The anterior eye Flashcards
what are the tear film layers in order from outer to inner
- lipid layer
- aqueous layer
- aqueous phase (MUC 5AC)
- glycolax (MUC1), (MUC 4), (MUC 16)
- mucinous phase
- epithelial surface with microvilli
what can ocular surface and tear film disorders cause?
DED
MGD
CL DISCOMFORT
what are two types of dry eye disease? what are there symptoms?
dry eye syndrome (DES) and keratoconjunctivitis sicca (KCS)
-dryness
-discomfort
-irritation
-reduced vision
what are the two types of dry eye?
-aqueous deficiency where is affects the lacrimal gland function
-evaporative dry eye
what is the most frequent cause of DED?
MGD
why is it important to prevent DED
-it is very expensive to treat i.e.. cost of referrals, Px etc
what are the 4 inter-related mechanisms responsible for DED
-tear instability
-tear hyperosmolarity
-inflammation
-ocular surface damage
what is evaporative dry eye?
related to causes from
-lids such as MDG and blink problems
-ocular surface such as mucin or CL-related
what is another name for MGD
posterior blepharitis
how is obstructive MGD caused?
- terminal duct obstruction
- caused by hyperkeratinisation of the ductal epithelium, keratinised cell debris and increased meibum viscosity
- causes normal clear oily secretions to become semi-solid, toothpase like plaques
what kind of populations are most likely to have MGD?
mainly asian populations
what is the vicious cycle for dry eye disease?
- damage to ocular surface
- goblet cell loss
- mucin loss
- tear film instability
- excessive tear evaporation
- hyperosmolarity
8.inflammation - keratinisation of gland orfices
which causes inflammation and the cycle repeats
what is the cycle for MGD?
- bacterial proliferation causes increased exotoxin release
- lipases and esterases destabilise the tear films lipid layer
- this causes a rise in meibum melting point
- which causes meibomian gland dysfunction
which leads to proliferation of bacteria and the cycle repeats
What are the consistent risk factors for Dry eye?
-increasing age
-CL wear
-being female
-Asian ethnicity
what are the signs of dry eye?
-fluorescein staining, small tear meniscus height, TBUT <10
what are the symptoms of dry eye?
-discomfort
-dryness
-irritation
-grittiness
-fluctuating vision which may get worse throughout the day
-vision that gets worse with wind, smoke, heat and prolonged near activities
how do you diagnose dry eye?
-use the dry eye questionnaire to determine if they have symptoms of dry eye (difficult if time is limited)
-check tear film stability, tear film osmolarity or ocular surface staining
-check tear meniscus
how do you manage dry eye?
-dietary advice of eating more oily fish for omgea 3
-recommend ocular lubricants such as preservative free artificial tears
-wear protective glasses/ moisture chamber glasses
-use specialist care methods if these don’t work
-refer to secondary care if nothing else works
what specialist care methods can be used when treating dry eye?
-punctum plugs
-scleral / bandage contact lenses
-pharmacological management like topical steroids
what could be differential diagnoses to dry eye?
computer vision syndrome and digital eye strain
what are the risk factors for MGD?
-wearing CLs
-prolonged screen use (as it reduced blink rate)
what are the signs of MGD?
-changes to secretion of the gland
-saponification of tears
-gland plugging/ paste like yellowish secretion
diagnosis of MGD
-inspect the glands for the signs
-push on the meibomian glands to clear the blockage
MGD treatment?
squeeze the meibomian glands to clear the blockage
MGD management?
- use products to heat your eyes like heated eye mask
- massage the eyelids to clear the blockages
- clean the eyelids
in MGD when should you refer to secondary care?
-sometimes when you have peads px
-if they may have suspected underlying conditions or unidentified systemic diseases
-secondary complications like vascularisation, corneal scarring and infection
-abnormal lid anatomy/ function
-persistent/ severe Sx that dont want to respond to primary management after 4-12 weeks
Name two types of corneal inflammation
-marginal keratitis
-CL associated infiltrative events (CIE’S)
what is the aetiology of marginal keratitis?
an inflammatory response of the peripheral cornea to bacteria exotoxins instead of direct inocculation
what are the predisposing factors
-bacterial blepharitis
-sometimes contact lenses
what are the signs of marginal keratitis?
-redness and inflammation of limbus and bulbar conjunctiva due to excess blood in the vessels
- stromal infiltrate ( typically adjacent to the limbus and separated
by an interval of clear cornea)
-ulcers (they stain with fluorescein)
what are the symptoms of marginal keratitis
-ocular discomfort
-lacrimation
-red eye
-photophobia
what is the non pharmacological management of marginal keratitis?
-initially address predisposing factors e.g. contact lenses
-regular lid hygiene for associated blepharitis
what are the pharmacological managements for marginal keratitis?
-ocular lubricants for symptomatic relief
-systemic analgesia when needed (painkillers)
-topical antibiotic use to reduce bacterial load plus topical steroid to reduce inflammation
Name three CIEs
-contact lens-associated peripheral ulcer (CLPU)
-contact lens associated infiltrative keratitis
-contact lens associated acute red eye (CLARE)
what is the aetiology for CIEs?
a self limiting inflammatory response of the cornea affecting the anterior stroma
what are the patient related pre disposing factors of CIEs?
-blepharitis
-male sex
-being <25 years old
-smoking
-having previous Hx of CIEs
what are the predisposing factors of CIEs for patients who wear CLs?
-long term lens wear
-overnight wear
-silicon hydrogel material
-tight fit lens
-MSPs
-poor lens hygiene
what are the symptoms of CIEs?
-red and watery eye
-foreign body sensation
-photophobia
(some cases are even asymptomatic)
what are the signs of CIE’s?
-peripheral anterior stromal infiltrates, usually small
-ulcer formation
-conjunctival hyperaemia
-adjacent limbal hyperaemia
-epiphoria
-anterior chamber inflamed to some degree
-usually unilateral
Give the non-pharmacological management of CIE’s
- address the modifiable risk factors
-temporarily discontinue lens wear as this can resolve signs and symptoms within 48 hrs
-advise against extended CL wear
-evaluate lens fit and care regime
-reinforce education concerning lens hygiene and wearing schedules
-warn about possibility of recurrence as if condition recurs, then switch to daily disposables
-lid hygiene if blepharitis is present
give the pharmacological management of CIEs
-ocular lubricants for symptomatic relief
-topical antibiotic may be indicated if blepharitis present
what is the aetiology of bacterial keratitis
sight threatening infection of the cornea
what are the most commen bacterial corneal pathogens with their types
-Pseudomonas sp. (Gram -ve)
-Staphylococcus sp. (Gram +ve)
-Streptococcus sp. (Gram +ve)
What are the predisposing factors of bacterial keratitis?
- Contact lens wear
- Ocular surface disease, ocular trauma/surgery
- Immunocompromised
- Lid margin infection
What are the most common fungal corneal pathogens?
-Candida sp. (yeast-like)
-Fusarium sp. (filamentous)
- Aspergillus sp (filamentous)
what are the predisposing factors of fungal keratitis specifically?
-being immunocompromised
-having had a trauma involving organic materials
what are signs that are specific to fungal keratitis?
-deep lesions with a feathery edge
-raised profile
-satellite lesions
-endothelial plaque
what are the symptoms of bacterial/ fungal keratitis?
-pain (usually acute onset and quickly gets worse)
-redness
-photophobia
-blurred vision (if lesion is on visual axis)
-discharge
-yellow spot on cornea
what are the signs of both bacterial/ fungal keratitis?
*Lid oedema
* Epiphora
* Discharge (mucopurulent or purulent)
* Conjunctival hyperaemia and infiltration
* Corneal lesion usually single (central or mid-
peripheral)
* Excavation (cavity) of epithelium, Bowman’s layer, stroma
(tissue necrosis)
* Stromal infiltration beneath lesion
* Stromal oedema with folds in Descemet’s
membrane
* Anterior chamber activity (flare, cells, hypopyon or
coagulum if severe)
what is the non-pharmacological management of bacterial/ fungal keratitis?
remove CLs but keep them and the case to determine the culture)
what are the non pharmacological management techniques of bacterial/ fungal keratitis?
-emergency referral to secondary care
what are the predisposing factors of acanthamoeba keratitis?
-wearing CLs
-* inadequate contact lens disinfection
* use of non-sterile solutions
* tap water rinsing of lenses and/or storage cases
* contamination of storage case with bacteria and fungi (± biofilm) which provide substrate for
Acanthamoeba
* exposure to shower, pool, or hot tub water
-corneal trauma with exposure to soil or contaminated water
what are the symptoms of AK?
*Pain (may be severe and out of proportion to degree of ocular inflammation; may also be painless in the early stages)
* Visual disturbance/loss, Redness, Watery eye, Photophobia
* May be a long history and condition may be misdiagnosed as herpetic, bacterial or fungal keratitis
what are the signs of AK?
-conjunctival and limbal hyperaemia
-epiphoria
-reduced VA in later stages
what are the early signs of the corneal lesions of AK?
*punctate epitheliopathy
* epithelial or subepithelial infiltrates
* pseudodendrites
* radial keratoneuritis (infiltrates along corneal nerves)
* recurrent breakdown of the corneal epithelium
what are the later signs of corneal lesions of AK?
- deep inflammation of the cornea consisting of a central
or paracentral ring-shaped or disciform stromal infiltrate
or abscess - stromal thinning
- extension of inflammation into sclera
- anterior chamber cells and flare
- hypopyon (inflammatory cells in anterior chamber of eye)
what is management for AK?
-remove CLs
-refer to secondary care EMERGENCY
what are the two types of viral keratis?
hepes simplex keratitis and herpes zoster ophthalmicus
What are the two types of of Herpes simplex virus? (HSV)
HSV-1 mainly infects mucous membranes ‘above the waist’
HSV-2 mainly infects mucous membranes ‘below the waist’
what are the predisposing factors of HSK?
- Poor general health, immunodeficiency, fatigue, steroids, immunosuppressive drugs, previous HSV
infection - Aggravating factors – UV light, fever, extreme heat/cold, infection, trauma
what are the symptoms of HSK?
- Usually unilateral, rarely bilateral
- Variable symptoms, can include pain, burning, irritation, photophobia, blurred vision, redness, reduced
VA
what are the epithelial signs of HSK?
-Initial punctate lesions, coalescing into a dendriform pattern
-* Dendritic ulcer, single or multiple opaque cells arranged in a stellate pattern progressing
to a linear branching ulcer, terminal bulbs may be visible
* Dendritic lesions stain with fluorescein
* Associated with reduced corneal sensitivity
what are the stromal signs of HSK?
- Stromal infiltrates, vascularization, oedema and opacification
- Non-necrotising oedma is localized & often self-limiting,
- Necrotizing inflammation is widespread, infection progressed to ulceration, necrosis and
possible perforation
what is the most severe sign of HSK?
metaherpetic ulcer
what is the management for herpes simplex keratitis?
- Aciclovir 3% ointment (continue for 3 days after healing complete)
- Gangiclovir 0.15% ophthalmic gel (continue for 7 days after healing complete)
*emergency referral if the stroma is involved or the Px is a child, contact lens wearer or has bilateral infection
what is herpes zoster infection?
involvement of the ophthalmic division of the trigeminal nerve due to infection
what microbe causes HZO?
human herpes virus -3 (HHV-3)
what are the predisposing factors of HZO?
-age
-being immunocompromised
what are the symptoms of HZO?
- Pain and altered sensation (often described as “tingling“, “burning” or
“shooting”) of the forehead on one side - Rash affecting forehead and upper eyelid appears a day to a week later
General malaise, headache, fever - Ocular symptoms in acute phase: discomfort, discharge, redness, pain,
photophobia
what are the signs on the skin with HZO?
- unilateral painful, red, vesicular rash on the forehead and upper eyelid, does
not cross the midline, crusts after 2-3 weeks - Hutchinson’s sign, (indicating nasociliary nerve involvement) skin lesions on the side of the tip of the nose, correlates strongly with ocular involvement.
What are the ocular signs of HZO?
*Early onset or within one month after the onset of the skin rash therefore
patients need to be monitored
* Mucopurulent conjunctivitis (common), associated with vesicles on the lid
margin; usually resolves within 1 week
* keratitis causing punctate epithelial – early sign, pseudodendrites – fine, multiple stellate lesions (around 4-6 days), disciform – 3 weeks after the rash (occurs in 5% of cases), reduced corneal sensation (neurotrophic keratitis), occurring in approximately 13% of HZ keratitis cases
* Episcleritis occurs in around one third of cases
for HZO, what is the management?
-advice avoidance of contact with elederly, pregnant or immunocompromised people
-advice good diet and lots of fluids
-topical lubricant for ocular symptoms
-pain relief like paracetamol
-emergency referral to GP for systematic anti viral treatment for acute skin lesions as this will reduce percentage of eye disorders if this gets treated within 72hrs of onset
-maintain low threshold to refer to secondary care
For HZO, when would you refer to secondary care?
-if deeper cornea involved
-anterior uveitis present
-raised IOP
name 2 conjunctival infections
-viral conjunctivitis
-bacterial conjucntivitis
name a conjunctival inflammation
allergic conjunctivitis
name 5 conjunctival degenerations
➢ Pinguecula
➢ Pterygium
➢ Retention cyst
➢ Chalasis
➢ Concretions
what are the three non-infectious types of conjucntivitis?
-allergic
-toxic
-autoimmune
what are the signs of viral conjunctivitis?
- Watery discharge
- Conjunctival hyperaemia (intense?) and chemosis
- Follicles on palpebral conjunctiva
- Petechial (pin-point) subconjunctival haemorrhages
what are the symptoms of viral conjunctivitis
- May be preceded by ‘flu-like’ symptoms
- Redness, discomfort (burning/grittiness), watering
- Often unilateral at first, becoming bilateral. First eye usually more affected.
- Systemic malaise (overall feeling weakness/unwell)
What are the management points for viral conjunctivitis?
Advise self-limiting, resolving in 1-2 weeks
* Hygiene advice – highly contagious
* Do not share towels/pillows
* Avoid close contact if working in patient-facing roles
* No recommended exclusion period from school or nursery
* Cold compress and lubricants for symptoms
* Discontinue contact lens wear until resolved
* Antibacterial agents not effective in viral conditions
* Current antivirals not effective in adenovirus infection
What are the signs of bacterial conjunctivitis?
-thick mucopurulent discharge
-lid crusting
-conjunctival hyperaemia most obvious in the fornices
-mild papillary reaction
what are the symptoms of bacterial conjunctivitis?
- Redness, discomfort (burning/grittiness)
- Vision may be blurred by discharge
- Sticky eyelids/lashes (may stick closed overnight)
- Usually bilateral but one eye may be affected 1-2 days before the other
what are the management options for bacterial conjunctivitis?
- Advise self-limiting, resolving in 5-7 days without treatment
- Return if symptoms persist beyond 7 days
- Hygiene advice – contagious
- Do not share towels/pillows
- No recommended exclusion period from school or nursery
- Bathe/clean eyelids to remove crusting
- Cease CL wear until resolved
- Topical antibiotics?
what antibiotics would you give to someone with bacterial conjunctivitis?
Chloramphenicol 0.5% (eyedrop) or 1% (ointment)
* Azithromycin 1.5%
* Fusidic acid 1% (note: high cost and narrower spectrum of activity
what are the two types of allergic conjunctivits?
acute and chronic
what are the two types of chronic allergic conjunctivitis?
seasonal and perennial
what are the 4 features that make up the aetiology of acute conjunctivits?
-type I IgE-mediated response
-common in children
-self limiting
-allergen is often unidentified
what are the signs of acute allergic conjunctivitis?
- Lid oedema and erythema
- Conjunctival hyperaemia and chemosis
- Watery or mucoid discharge (mild)
- Usually no papillae
- No corneal involvement
what are the symptoms of acute allergic conjunctivitis?
*Sudden eyelid swelling
* Ocular itching
* May be unilateral (if direct contact response)
how do you manage acute allergic conjunctivitis?
- Reassure patient
- Most cases resolve spontaneously within a few hours
- Advise against eye rubbing
- Cool compress to relieve symptoms
- If known allergen, avoid future exposure
what kind of immune response does chronic conjunctivitis trigger?
type I hypersensitivity (IgE-mediated) reaction to airborne allergens
how do the symptoms of chronic conjunctivitis come about and what are they?
Conjunctival mast cell degranulation releases histamine, causing:
-dilation of vessels
-increased permeability of blood vessels -itching
What are the predisposing factors of chronic conjunctivitis?
History (personal or family) of allergic disease (hay
fever, asthma, eczema, food or drug allergy)
* Allergic rhinitis
what are the signs of chronic conjunctivits?
- Mild to moderate lid oedema
- Hyperaemia and chemosis of conjunctiva
- Diffuse papillary reaction
- No corneal involvement
what are the symptoms to chronic conjunctivitis?
- Itchy eyes (main symptom)
- Red eyes, watering
- Sneezing, watery nasal discharge
- Timing of symptoms (seasonal vs perennial
how do you manage chronic conjunctivitis?
- Identify allergen(s) – careful H+S and diary matching to pollen calendars
- Avoid allergen if possible
- Advise against eye rubbing
- Cool compress and ocular lubricants to relieve symptoms
- Topical mast cell stabilisers – sodium cromoglicate 2%; lodoxamide 0.1%
- Topical antihistamines – antazoline 0.5%
- Combination – olopatadine 0.1%; ketotifen 0.025%
- Topical NSAID – diclofenac sodium 0.1%
- Systemic antihistamine (oral) – cetirizine; loratadine
is seasonal or perennial conjunctivitis more common?
less common and also less severe
how are seasonal and perennial conjunctivitis different?
seasonal is caused by seasonal allergens like grass and pollen. Perennial is caused by non-seasonal allergens like dust mites or animal dander
what are the signs of pinguecula?
- Bilateral, more commonly nasal, interpalpebral
- Conjunctival thickening; elevated and less transparent
- Mild hyperaemia?
what are the predisposing factors for pinguecula?
-older age, male
-UV so being closer to the equator and occupation/ lifestyle
-chronic irritation from dust/ wind
-contact lens wear
what are the symptoms for pinguecula?
Asymptomatic? Or mild foreign body sensation
* Occasional cosmetic concern
what are the differential diagnoseses for pinguecula?
-pterygium
-retention cyst
what are the management plans for pinguecula?
- Reassure patient - benign
- UV protection advice
- Cold compress if inflamed
- Ocular lubricants
what do you prescribe for pingueculitis?
mild topical steroid
what are the predisposing factors for pterygium?
-older age, male
-UV
-dry arid climate
what are the signs for pterygium?
- Bilateral, usually nasal, asymmetrical
what are the symptoms for pterygium?
- Asymptomatic? Or mild irritation
- With-the-rule astigmatism
- Severe cases: extend over visual axis
*cosmetic concern
What are the management options for ptreygium?
-* UV protection advice
* Cold compress if inflamed
* Ocular lubricants
* Severe cases: surgical excision
what are the management options for a retention cyst if it becomes problematic?
-topical anaesthetic
-hypodermic needle
what are the signs of chalasis?
Fold of redundant conjunctiva, often protrudes over lid margin
what are the symptoms of chalasis?
watering if punctum is obstructed causing foreign body sensation
what causes chalasis?
mechanical stress and dry eye
what are the management options for chalasis?
- Ocular lubricants, treat blepharitis
- If severe, conjunctival resection (surgery)
what are concretions?
small yellow/white lesions on the palperbral conj.
what are the predisposing factors for concretions?
being 50+
-chronic inflammation like conjunctivitis or old chalazion
what are the signs of concretions?
Small (<1-2mm) yellow/white bodies with distinct edges
* Appear larger if confluent
what are the symptoms of concretions
-asymptomatic
-if they erode through eopithelium you get epiphoria and hyparaemia
what are the differential diagnoses for concretions?
-inclusion cysts
-follicles
what is the management plans for concretions
usually nothing but if symptomatic then use ocular lubricants
how can you remove eroded concretions?
sit the patient under the slit lamp and administer topical anaesthetic to remove them with a hypodermic needle
what is a subconjunctival haemorrhage?
a rupture if the conjunctival/ episcleral blood vessels which causes bleeding into the subconjunctival space
what are the main spontaneous causes of a subconjunctival haemorrhage?
-idiopathic
-coughing/ straining
-systemic vascular disease like diabetes or hypertension
-medication like anticoagulants
what are traumatic causes of subconjunctival haemorrhage?
-injury
-eye rubbing
-ocular surgery/ procedure
-contact lens handling injury
what are the signs for subconjunctival haemorrhage?
Localised or diffuse red area, usually temporal or inferior
* Posterior border visible
* Usually unilateral
* No discharge
what are the symptoms for subconjunctival haemorrhage?
- Usually painless, sometimes mild ache or irritation
- Patient concern/alarm
what are the differential diagnoses for subconjunctival haemorrhage?
- Acute haemorrhagic conjunctivitis (viral, usually bilateral)
- Retrobulbar haemorrhage
how could you manage subconjunctival haemorrhage?
- Reassure patient (self-limiting), usually resolves in 1 - 2 weeks
- Cold compress for discomfort
- Ocular lubricants
- Return if problem doesn’t resolve or recurs
what is dellen? What is it associated with? What can severe cases cause?
localised corneal disturbance causing drying of the focal area due to impaired lubrication.
associated with adjacent elevated lesions like pinguecula or a large subconjunctival haemorrhage
descemetocele formation and corneal perforation
For exposure keratopathy what is it?
damage of the cornea caused by lagophthalmos with drying of the cornea despite normal tear production
what can cause lagopthalmos?
-neuroparalytic causes like facial nerve palsy or parkinsons disease
-mechanical like lid scaring or proptosis or tight skin due to eczema
what are symptoms of exposure keratopathy?
same as dry eye
what are the signs of exposure keratopathy?
-mild punctate epithelial changes involving the inferior 3rd of the cornea
-epithelial breakdown
-stromal melting occasionally leading to perforation
-inferior fibrovascular change with Salzmann degeneration may develop over time
-secondary infection
how can you treat reversible exposure keratopathy?
-artificial tears
-taping the lid closed at night
-bandage silicone hydrogel or scleral contact lens
-management of proptosis by orbital decompression
-temporary tarsorrhaphy
how can you treat permanent exposure keratopathy?
-permanent tarsorrhaphy
-gold weight upper lid insertion fot facial nerve palsy
What causes recurrent corneal epithelial erosion?
an abnormally weak attachment between the basal cells of the corneal epithelium and their basement membrane due to traumas which could be minor like eyelid cornea interactions while sleeping
what are the symptoms of recurrent corneal epithelial erosion?
-severe pain
-photophobia
-redness
-blepharospasm
-eye watering especially when waking in the middle of the night or in the morning
there’s usually a prior history of corneal abrasion
what are the signs of recurrent corneal epithelial erosion?
-pooling of fluorescein and rapid tear film breakup
-greyish rolled epithelium may be present
-signs of basement membrane disturbance like microcysts or punctuates are often present bilaterally in a stromal dystrophy and unilateral if injury is the cause
how do you treat acute symptoms of recurrent corneal epithelial erosion?
-antibiotic ointment four times daily and cyclopentolate 1% twice daily
-in severe cases can use bandage contact lens to alleviate pain but does not improve healing
-use antibiotic drops over ointment in severe cases
-debridement of heaped areas of epithelium with a sterile cellulose sponge or cotton tipped applicator
-topical diclofenac 0.1% to reduce pain
-hypertonic sodium chloride 5% drops 4x daily and ointment at bedtime to improve epithelial adhesion
why would you not use pressure patching to treat acute symptoms of recurrent corneal epithelial erosion?
as it may impair healing and does not improve comfort
how would you treat recurrent symptoms of recurrent corneal epithelial erosion?
-topical lubricant gel or ointment or hypertonic saline ointment at bedtime
-long term extended wear bandage contact lens
-anterior stromal puncture for localised areas off the visual axis
what systemic conditions are associated with keratoconus?
-down syndrome
-ehlers-danlos
-marfans syndrome
-osteogenesis imperfecta
what are some ocular conditions associated with marfans syndrome?
-vernal keratoconjunctivitis
-blue sclera
-aniridia
-leber congenital amaurosis
-retinitis pigmentosa
-persistent eye rubbing
when does keratoconus normally present?
in teens or twenties with features initially in one eye but other eye will eventually be affected (most pxs have no family history)
what are the symptoms of keratoconus?
-unilateral impairment of vision due to progressive myopia and astigmatism
what are the signs of keratoconus?
-oil droplet reflex in ophthalmoscopy at distance of 0.5m
-scissoring reflex in ret
-vertical deep stromal stress lines which disappear with pressure on the globe in volk
-progressive corneal protrusion with thinning at max apex
-epithelial iron deposits best seen with a cobalt blue filter seen as a ring
bulging of lower lid in downwards gaze
-steep keratometry readings
-corneal topography shows a (normally symmetrical) bow tie pattern of astigmatism
what is pellucid marginal degeneration?
a rare progressive peripheral corneal thinning disorder typically of the inferior cornea
what are the symptoms of pellucid marginal degeneration?
slow progressive blurring due to astigmatism
what are the signs of pellucid marginal degeneration?
-bilateral slow progressing crescentic 1-2mm band of inferior corneal thickening extending from 4 to 8 oclock 1mm from limbus
-no fleischer rings or Vigt straie unlike keratoconus
-corneal topography shows butterfly pattern with severe astigmatism and diffuse steepening of the inferior cornea
How is keratoglobus different to keratoconus?
cornea develops globular rather than conical
what is the inheritance of Cogan like?
usually sporadic, rare familial cases are autosomal dominant
what is Cogan?
epithelial basement membrane dystrophy
what does histology of cogan show?
thickening of basement membrane with deposition of fibrillary protein between the basement membrane and the bowman layer and basal epithelial hemidesmosomes are deficient
What is the onsent of cogan?
in the second decade and about 10% develop corneal erosions in the 3rd decade while remaining are asymptomatic throughout life
what are the signs of cogan?
-lesions seen with retroillumination or sclerotic scatter
-dot like microcystic epithelial lesions
-subepithelial map like patterns surrounded by a faint haze
-whorled finger print like lines
-blep-like subepithelial pebbled glass pattern
what is the inheritance pattern and histology of lattice corneal dystrophy?
-autosomal dominant
-amyloid deposits in the corneal stroma
what are the symptoms of lattice corneal dystrophy in the classic form and in the gelsolin type form?
-recurrent erosions which occur at the end of the 1st decade
-ocular irritation and late impairment of vision
what are the signs and treatment of the classic type of lattice corneal dystrophy?
signs:
-refractile anterior stromal dots coalescing into a relatively fine filamentous lattice that spreads gradually but spares the periphery
-a generalised stromal haze which may progressively impair vision
-reduced corneal sensation
treatment
-penetrating or deep lamellar keratoplasty is often required and recurrence is not uncommon
what are the signs and treatment of gesolin type of lattice corneal dystrophy?
ocular signs:
-sparse stromal lattice lines spread centrally from periphery
-impaired corneal sensation
systemic signs:
-progressive cranial and peripheral neuropathy, mask like facies and autonomic features
treatment
-keratoplasty is rare
what is the inheritance of granular corneal dystrophy?
autosomal dominant
how is the histology of granular corneal dystrophy different for type 1 and type 2?
-type 1 only shows hyaline deposits whereas type 2 shows both hyaline and amyloid deposits
what are the symptoms of type 1 granular corneal dystrophy?
-glare and photophobia
-blurring as disease progresses
what are the symptoms of type 2 granular corneal dystrophy?
-mild recurrent erosions
-visual impairment later in the disease
what are the signs of type 1 granular corneal dystrophy?
-discrete white central anterior stromal deposits like sugar granules separated by clear stroma
-gradual increase in number and size of deposits with deeper and outward spread, sparing the limbus
-gradual confluence and diffuse haze lead to visual impairment
impaired corneal sensation
what are the treatments of type 1 granular corneal dystrophy?
-penetrating
-deep lamellar keratoplasty
what are the treatment of type 2 granular corneal dystrophy?
usually not required
for Fuch’s endothelial corneal dystrophy, who is it more common in and what is it associated with?
more common in women and associated with slight increased prevalence of open angle glaucoma
what is the inheritance pattern of Fuch’s endothelial corneal dystrophy
mostly sporadic with some AD inheritance
what are the symptoms of Fuch’s endothelial corneal dystrophy
-gradually worsening burring
-blurring is worse in the morning due to corneal oedema
-onset usually middle age or later
what are the signs of Fuch’s endothelial corneal dystrophy?
-cornea guttata (irregular warts on Descemet membrane)
-specular reflection shows small dark spots caused by disruption of the regular endothelial mosaic
-central stromal oedema
-epithelial oedema in advanced cases causing microcysts
what are the treatment options for Fuch’s endothelial corneal dystrophy
-topical sodium chloride drops
-bandage contact lenses, cyloplegic drops
-antibacterial ointments and lubricants
what are the signs of arcus senilis?
-stromal lipid deposition
-band of lipid deposition wider in the vertical than the horizontal
-band is separated form limbus by a clear zone that may undergo mild thinning
What are the signs of vogt limbal girdle and how are they different for type 1 and type 2?
-white crescentic limbal bands composed of chalk like flecks
-centred at 9 oclock and/ or 3 o’clock
-tyoe 1 has a swiss cheese hole pattern while type 2 has no hole pattern
what are the causes of band keratopathy?
-chronic anterior uveitis
-glaucoma
-chronic corneal oedema
-age related
-hereditary causes
what are the signs of band keratopathy?
-peripheral interpalpebral calcification with clear cornea separating the sharp peripheral margins of the band from the limbus
-nodular advanced lesions
what is treatment for band keratopathy?
only treat if vision is threatened or if the eye is uncomfortable
-chelation for relatively mild cases
what can cause corneal graft rejection to be more likely?
-larger grafts of over 8mm in diameter
-infection
-glaucoma
-previous keratoplasty
what are the symptoms for corneal graft rejection
-blurred vision
-redness
-photophobia
-pain
many cases are asymptomatic
what are the signs of corneal graft rejection
depending on type of graft
-epithelial rejection= elevated line of abnormal epithelium
-subepithelial rejection = subepithelial infiltrates, deeper oedema
-stromal rejection = deeper haze
-endothelial rejection = linear pattern of keratic percipitates
how do you manage corneal graft rejection?
-early intensive treatment to reverse rejection
-preservative free topical steroids hourly for 24 hrs
-topical cycloplegia
-systemic steroids (oral prednisolone)
What are the Post-operative complications of laser refractive procedures?
-tear instability
-subepithelial haze
-epithelial ingrown under the flap
-persistent epithelial defects
