoma (NVG)

Answer 3

Causes of NVG
• Retinal ischaemic diseases: Ischaemic CRVO (50% risk of conversion to NVG), DR, OIS, chronic RD, BRVO, CRAO, SCR
• Inflammatory diseases: Uveitis
• Tumours: iris (melanoma), retinal or
choroidal
Examination
• Iris rubeosis: small, fine tortuous vessels at the pupillary margin, mid and peripheral anterior surface of the iris
• Ectropion uvea
• Check the IOP
• Perform gonioscopy
– Look for NVA— vessels on the TM and ciliary body band
– Open angle or closed angle with PAS (typically ends at Schwalbe’s line)
• Examine the optic nerve for signs of glaucoma:
– Generalised signs: CDR 0.7 or more, asym- metry of CDR of 0.2 or more, progressive enlargement of cup

– Focal signs: rim thinning/notching (ISNT rule), regional pallor, NFL haemorrhage, NFL loss)
• Dilated fundus examination to look for any underlying retinal ischaemic diseases
Investigations
• Carotid doppler US: if no retinal pathology or asymmetric DR (rule out OIS)
• B-scan US: if poor/no fundal view from dense cataract (tumours, RD)
• HVF: early: paracentral defect, nasal step — IT or ST rim thinning, temporal wedge — nasal disc thinning / late: arcuate defect, double arcuate defect, central vision only
Treatment
• Treat underlying cause: RD repair for RD, carotid endarterectomy for OIS
• Neovascularisation: PRP ± anti-VEGF injection
• IOP control: reduction of raised IOP with medical treatment and surgical treatment if medical treatment fails (GDI, trabeculectomy, cyclodiode — visual potential of eye will determine best surgical option for patient)
• Pain control: reduction of IOP if raised, cycloplegia, topical steroids, if vision poor and eye phthisical — retrobulbar alcohol, evisceration/enucleation

Question 4

Primary Congenital Glaucoma (PCG)

Answer 4

Examination
• Enlargement of globe/cornea if onset less than age 4 years: Buphthalmos

• Dense corneal stromal opacification

• Curvilinear lines in Descemet’s membrane(from stretching of the cornea):
Haab striae

• Measure the corneal diameter (more than 13 mm)

• Check IOP

• Perform gonioscopy: high iris insertion, indistinct angle landmarks, fine iris processes

• Examine the optic disc for signs of glaucoma

– Generalised signs: CDR 0.7 or more, asymmetry of CDR of 0.2 or more, progressive enlargement of cup

– Focal signs: rim thinning/notching (ISNT rule), regional pallor, NFL haemorrhage, NFL loss

Investigations
• HVF: early: paracentral defect, nasal step (IT or ST rim thinning), temporal wedge (nasal disc thinning) / late: arcuate defect, double arcuate defect, central vision only

Treatment
• If IOP raised/glaucoma
– Medical treatment to lower IOP acutely
– Surgical treatment options:
Goniotomy
Trabeculotomy
Trabeculectomy
GDI
Cyclodiode
Corneal opacification – PK

Useful information about PCG
• Angle dysgenesis causes reduced aqueous outflow
• Typically diagnosed within first year of life but not usually at birth
• 2% chance of affected parent having affected child if no FHx of PCG
• Bilateral in 70% and more common in males
• PCG (CYP1B1 gene): first 3 years of age
• Primary juvenile glaucoma (MYOC gene):
4–16 years of age

Question 5

Aphakic Glaucoma

Answer 5

Causes of Aphakia
• Removal of congenital cataracts without subsequent IOL implantation
• Complicated cataract surgery without IOL implantation
• Dislocated lens: trauma or connective tissue disorders
• Previous ICCE with spectacle rehabilitation
• Primary congenital aphakia

Mechanism of IOP Elevation in Aphakia
• Distortion of AC angle
• PAS: flat AC post-op, inflammation
• Pigment dispersion post cataract surgery

• Pupil block (post ICCE): adherence between the iris and anterior vitreous face after a transient flat AC secondary to a wound leak

Complications of Aphakia
• Glaucoma
• Retinal detachment (RD): vitreous traction on retina (complicated surgery)

Examination
• Aphakic
• Check IOP
• Perform gonioscopy: open angle, PAS
• Examine the optic disc for signs of glaucoma
– Generalised signs: CDR 0.7 or more, asym- metry of CDR of 0.2 or more, progressive enlargement of cup
– Focal signs: rim thinning/notching (ISNT rule), regional pallor, NFL haemorrhage, NFL loss
• Perform a dilated fundus examination to look for a RD
Investigations
• HVF: early: paracentral defect, nasal step (IT or ST rim thinning), temporal wedge (nasal disc thinning)/late: arcuate defect, double arcuate defect, central vision only
Treatment

• Medical
• Surgical options
– GDI’s (initial surgical intervention) – Trabeculectomy

Question 6

Sturge-Weber Syndrome (Encephalotrigeminal
Angiomatosis)

Answer 6

Examination
• Naevus flammeus of the face (port-wine stain) along distribution of CN V
• Dilated and tortuous episcleral and conjunctival vessels
• Check IOP
• Perform gonioscopy: open angle or lack of anatomical landmarks
• Examine the optic disc for signs of
glaucoma
– Generalised signs: CDR 0.7 or more, asymmetry of CDR of 0.2 or more, progressive enlargement of cup
– Focal signs: rim thinning/notching (ISNT
rule), regional pallor, NFL haemorrhage,
NFL loss
• Perform a dilated fundus examination to look for a diffuse (tomato ketchup red appearing fundus) or circumscribed choroidal haemangioma
Investigations
• HVF: early: paracentral defect, nasal step (IT or ST rim thinning), temporal wedge (nasal disc thinning)/late: arcuate defect, double arcuate defect, central vision only
• MRI head: look for CNS haemangiomas

Treatment
• If IOP high
– Medical treatment: topical medications
– Surgical treatment if medical treatment
fails:

Trabeculotomy
Goniotomy
Trabeculectomy (associated with intraop- erative choroidal effusion ± expulsive haemorrhage) with prior prophylactic posterior sclerostomies
GDI
Cyclodiode
• Treat choroidal haemangiomas if associated with a secondary exudative RD: options include PDT or external beam radiotherapy
• Cosmetic appearance of the naevus flammeus of the face can be improved by laser photocoagulation in infancy or late cosmetics to cover the defect

Key facts about Sturge-Weber syndrome
• Type of phakomatosis (group of disorders characterised by hamartomas: congenital tumours arising from tissue that is normally found in the involved area) that occurs sporadically (no inheritance pattern)
• No race or sex predilection
• Tumours are present at birth
• Mechanism of glaucoma: developmental anomaly AC angle before the first decade of life, elevated episcleral venous pressure after the first decade of life

Question 7

Congenital Aniridia

Answer 7

History
• Positive family history of aniridia (AD inheritance)
• Always ask about family history as if case is sporadic there is a risk of WAGR syndrome (Wilms tumour — nephroblastoma, aniridia, GU abnormalities, reduced IQ)

Examination
• Nystagmus
• Corneal opacification with subepithelial fibrosis and peripheral pannus — LESC deficiency
• Iris hypoplasia (rudimentary iris stump)
• Cataracts
• Check IOP

• Examine optic nerve
– Look for optic nerve hypoplasia
– Look for signs of glaucoma:
Generalised signs: CDR 0.7 or more, asymmetry of CDR of 0.2 or more, progressive enlargement of cup
Focal signs: rim thinning/notching (ISNT rule), regional pallor, NFL haemorrhage, NFL loss
• Perform gonioscopy to look for chronic angle closure caused by blockage of TM by rudimentary iris stump rotating forward
Investigations
• OCT: foveal hypoplasia
• Renal US: nephroblastoma
• HVF: early: paracentral defect, nasal step —
IT or ST rim thinning, temporal wedge — nasal disc thinning/late: arcuate defect, double arcuate defect, central vision only
Treatment
• If IOP raised/glaucoma: topical medication, goniotomy (if clear cornea), trabeculotomy (if cornea cloudy), trabeculectomy — usually first surgical procedure in cases of aniridic glaucoma refractory to medical treatment, GDI’s, cyclodiode in cases refractory to trabeculectomy or GDI

• Keratopathy: Scleral CL, keratolimbal allograft (KLAL), Boston keratoprosthesis (KPro) for severe aniridia associated keratopathy
• Dry eye: lubricants, ointments, punctal occlusion
• Cataract extraction for visually significant cata- racts — beware of fragile anterior capsule
• If patient has significant glare or photophobia (from iris atrophy, polycoria, corectopia): painted or tinted CL
Other Diagnoses to Consider
• Trauma: post-surgical or non-surgical
• Rieger syndrome (see Sect. 9.8)
• ICE syndrome (findings are unilateral)
– Essential iris atrophy: corectopia, iris atro- phy with polycoria (iris hole formation), guttata (fine hammered silver appearance) ± corneal oedema, ectropion uveae, goni- oscopy shows broad based PAS extending to and beyond Schwalbe line
– Cogan-Reese syndrome: unilateral multiple diffuse brown nodules on anterior surface of iris, guttata (fine hammered silver appear- ance) ± corneal oedema, ectropion uveae, iridocorneal adhesions, pupil distortion ± corectopia, gonioscopy shows broad based PAS extending to and beyond Schwalbe line
• Gillespie syndrome: AR, ataxia

Useful information about congenital aniridia
• Congenital aniridia is a bilateral disease with complete or partial absence of iris as well as other ocular abnormalities
• AD with variable expressivity in two-thirds and sporadic in one-third
• Caused by mutations in PAX6 gene

Question 8

Rieger Syndrome

Answer 8

• Anterior segment dysgenesis (failure of the normal development of the anterior segment of the eye)
History
• Positive family history (AD)
Examination
• Findings tend to be bilateral
• Posterior embryotoxin

• Iris atrophy/iris hypoplasia
• Corectopia
• Polycoria (multiple holes in the iris)
• Visible pupil sphincter against the hypoplastic iris stroma
• Check IOP
• Perform gonioscopy: prominent Schwalbe line, iris strands bridging the AC angle from the peripheral iris to the prominent ridge
• Examine the optic disc for signs of
glaucoma
• Systemic examination to look for redundant periumbilical skin, microdontia, oligodontia
Investigations
• HVF: early: paracentral defect, nasal step — IT or ST rim thinning, temporal wedge — nasal disc thinning/late: arcuate defect, double arcuate defect, central vision only
Treatment
• If IOP raised/glaucoma: medical, surgical — goniotomy, trabeculotomy, trabeculectomy, GDI, cyclodiode

• If patient has significant glare or photophobia (from iris atrophy, polycoria, corectopia): painted or tinted CL
Other Diagnoses to Consider
• ICE syndrome: unilateral, guttata, lack of sys- temic abnormalities, manifestation in middle age, female predominance
• Peters anomaly: central corneal opacity with absence of DM and endothelium, iridocorneal adhesions

Question 9

Trabeculectomy

Answer 9

Indications
• Failure to control IOP with MTMT
• Patient intolerant of topical medications
• Patient wishes to be drop free

• First line treatment if patient has advanced disease and needs lower IOP’s or if patient is at high risk of progression

Description of Bleb Morphology
• Area
– Diffuse: thin-walled blebs with large surface area and low elevation
– Flat: blebs showing no important signs of bleb development such as elevation or
microcysts

• Vascularity
– Avascular
– Similar to adjacent conjunctiva
– Increased
– Massive

• Corkscrew vessels
– None
– In one third
– In two thirds
– Entire bleb

• Microcysts
– None
– Over the scleral flap
– Lateral or medial aspect of the scleral flap
– Entire bleb

• Encapsulation (thick-walled blebs with cystic appearance, high elevation and a well demarcated area —)
– None
– In one-third
– In two-thirds
– Entire bleb

Complications and its treatment

• Intraoperative: tearing or buttonholing of the conjunctival flap, haemorrhage (episcleral, choroidal), choroidal effusion, vitreous loss, lens injury, tearing of scleral flap from its limbal hinge

• Early postoperative
– Hypotony (IOP <6 mmHg) and flat/shallow AC
Conjunctival defect/leak (flat bleb) —
pressure patching (check leak again in 1–2 h post patching), temporarily tapering topical steroids, BCL, cyanoacrylate tissue adhesive or autologous fibrin glue, injection of autologous blood inside or around a bleb, surgical re-suturing

Excessive filtration (extensive bleb) — decreasing the frequency of
postoperative topical steroids, reform AC with viscoelastic, resuturing of scleral flap if choroidal detachments present with maculopathy

Ciliary body shutdown (flat bleb) — reform AC with viscoelastic, treat excessive inflammation with topical steroids

– Elevated IOP and flat/shallow AC

Suprachoroidal haemorrhage — surgical drainage (anterior sclerostomies 7–10 days post haemorrhage to enable clot to liquefy) indicated if RD and 360° suprachoroidal haemorrhage, kissing choroidal detachments, vitreous incarceration, vitreoretinal adhesions

Malignant glaucoma (shallow central and peripheral AC) — atropine, disruption of anterior hyaloid face with Yag Laser or vitrectomy

Incomplete iridectomy with pupil block — perform new Yag PI followed by topical steroids and atropine

– Elevated IOP and deep AC:

Inadequate filtration (tight scleral flap or obstruction of fistula by iris,
ciliary processes, lens, blood, or vitreous): laser suture lysis or release of suture, Yag laser to remove obstructing iris or ciliary processes from ostium, revision of filter

– Loss of vision (“wipe out”) — risk factors include older age, preoperative macular splitting in the VF, hypotony

– Bleb-related infections — blebitis (milky bleb — ): intensive topical antibiotics and systemic antibiotics (ciprofloxacin 750 mg BD) / bleb-related endo-phthalmitis (BRE): intravitreal tap + injection of antibiotics, systemic antibiotics (ciprofloxacin 750 mg BD)

• Late postoperative

– Late filtration failure — bleb encapsulation
(highly elevated, smooth dome-shaped bleb with large vessels but intervening avascular spaces and no microcysts): resume topical medications, digital pressure, bleb needling + 5-FU
– Leaking bleb (risk factors: blebs with large avascular area) — aqueous suppressants, BCL, cyanoacrylate glue or autologous fibrin glue, autologous blood, bleb revision surgery

– Bleb-related infections
– Loss of vision — cataract
– Eyelid changes — upper eyelid retraction
(adrenergic effect of aqueous humour on Muller muscle), ptosis (trauma to levator)

Useful information about trabeculectomies
• A filtering surgical procedure that creates an opening, or fistula, at the limbus, which allows a direct communication between the AC and subconjunctival space, with the subsequent formation of a filtering bleb (elevation of conjunctiva at the surgical site)
• Fistula bypasses the TM, Schlemm canal, and collecting channels

Question 10

Glaucoma Drainage Implants (GDI’s)

Answer 10

Types of GDI
Glaucoma Drainage Implants (GDI’s)
• Valved: Ahmed implant
• Non-valved: Baerveldt implant, Molteno
implant

Mechanism of action
• Fibrous capsule forms (after 6–8 weeks) a fil- tering bleb around the external portion of the draining device
Indications
• Classically performed for conditions where a filtering surgery would have a high likelihood of failure
– Conjunctival scarring (from previous VR
surgeries or glaucoma from chemical
burns)
– Uveitic glaucoma
– Neovascular glaucoma
– Aphakic glaucoma
– Angle recession glaucoma
– Childhood glaucomas (e.g. Sturge Weber
syndrome)
– Previous failed trabeculectomy
Complications and its treatment
• Intraoperative
– avulsion of rectus muscles: resuture mus-
cles to insertion sites
– globe perforation while suturing the plate
to the sclera: repair globe
• Post-operative
– Hypotony with flat AC: injection of dense viscoelastic into AC, removal of tube from AC with subsequent repositioning of tube, permanent ligation of tube
– Elevated IOP: medical tx initially, if encapsulated drainage implant from thick fibrous capsule — needling beneath con- junctiva required
– Tube migration, implant extrusion, and erosion of silicone tube through the overly- ing conjunctiva
– Endophthalmitis: removal of GDI, intravit- real tap and injection of antibiotics
– Visual loss

– Corneal decompensation: tube-cornea touch
– Diplopia: acquired Brown syndrome, SO palsy

Useful information about GDIs
• Basic design: silicone tube that extends from the AC to a plate, disc, or encircling element beneath the conjunctiva and Tenon capsule
• Successful outcome of a GDI is most dependent on size of the plate

Question 11

Minimally Invasive Glaucoma Surgery (MIGS)

Answer 11

Types of MIGS and Their
Mechanisms of Action

• Increasing trabecular outflow by bypassing the TM, e.g.

iStent,
Hydrus micro-stent

• Increasing uveoscleral outflow via suprachoroidal pathways, e.g.
CyPass micro-stent

• Creating a subconjunctival drainage pathway, e.g.
XEN implant,
InnFocus Microshunt

Indications
• There is currently little robust
high-quality RCT evidence comparing the efficacy and safety of one MIGS technique over another for OAG

• At present there is no guidelines on the use of MIGS in clinical practice

• Possible indications

– Patients with OAG (POAG, PXF
glaucoma, pigmentary glaucoma) that is
manageable with drops but who have poor drop compliance

– Patients with OAG and a clinically significant cataract, as surgery may be performed simultaneously (Phaco-Plus)

Question 12

Lid Examination Sequence

Answer 12

• Introduce

• Sit in front of patient with patient’s eyes at your eye level

• Quick inspection for any obvious ptosis, brow ptosis, frontalis overaction, eyelid scars from previous surgeries, eyelid malpositions (e.g. ectropion’s or entropions), CN VII palsy

• Ask patient to look straight ahead at a distance target and measure the palpebral aperture (PA): distance from the upper lid margin to the lower lid margin (normal range 9–11 mm)

• Shine a penlight at the patient’s eye and measure the marginal reflex distance 1 (MRD1): distance from central corneal light reflex to the upper lid margin (normal range 4–5 mm)

• Ask patient to look down and measure the upper eyelid skin crease height: distance from lid margin to skin crease (normal range 6–8 mm for men and 8–10 mm for women)

• Measure levator function (LF): block action of patient’s brow with your thumb and measure excursion of the upper lid from extreme down-gaze to extreme upgaze (normal range 13–16 mm)

• Check for the presence of any lagophthalmos by asking patient to close their eyes

• Check orbicularis function by asking patient to squeeze their eyes shut without letting you open their eyes

• Hold a pen above the patient’s eye level and check for fatiguability by asking a patient to look up at your pen for at least 30–60 s (ask examiner if they want you to do this in the exam): if fatiguability is present the eyelid will slowly drop as the patient stares at your pen

• Check for lid lag by asking a patient to follow your pen from upgaze to downgaze

• Hold a pen below the patient’s eye level and check for a Cogan’s lid twitch by asking the patient to look down at your pen for 20 s before asking them to look straight ahead: a positive Cogan’s twitch is present if the upper eyelid overshoots following the sudden return of the eye to the primary position

• Ask patient to open and close the mouth and move the jaw around to check for a Marcus- Gunn jaw winking ptosis

• Check ocular motility and pupils

Question 13

Ectropion

Answer 13

Classification

• Lower eyelid

– Involutional :

horizontal lid laxity

– Paralytic:

loss of orbicularis muscle support of the lower eyelid, associated with lower facial paralysis and brow ptosis (CN VII palsy)

– Cicatricial :

shortening of the anterior lamella from trauma or skin changes

• Upper eyelid

– Cicatricial

• There is no upper eyelid equivalent for paralytic or involutional ectropion

Useful information about Ectropion

• Ectropion occurs when the lid margin everts or turns away from the eyeball

• Any type of ectropion may cause tearing as a result of reflex tearing, punctal eversion, or inadequate lacrimal pump

History

• History of trauma or cicatrising skin disease — ichthyosis (anterior lamellar shortening)

• History of previous excision of skin cancer or repair of laceration in the periocular area
(anterior lamellar shortening)
• History of CN VII palsy

Examination

• Location — medial lid, lateral lid,
entire lid, punctal eversion only

• Examine for scarring of the periocular area: indicate previous accidental or surgical trauma as a cause for cicatricial ectropion

• Examine for generalised tightness of the skin: indicates skin shrinkage as a cause for cicatricial ectropion

• Examine for CN VII palsy suggesting paralytic ectropion: facial asymmetry, flattening of nasolabial folds, co-existing brow ptosis, corneal exposure

• Examine for horizontal eyelid laxity: eyelid distraction test (manually pull lower eyelid away from eyeball, the lower lid should not move more than 6 mm off the eyeball), eyelid snap test (pulling lower eyelid inferiorly toward the inferior orbital rim, an eyelid without lower eyelid laxity will spring back into position without a blink)

• Examine for medial canthal tendon laxity: if lateral traction of lower eyelid displaces the punctum to or beyond the limbus, then medial canthal tendon laxity exists

Treatment

• Horizontal lid shortening procedures

– Lateral tarsal strip (LTS): prepare the patient (inject LA), perform a lateral canthotomy, perform a lateral cantholysis, form the strip (splitting the anterior and posterior lamella, cut along inferior margin of tarsus, remove skin and conjunctiva from the strip), shorten the strip, reattach the strip, trim redundant anterior lamella,
close the canthotomy
– Pentagonal wedge resection: choice of procedure for upper eyelid with floppy eyelid syndrome
– Kuhnt-Szymanowski: wedge resection and lower lid blepharoplasty

• Vertical lid shortening procedures

– Medial spindle procedure (excision of a diamond of conjunctiva inferior to the lower puntum and closure with a suture):
procedure for punctal ectropion alone or combined with LTS if lid laxity present (perform medial spindle procedure before eyelid is tightened with a LTS).

• Combined lid shortening procedures
– Lazy T: diamond excision (medial spindle
procedure) and wedge resection

• Involutional ectropion: lid shortening
procedures

• Paralytic ectropion: correction of corneal
exposure with lubricants and ointments, lid shortening procedures

• Cicatricial ectropion: lengthening of anterior lamella with full-thickness skin graft (pre-auricular, post-auricular, supraclavicular area, inner upper arm, inguinal area)

Question 14

Entropion

Answer 14

Classification

• Lower eyelid

– Involutional: disinsertion or laxity of the
lower eyelid retractors (primary cause of involutional entropion as it allows the
inferior edge of the tarsus to rotate away from the eye), horizontal lid laxity, overriding preseptal orbicularis muscle

– Cicatricial: shortening of the posterior lamella (pulls eyelid margin inwards) from scarring of the conjunctiva
(e.g. alkali burns, surgical or accidental
trauma, OCP, SJS, trachoma)

– Spastic: squeezing of the lids in association with ocular pain or inflammation, entropion resolves once discomfort disappears, occurs in patients who have predisposing factors to involutional entropion such as horizontal lid laxity and lax lower lid retractors

– Congenital

• Upper eyelid

– Cicatricial

History
• Intermittent symptoms of irritation: suggest an involutional cause

• Constant symptoms of irritation: suggests a cicatricial cause

• Hx of previous surgical or accidental trauma

• Hx of chemical injuries, OCP, SJS, trachoma

Examination

• For subtle entropions, look for a slightly rolled appearance of the posterior angle of the lid margin (should be a flat platform with well- defined right-angled anterior and posterior edges). For intermittent entropions not seen on examination initially, ask patient to squeeze eyes to elicit entropion

• Examine to determine if entropion is cicatricial: with your finger, return the inverted lid to its normal position. If cicatricial changes are present, there is resistance to placing the lid in the normal position and after you release the lid it will immediately return to its inverted position, examine the conjunctiva for signs of fornix shortening or scarring

• Examine the degree of conjunctival scarring: identify the position of the meibomian gland orifices in the least inverted part and follow to
most inverted part, in severe scarring the meibomian gland openings may be on the posterior surface of tarsus

• If not cicatricial, the entropion must be involutional: lid returns to normal position with your finger and it will remain there for a blink or two. If entropion does not recur with a few blinks, ask the patient to squeeze the lids closed for a moment, lower eyelid may ride above the lower limbus suggesting some laxity of the lower eyelid retractors
• Examine for horizontal lid laxity if involutional entropion present: eyelid distraction test (manually pull lower eyelid away from eyeball, the lower lid should not move more than 6 mm off the eyeball), eyelid snap test (pulling lower eyelid inferiorly toward the inferior orbital rim, an eyelid without lower eyelid laxity will spring back into position without a blink)

Treatment

• Involutional (aim is to restore the normal tension of the lower lid retractors and to correct any co-existing horizontal lid laxity)

– Retractor reinsertion procedure:
Jones procedure — lower lid subciliary incision, identify lower lid retractors (landmark is the preaponeurotic fat), dissect retractors from anterior fat and posterior conjunctiva, advance lower lid retractors onto the tarsus, skin closure

– Horizontal lid shortening procedure:
LTS, wedge excision, Kuhnt-Szymanowski

•Cicatricial
(aim is to restore normal length of the posterior lamella using either incisions alone or incisions with mucous membrane grafts)

– Tarsal fracture (tarsotomy — requires a
contact lens post op for a few weeks to avoid irritation of cut tarsus) if mild-moderate cicatricial changes,

– Terminal tarsal rotation operation for upper eyelid entropion

– Mucous membrane grafts if severe cicatricial changes

• Spastic

– Treat cause of underlying irritation causing spasm

–If not possible to eliminate the cause of irritation:

Quickert sutures: topical and local anaesthetic, load a double armed suture, pass the arms of the suture thought the lid from deep in the fornix passing anteriorly and superiorly to emerge from the skin just below the eyelashes, repeat so that there are medial, central, and lateral sutures in position, tie the sutures so that there is a slight overcorrection

Useful information about entropion

• Lid margin inverts or turns against the eyeball

• Keratinised skin of the eyelid margin and eyelashes rub against the cornea and conjunctiva, causing irritation

Question 15

Facial Nerve (CN VII) Palsy

Answer 15

Causes of CN VII palsy

Facial Nerve (CN VII) Palsy

• Bell’s palsy (diagnosis of exclusion)

• Acoustic neuroma (cerebellopontine angle tumour)

• Facial tumour (parotid gland mass)

• Trauma

• Ramsay-Hunt syndrome (VZV): otalgia,
vesicular rash on ear canal, tympanic
membrane

• Sarcoidosis (CN VII palsy tends to be
bilateral)

• Lyme disease (CN VII palsy tends to be
bilateral)

History

• History of otalgia, hearing loss, or vestibular complaints (if present patient needs scanning)

• Find out likelihood of recovery from ENT colleagues — perhaps tumour resection required cutting the facial nerve, meaning there is no chance of recovery

Examination

• Look for incomplete blink
• Look for brow ptosis
• Look for lower eyelid ectropion
• Look for lagophthalmos with corneal
exposure
• Examine for Bell’s phenomenon: if good,
patients may have little or no corneal exposure despite incomplete closure
• Examine for aberrant regeneration: narrowing of palpebral fissure on pursing of lips/showing of teeth
• Examine corneal sensation: may be reduced if CN VII palsy is due to acoustic neuroma resection (resection may compromise CN V as CN V, VII, VIII leave the brainstem in close proximity) — reduced corneal sensation makes corneal exposure more difficult to manage
Investigations

• ENT referral to establish cause for all new- onset CN VII palsy

• MRI for UMN facial palsy, recurrent CN VII palsy or patients with otalgia, vestibular symptoms, or hearing loss to exclude inflammatory or neoplastic (cerebellopontine angle) causes

Treatment
• Treatment depends on how permanent the palsy is likely to be, the degree of anatomic dysfunction (Bells phenomenon), and the patient’s needs

• Corneal exposure
– Medical treatment:
Hourly artificial tears or ointments Eyeglasses outdoors to protect the eye from the wind
Avoidance of moving air from fans or heating vents indoors
Taping lid closed at night

– Surgical treatment (if corneal exposure cannot be managed medically or the facial paralysis is likely to be long term, e.g. no improvement in 18 months):
Static procedures (narrow the palpebral aperture a fixed amount):
•Tarsorrhaphy: temporary or permanent
• Elevation of lower eyelid (retractor disinsertion ± graft)
Dynamic procedures (improve lid closure):
• Botox:
– Technique: 25G needle passed through central aspect of upper lid immediately inferior to the superior orbital rim, needle passed against orbital roof for 1–2 cm, 5–10 units are injected, after 48 h the upper lid rests closed
– Side-effects: ocular surface dryness (temporary paralysis of orbicularis and decreased blinking), upper eye- lid ptosis and diplopia (botox induced paresis of the levator muscle or extra- ocular muscles) — may last for 6 weeks

• Upper eyelid gold weight implantation

• Ectropion — LTS ± medial spindle procedure

• Brow ptosis — browplasty

• Aberrant regeneration: treat if narrowing of palpebral fissure affects vision. Options
include Botox and levator aponeurosis
advancement

• For Bell’s palsy — oral prednisolone (25 mg BD) for 10 days starting within 72 h after the onset of symptoms has increased complete recovery rates from 64% to 83% at 3 months and from 82% to 94% at 9 months

Surgical technique for a temporary suture tarsorrhaphy
• Can be placed anywhere along the lid margins. The nylon suture can be left in place for 2 weeks
• Topical anaesthetic and inject local anaesthetic into the eyelids
• Cut two 5 mm pieces of a narrow red rubber catheter to use as bolster material
• Pass one arm of a double ended 5/0 nylon suture through the bolster material, then into the lower lid skin 5 mm below the lid margin, emerging out the lid margin through the meibomian glands, into the opposite lid margin, out the skin 5 mm above the upper eyelid margin, and through the second bolster
• Repeat this procedure with the other arm of the suture
• Tie a slip knot over the bolster on the upper eyelid

Question 16

Simple Congenital Ptosis

Answer 16

History

• Present at birth with no associated ocular or systemic problems

• For a child: Is the lid above the pupil? How many times is lid above the pupil?

• History of previous ptosis surgery ± secondary lagophthalmos

• History of CN VII palsy

• History of dry eye/use of topical lubricants

Examination

• Reduced/poor levator function

• Absent or weak upper eyelid crease

• Lid lag on downgaze ± lagophthalmos

• Examine for amblyopia (astigmatism or deprivation) in a child

• Examine for risk factors that would increase the chance of post-operative corneal exposure: poor Bell’s phenomenon,lagophthalmos

• Examine anterior segment for dry eye: assess tear lake height, fluorescein staining of cornea, Schirmer’s I test, TBUT

• Normal ocular motility (or SR weakness alone in 5%) and pupil examination

Treatment

• If levator function <4 mm, a frontalis sling procedure is appropriate

• If levator function ≥4 mm, a levator aponeurosis advancement is appropriate

Question 17

Involutional Ptosis

Answer 17

History

• Indefinite onset

• Gradual progression

• No associated ocular or systemic problems

• Ptosis usually about the same severity throughout the day

• History of previous ptosis surgery ± secondary lagophthalmos

• History of CN VII palsy

• History of dry eye/use of topical lubricants

Examination

• Normal (13–16 mm) or near normal (12 mm) levator function

• High skin crease (8–10 mm in women, 6–8 mm in men)

• Lid drop on downgaze (lid margin remains low throughout downgaze)

• Examine for dermatochalasis or brow ptosis: combined surgery with levator aponeurosis advancement may be required

• Examine for risk factors that would increase the chance of post-operative corneal exposure: poor Bell’s phenomenon, lagophthalmos

• Examine anterior segment for dry eye: assess tear lake height, fluorescein staining of cornea, Schirmer’s I test, TBUT

• Normal ocular motility and pupil examination

Treatment

• Levator aponeurosis advancement procedure ± brow plasty ± blepharoplasty

Question 18

Chronic Progressive External Ophthalmoplegia (CPEO)

Answer 18

History
• Ask about family history to rule out myotonic dystrophy and oculopharyngeal dystrophy

Examination

• Bilateral progressive symmetrical ptosis with poor levator function (CPEO), good levator function initially with oculopharyngeal dystrophy

• CN VII weakness especially orbicularis weakness (CPEO)

• Test fatigability (MG): ask patient to look up for 30–60 s and upper eyelid will fatigue and slowly drop

• Look for Cogan’s eyelid twitch (MG): ask patient to look down for 20 s and then at object in the primary position — positive if lid overshoots

• Progressive symmetrical advanced loss of ocular motility (eyes virtually immobile with secondary fibrotic changes in advanced stages) — reduced pursuits and always reduced (hypometric) saccadic velocities (CPEO), check for improvement in ocular motility with Dolls head testing (Supranuclear gaze palsy), normal saccadic velocities in MG, down and
out eye in complete CN III palsy

• Normal pupil reactions and accommodation(CPEO), mydriasis with poor reactions (CNIII palsy)

• Examine for X-mas tree cataract, frontal balding, slow release grip (myotonic dystrophy)

• Fundus exam: pigmentary retinopathy (Kearns-Sayre syndrome/myotonic dystrophy)

• Ask patient to drink glass of water quickly(oculopharyngeal dystrophy)

Investigations
• ECG (Kearns-Sayre syndrome/myotonic dystrophy): heart conduction defects

• Fields of uniocular fixation (CPEO)

• Tensilon test (MG): ensure IV atropine, resuscitation equipment, and trained staff is on hand, cardiac monitoring (ECG) essential. Give 2 mg edrophonium IV and if no ill effects at 30s, give further 8 mg edrophonium IV. Compare pre- and post-test ptosis or motility disorder

• Ice pack test (MG): measure ptosis, ice cubes in rubber glove with patient holding it over their eyelid for 2 min, re-measure ptosis: positive if ≥2 mm improvement

• Serum antibodies (MG): anti-Ach receptor antibodies (50% ocular myasthenia, 95% generalised myasthenia)

• Single fiber EMG (MG); reduction in action potential amplitude

• Hess chart (CN III palsy)

• Skeletal muscle biopsy: ragged red fibers with peripheral concentration of mitochondria(CPEO)

• Bloods: Mitochondrial DNA mutations
(CPEO), expanded CTG repeat in the dystrophica myotonica protein kinase (DMPK) gene (myotonic dystrophy), expanded GCG repeat (oculopharyngeal dystrophy)

Treatment

• Prisms if diplopia present (CPEO)

• Strabismus surgery if eyes in grossly eccentric position (CPEO)

• Ptosis props (CPEO)

• Ptosis surgery: risk of causing serious exposure keratitis due to the associated poor orbicularis function and absent Bell’s phenomenon (CPEO)

Other Diagnoses to Consider

• Myasthenia gravis
• Myotonic dystrophy
• Oculopharyngeal dystrophy
• CN III palsy
• Supranuclear gaze palsy

Question 19

Floppy Eyelid Syndrome

Answer 19

History

• Unilateral/bilateral ocular injection and irritation (nocturnal eversion of the extremely lax upper eyelid rubbing on the pillow)

• History of obstructive sleep apnoea (OSA) ± wearing a CPAP mask at night
• If no history of OSA ask about snoring, sleepless nights, daytime fatigue

Examination

• Papillary conjunctivitis

• Upper eyelid laxity, eyelid can be folded on itself and easily turned inside out

Investigations

• If patient symptomatic from OSA, refer to sleep specialist

Treatment

• Protecting eye with an eye shield at night (trial for a few weeks is a good test to see if lid tightening will improve the irritation)

• Horizontal lid tightening of the upper eyelid (usually pentagonal wedge resection)

Question 20

Dermatochalasis

Answer 20

History

• History of dry eye (sensitivity to moving air, from ceiling fans, air vents, or windshield defrosters) and use of artificial tears:
relative contraindication for blepharoplasty procedures —
less skin and muscle removal required

• History of CN VII palsy

• History of previous blepharoplasty: any
remaining ptosis is likely from brow ptosis

Examination

• Examine height and contour of brow (normal male brow is at the rim and relatively flat; the normal female brow is above the rim and arched temporally).

Judge height by palpating brow between your index finger and thumb relative to the orbital rim. (Look for ptotic brow hanging over the superior orbital rim); is there a generalised ptosis of the brow or is there more of a mild temporal droop? Brow furrows indicate that the patient is trying to see by using the brows to elevate the lids

• Examine for extra-tissues in the upper skin fold: estimate the amount of redundant skin and muscle in the skin fold by lifting the brow into the normal position at or above the rim, if you lift the brow higher you can see any fullness of sulcus if there is prolapsed orbital fat present (central or nasal fat)

• Examine the upper eyelid height: determine MRD1 (normal MRD1 as redundant upper eyelid skin does not change the eyelid position) by elevating the upper skin fold slightly to check the position of the upper eyelid margin, record levator function (not necessary if ptosis repair is not being considered)

• Examine the lower eyelid: look for prolapsed orbital fat (medially/laterally), look for redundant skin and muscle (any lower eyelid malar bags or festoons), estimate lower lid laxity (lid distraction test — normally the eyelid should not pull more than 6 mm away from eyeball, snap test with lower eyelid pulled down and released — normally lid returns to position without a blink or with one blink)

• Examine anterior segment: Look at size of tear lake and the presence of any corneal staining

Investigations

• 24-2 HVF: performed with eyelids in relaxed ptotic position and with the eyelids taped open. An improvement in the superior visual field defect of at least 12° is required

Treatment

• Browplasty: entire brow, temporal brow
• Upper lid blepharoplasty (removes redundant skin and muscle from the upper skin fold with variable amounts of fat excised depending on
the amount of fat prolapse)

– Indications:

Functional (vision blocked by redundant skin fold)

Cosmetic

– Surgical technique: skin marking (skin crease, upper limit of skin excision — should leave between 10 and 15 mm of skin between the eyebrow hairs and the skin crease), anaesthesia, skin incision, skin and muscle excision, fat excision, closure

– Complications:

Postoperative: asymmetry, reoperation, scarring, corneal exposure, lagophthalmos, blindness (retrobulbar haemorrhage — requires opening of surgical wound)

• Lower lid blepharoplasty

Causes of a pseudo-ptosis

• Excessive skin: brow ptosis, dermatochalasis

• Inadequate globe size: microphthalmos, phthisis bulbi, prosthesis

• Incorrect globe position: enophthalmos, hypotropia

• Contralateral lid retraction

• Contralateral large globe

• Contralateral proptosis

Question 21

Marcus-Gunn Jaw Winking Syndrome

Answer 21

Definition
• A congenital miswiring of the CN V (pterygoid muscles) gets misdirected to CN III (levator muscle)

History
• Ptosis onset from birth
• History of amblyopia

Examination
• Partial ptosis (mild to severe) in primary position
• Poor levator function in majority of patients. A few patients will have good levator function
• Elevation of ptotic lid with movements of the mouth

Treatment
• If poor levator function and significant synkinesis: extirpation of the levator to eliminate the abnormal movements and a frontalis sling operation to elevate the upper lid

• If good levator function and minimal synkinesis: levator aponeurosis advancement

Question 22

Myasthenia Gravis

Answer 22

History

• Variable ptosis and diplopia (worse towards the evening/with exercise)

• Any breathlessness, swallowing problems or choking episodes

Examination

• Unilateral ptosis ± contralateral pseudo-lid retraction (consequence of Hering’s law) or bilateral ptosis

• Ocular motility disturbance (any pattern) with always normal saccadic velocities

• Fatigability: ask patient to look up for 30–60 s and upper eyelid will fatigue and slowly drop

• Cogan’s eyelid twitch: patient to look down for 20 s and then at object in the primary position — positive if lid overshoots

• Normal pupil exam

Investigations

• Tensilon test
– Pretreatment requirements — ensure IV
atropine, resuscitation equipment, and trained staff is on hand, cardiac monitoring (ECG) essential

– Technique — give 2 mg edrophonium IV and if no ill effects at 30 s, give further 8 mg edrophonium IV. Compare pre- and post-test ptosis or motility disorder (Hess)

– Possible side-effects — increased salivation, sweating, bronchospasm, hypotension, bradycardia, arrhythmia

• Ice pack test — measure ptosis, ice cubes in rubber glove with patient holding it over their eyelid for 2 min, re-measure ptosis: positive if ≥2 mm improvement

• Serum antibodies — anti-Ach receptor antibodies (50% ocular myasthenia, 95% generalised myasthenia) — negative test does not rule out MG

• Single fiber EMG — reduction in action potential amplitude

• Bloods — TFT (MG associated with Graves disease in 4–10%)

• CT chest — thymoma

Treatment

• Co-manage with a neurologist
• Ocular manifestations: Lid crutches for ptosis,surgical ptosis correction if medical treatment unsuccessful although variability remains, prisms for diplopia

• Systemic manifestations:

– Medical treatment — pyridostigmine (anti-acetylcholinesterase), immunosuppression (oral prednisolone to reduce dose of pyridostigmine, azathioprine, AZT, plasmapheresis and IV immunoglobulin for
myasthenic crisis)

– Surgical treatment — thymectomy

Question 23

Basal Cell Carcinoma (BCC)

Answer 23

Classification of BCC

• Nodular

• Morpheaform: sclerotic plaques or papules,border not defined

• Superficial: scaly patches or papules (mimics eczema or psoriasis)

• Pigmented: areas of brown and black pigment seen in lesion along with signs similar to nodular

History

• History of sun exposure

• Positive family history of BCC: Gorlin’s syndrome (basal cell naevus syndrome) — AD, predisposes patients to multiple BCCs, associated with jaw cysts, palmar pits, skeletal abnormalities (syndactyly of the digits, sprengel deformity — scapula displacement and limitation of shoulder movement)

• History of xeroderma pigmentosum

Examination

• Firm nodule with pearly borders with telangiectasia ± central ulceration (lesions are not tender and not painful to touch)

• Destruction of normal lid margin architecture when the lesion involves the lid margin — lashes are often lost

• Examine for signs of actinic skin damage: skin appears thin with deep wrinkles and furrows, changes in pigmentation include diffuse mottling or brownish patches known as solar lentigo, vessels of the dermis are visible due to loss of surrounding collagen in elastic tissue, tight skin with no wrinkles despite advancing age
• BCCs most commonly present in the lower lid, then the medial canthus, then the upper lid and then the lateral canthus

Investigations

• Incisional biopsy (only portion of lesion is removed): used to sample a lesion for diagnosis — best place to sample the tumour is at the periphery of the lesion and include areas of normal tissue, centre of lesion should not be sampled, especially if there is central ulceration — histopathological interpretation may yield only necrotic tissue

• Genetic testing: mutations in PTCH1 and SUFU genes (Gorlin’s syndrome)

Treatment

• Topical imiquimod 5% cream for small superficial BCCs

• Wide local excision using Moh’s micrographic tumour excision technique followed by eyelid reconstruction : after removal of a debulking layer, narrow margins of surrounding tissue including the sides and the base of the tumour bed are removed for frozen section analysis, the frozen section are interpreted by the excising surgeon, if any tumour remains the surgeon goes back to the exact site and removes more tissue, the process is repeated with small areas of excision until all tumour tissue has been excised

Characteristics suggestive of eyelid skin malignancy

• Ulceration: often associated with bleeding, malignant lesions do not tend to be painful, nor are they tender to touch

•Induration:all malignancies tend to be firm or indurated

• Irregularity: irregular margins and asymmetric shapes

• Pearly borders and telangiectasia (dilated and irregular vessels): pathognomonic of BCC, heaped up
edges often surround an area of central ulceration

• Loss of eyelid margin architecture: malignancy may destroy the normal architecture of the lid margin,
suspect malignancy when an area of lash loss or lid margin destruction is present

Referrals of BCCs into Secondary Care (NICE Guidance [NG12])

• Consider routine referral for people if they have a skin lesion that raises the suspicion of a BCC

• Only consider a suspected cancer pathway referral (for an appointment within 2 weeks) for people with a skin lesion that raises the suspicion of a BCC if there is particular concern that a delay may have a significant impact, because of factors such as lesion site or size

Question 24

Eyelid reconstruction

Answer 24

Repair of full-thickness eyelid defects up to 25%:

Primary/direct eyelid margin repair:

• The primary eyelid margin repair begins with identifying the appropriate anatomic landmarks of the eyelid, especially the
landmarks of the lid margin.

• The strength of the closure is in sutures placed in the tarsal plate

• Eyelid wound margin eversion is necessary to prevent lid notching

• Steps of eyelid margin repair are:

– Inject local anaesthetic

– Align the lid margin (7/0 vicryl vertical mattress suture passed through the meibomian gland orifices to align and evert the lid margin)

– Suture the tarsal plate (use 2–3 interrupted 5/0 vicryl sutures passed in a lamellar fashion to align the tarsal plate)

– Suture the lid margin (place a 7/0 vicryl vertical mattress suture anterior to the gray line — this suture should align the
eyelashes and provide eversion of the lid margin)

– Close the skin (5/0 vicryl interrupted sutures)

• If the closure is under too much tension or the lower lid retracts inferiorly under the globe do a lateral canthotomy and cantholysis — if there is still too much tension
• Perform a Tenzel flap procedure, advancing tissue from the temple to form a new lid margin

• If the defect involves most of the lower eyelid, you should start with a Hughes flap procedure

• If the defect involves most of the upper eyelid, you should start with a Cutler Beard procedure

Repair of full-thickness eyelid defects of 25–50%:

Canthotomy, cantholysis, and eyelid margin closure:

• The canthotomy (angle canthotomy incision slightly superiorly for lower eyelid and angle canthotomy incision slightly inferiorly for upper eyelid) and cantholysis are used to release the lateral aspect of the lid to allow the lid margin to be closed under less tension

• Perform a primary lid margin repair and close the canthotomy

Repair of lid defects of 50–75%:

The Tenzel semi-circular flap:

• Steps of the Tenzel procedure are:
– Inject local anaesthetic: draw an arched line extending superiorly (lower lid) or inferiorly (upper lid) from the lateral canthus in a curve

– Perform lateral canthotomy and cantholysis: angle canthotomy superiorly as the canthotomy incision will continue as the Tenzel flap.

– Form and mobilise the Tenzel flap: dissect a myocutaneous flap posterior to the orbicularis muscle in the preseptal plane

– Perform a primary lid margin repair and close the flap

Repair of lower lid defects of 75% or greater:

(a) The Hughes procedure:

• Used to reconstruct the posterior lamella of a full thickness lower eyelid defect that is too wide for the use of a Tenzel flap (no
lashes on lower eyelid)

• Procedure provides a flap of tarsus and conjunctiva from the upper eyelid, which is sewn into the lower eyelid. This
tarsoconjunctival flap carries its own blood supply because it remains attached to the upper eyelid for 4 weeks

• An anterior lamella is provided using a myocutaneous advancement flap or FTSG

• Steps of the Hughes procedure:

– Inject local anaesthetic

– Measure the lower eyelid defect

– Form the tarsoconjunctival flap: leave 3 mm of intact superior lid margin to prevent upper lid entropion, make a horizontal cut parallel to the lid margin full thickness through the tarsus, dissect tarsus off the underlying orbicularis muscle and levator aponeurosis superiorly to the top edge of the tarsus, dissect a tissue plane between Muller’s muscle and the conjunctiva up to the superior fornix, make vertical cuts in the conjunctiva to bring down the tarsal flap
– Suture the flap into the lower eyelid defect
– Complete the anterior lamellar repair

– 4 weeks later, open the eyelids by excising the flap. Cut slightly above the lower lid margin

(b) Free tarsal graft:

• Harvested from the contralateral upper lid to be used as a posterior lamellar replacement for lower eyelid defects

• Advantage is that it is a one staged procedure

• Disadvantage is that it does not have a blood supply, so it must be covered with a myocutaneous advancement flap

Repair of upper lid defects of 50% or greater:

(a) The Cutler Beard procedure:

• Used to repair large full thickness defects of the upper lid.

• Two-stage lid sharing procedure

• A width of full thickness lower eyelid below the tarsal plate is used to reconstruct the upper eyelid defect

• The eyelids are sewn closed for several weeks before the second stage procedure (6–8 weeks later) to open the eyelids is
performed

(b) Free tarsal graft and bipedicle flap:

• Use a free tarsal graft from contralateral upper lid to fill the posterior lamellar defect

• Make a horizontal incision in the upper lid anterior lamella and advance a bipedicle flap of skin and muscle inferiorly to vascularise the free tarsal graft

• Place a free skin graft over the defect where you borrowed the tissue for the bipedicle flap.

Question 25

Actinic keratosis

Answer 25

Examination
• Multiple flesh coloured, yellowish, or brownish macules or papules ± cutaneous horn, depending on the degree of hyperkeratosis, which are rough to touch

• Upper lid is rarely a site of actinic keratosis because of shading of the skin by the prominence of the superior brow

Investigations

• Perform an incision biopsy if there is any doubt of the underlying diagnosis

• If a keratin horn is present, perform a deep excision biopsy including the base of the horn to determine the diagnosis

Treatment

• Monitor for formation of squamous cell carcinoma

• Treatment options: excision, topical application of imiquimod or 5-FU, cryotherapy

Useful information about actinic keratosis

• Premalignant skin lesion, the precursor to squamous cell carcinoma

• Lesions appear in the context of sun damaged skin on the face, hands, bald scalp, and ears

Question 26

Melanocytic Naevus

Answer 26

History
• Presentation age: at birth — congenital naevus, teenaged child — junctional or compound naevus, older adult — intradermal naevus

Examination

• Junctional naevus: brown flat lesion

• Compound naevus: darker dome-shaped
lesion

• Intradermal naevus: elevated non-pigmented lesion

Investigations

• Punch biopsy (incisional biopsy technique where a disposable skin dermatome, like a corneal trephine, is used to “core” out a sample of the lesion) should be performed if a naevus shows a dramatic change in colour or shape

Treatment

• No treatment required for majority of naevi

• For intradermal naevus (elevated nonpigmented naevus) causing irritation or disfigurement: shave biopsy (incisional biopsy technique with lesion shaved off flush with the lid margin)

Life cycle of a melanocytic naevus

• Junctional naevus: flat small oval or round light to dark brown macules — at border of epidermis and dermis

• Compound naevus: raised and dome shaped — extending from epidermis into dermis

• Intradermal naevus: raised with loss of colour returning to light brown or flesh colour — within dermis

Characteristics of benign pigment cell tumours (e.g. naevus)

• Uniform in colour (small variations from light brown to brown are normal)

• Regular smooth borders (smooth edges)

• Symmetric shape (lesion can be folded on itself)

Characteristics of malignant pigment cell tumours (e.g. melanoma)

• Recent onset of pigmented lesion

• Change in existing pigmented lesion (shape, size, colour)

• Irregular margins

• Asymmetric shape (lesion cannot be folded on itself)

• Large size greater than 6 mm in diameter

• Colour change or presence of multiple colours