Glaucoma Flashcards
Aqueous secretion
By the ciliary epithelium of the ciliary body pars plicata
1. Sympathetic nervous system
➕beta 2 receptors
➖alpha 2 receptors
2. Enzymatic action: Carbonic anhydraseAqueous outflow
PC➡️pupil➡️AC➡️
1. Trabecular outflow (%90)➡️Schlemm➡️episcleral veins 2. Uveoscleral drainage (%10)➡️suprachoroidal space➡️venous circulation 3. Iris
Applanation tonometry-sources of error
- Inappropriate fluorescein pattern
- Pressure on the globe
- CCT
- Corneal oedema
- Astigmatism
- Incorrect calibration
- Wide pulse pressure
- Repetead readings over a short period
- Tight collar, breath-holding
Angle structures
- Schwalbe line
- Corneal wedge
- Trabeculum
- anterior: non-functional, whitish
- posterior: functional, pigmented
- Schlemm canal
- Scleral spur
- Ciliary body
- Iris processes
- Blood vessels
Grading of angle width
Schaffer system - Grade:
4⃣ (35-45): ciliary body
-myopia, PF
3⃣ (25-35): scleral spur
2⃣ (20): trabeculum
1⃣ (10): only Schwalbe
Slit angle: no angle structures+no iridocorneal contact
0⃣ (0): closed due to iridocorneal contactPathological findings-PAS
- Primary angle-closure glaucoma
- Anterior uveitis
- Iridocorneal endothelial (ICE) syndrome
Pathological findings-NV
- NV glaucoma
- Fuchs heterochromic cyclitis
- Chronic anterior uveitis
Pathological findings-Hyperpigmentation
- Physiological variant
- Pigment dispersion syndrome
- Pseudophakic pigment dispersion
- Pex syndrome
- Blunt ocular trauma
- Anterior uveitis
- Following acute angle-closure glaucoma
- Following YAG laser iridotomy
- Iris or angle melanoma or naevus
- Iris pigment epithelial cysts
- Naevus of Ota
Pathological findings-Trauma
- Angle recession
- Trabecular dialysis
- Cyclodialysis
- Foreign bodies
Pathological findings-Blood in the Schlemm canal
- Physiological variant
- Carotid-cavernous fistula and dural shunt
- Sturge-Weber syndrome
- Obstruction of the VCS
OD size
1.5-1.7 mm
Subtypes of glaucomatous damage
- Focal ischemic discs
- localized field defects
- Myopic disc with galucoma
- dense superior and inferior scotomas
- younger, male patients
- Sclerotic discs
- peripheral visual field loss
- older patients
- Concetrically enlarging discs
- diffuse visual field loss
Non-specific signs of glaucomatous damage
- Disc haemorrhages
- most: inferotemporal
- Baring of circumlinear blood vessels
- early sign
- Bayoneting
- Collaterals btw two veins at the disc
- uncommon
- Loss of nasal NRR
- moderately advanced
- The laminar dot sign
- advancing
- Sharpened edge / sharpened rim
- advancing
Peripapillary changes in glaucoma
- Alpha(outer) zone
- Beta(inner) zone
- its location seems to indicate the orientation of likely visual field loss
RNFL defects in glaucoma
- Localized wedge-shaped defects
- Diffuse defects with indistinct borders
- use red-free(green) light
- not specific (can be seen in neurological diseases/normal people)
The visual field
50
⬆️
(T)90⬅️ ➡️60(N)
⬇️
70
-blind spot: temporal btw 10-20 and slightly below the horizontalApostilbs (asb)
The intensity or brightness of a light stimulus
Decibels (dB)
Sensitivity of retina
False positives in perimetry
-The printout appears;
abnormally pale
-SITA➡️>%15
Full-threshold➡️>%33 is highly significant
False negatives in perimetry
-the printout has a
clover leaf shape🍀
-SITA➡️>%15
Full-threshold➡️>%33 is highly significant
Most important defects in glaucoma occur…
Centrally-within a 30 radius from the fixation point
Prostaglandin derivatives
-‘uveoscleral’ aqueous outflow⬆️
-IOP lowering effect is greater than alternatives:
🏆1⃣st-line treatment in glaucoma (1x1 at bedtime)
✔️latanoprost (XALATAN)
🔺fewer ocular adverse effects
✔️travoprost (TRAVOPROST)
✔️bimatoprost (LUMIGAN)
🔺greater IOP-lowering effect, more conjunctival hyperemia
🔺periorbital fat loss
✔️tafluprost
Side effects (ocular) - prostaglandin derivatives
OCULAR
-conjunctival hyperaemia-common
☑️more with bimatoprost, less with tafluprost
-eyelash lengthening, thickening, hyperpigmentation
-iris hyperpigmentation-in 1/4 patients after 6 months, irreversibl
-hyperpigmentation of periocular skin-reversibl
-periorbital fat loss
☑️common with bimatoprost
-increased risk of CMO following cataract surgery when used preoperatively⚠️
-anterior uveitis, promotion of herpetic keratitis
⚠️use with caution in those patients!
Side effects (systemic) - prostaglandin derivatives
SYSTEMIC
- headache
- precipitation of migraine
- malaise
- myalgia
- skin rash
- mild upper respiratory system symptoms
Beta-blockers
-aqueous production⬇️ (mediated by an effect on the ciliary epithelium)
-tachyphylaxis in %10
-2x1
-should not be instilled on bedtime⚠️ (BP⬇️)
-preferred when: Monoocular treatment, ocular inflammation, CMO, history of HSV keratitis (❌PG❌)
✔️timolol (TIMOPTIC) - usually used in combinations
🔺non-selective➡️❌asthma, bradycardia, AV block❌
✔️betaxolol (BETOPTIC)
🔺lower hypotensive effect
🔺Ca channel blocking effect➡️optic nerve blood flow⬆️ ➡️ visual field preservation may be superior
🔺relatively cardioselective(B1)➡️less bronchoconstriction️️➡️ advantage in asthma
✔️levobunolol
✔️carteolol (CARTEOL)
🔺intrinsic sympathomimetic activity
🔺more selective on 👀 than on the cardiopulmonary system➡️less systemic side effect, advantage in bradycardia, AV block
✔️metipranolol
🔺granılomatosis anterior uveitis
Side effects (ocular) - beta blockers
OCULAR
-allergy
-punctat keratitis
-granulomatous uveitis
☑️metipranololSide effects (systemic) - beta blockers
SYSTEMIC
-bronchospasm
⚠️critical to exclude asthma before prescribing
-cardiovascular: heart block, bradycardia, worsening of heart failure, hypotension
⚠️pulse should be assessed before prescription
⚠️caution in patients with peripheral vascular disease(Reynaud)
-sleep disorders
-reduced exercise tolerance
-hallucinations
-confusion
-depression
-fatigue
-headache
-nausea, dizziness
-decreases libido
-dyslipidemiaCombined preparations
timolol ➕ ...
dorzolamide ➡️ COSOPT, OFTOMIX, DORZOTIM -2x1
brinzolamide ➡️ AZARGA -2x1
brimonidine ➡️ COMBIGAN -2x1
latanoprost ➡️ XALACOM -1x1
travoprost ➡️ DUOTRAV -1x1
bimatoprost ➡️ GANFORT -1x1
pilocarpine ➡️ TIMPILO -2x1
brimonidine ➕ brinzolamide ➡️ SIMBRINZA -2x1
Alpha-2 agonists
-aqueous production⬇️ (via an effect on the ciliary epithelium) and ‘uveoscleral’ outflow⬆️
-probably neuroprotective
-cross the blood-brain barrier➡️severe CNS depression and hypotension in young children
⚠️contraindicated
Topical carbonic anhydrase inhibitors
-aqueous secretion⬇️
-3x1 (monotherapy) or 2x1 (adjunction)
-slightly less effective than beta-blockers
-probably neuroprotective
-may precipitate corneal decompensation in patients with corneal endothelial disfunction⚠️
-some benefits in the treatment of CMO
-idiosyncratic bone marrow supression
-chemically related to sulfanomide antibiotics
⚠️relatively contrandicated in patients allergic to sulfanomides
✔️dorzolamide (TRUSOPT✖️)
✔️brinzolomide (AZOPT)
Side effects - topical carbonic anhydrase inhibitors
- stinging
- transient bitter taste following administration
- allergic blepharoconjunctivitis☑️more with dorzolamide
-a white residue may be left on the eyelids after instillation
☑️brinzolamide
Systemic carbonic anhydrase inhibitors
-aqueous secretion⬇️
-used for short-term treatment
-chemically related to sulfanomide antibiotics
⚠️relatively contrandicated in patients allergic to sulfanomides
✔️acetazolamide (DIAZOMID) -2/4x1
✔️dichlorphenamide
✔️methaxolamide
Side effects - systemic carbonic anhydrase inhibitors
OCULAR -choroidal effusion, particularly after cataract surgery -angle closure SYSTEMIC -paraesthesia -hypokalemia -malaise and lowered mood -GIS symptoms -renal stones -Stevens-Johnson syndrome (very rare) -dose-related bone marrow suppression -idiosyncratic aplastic anaemia
Miotics
-cholinergic agonists
-used in angle-closure
-opens the angle (by pulling the iris away from trabeculum) ➕ ‘trabecular’ outflow⬆️ (by contraction of the ciliary muscle)
✔️pilocarpine -4x1
🔺equal effect to beta-blockers
✔️carbachol
Side effects - miotics
LOCAL -miosis -brow ache -myopic shift -exacervation of symptoms of cataract SYSTEMIC (rare) -confusion -bradycardia -bronchospasm -GIS symptoms -urinary frequency
Osmotic agents
-creates an osmotic gradient so that water is ‘drawn out’ from the vitreous into the blood
-when a short-term reduction in IOP is required
-of limited value in inflammatory glaucoma, in which the integrity of the blood-aqueous barrier is compromised⚠️
✔️mannitol
🔺peak action occurs within 30 minutes
✔️glycerol
🔺metabolized to glucose➡️be careful in diabetics⚠️
✔️isosorbide
Side effects - osmotic agents
-CVS overload
⚠️caution in patients with cardiac or renal disease
-urinary retention
-headache
-backache
-nausea
-confusionLens-related glaucoma
PHACOLYTIC: Open angle, deep AC, intact capsule PHACOGENIC/PHACOANAPHYLACTIC: Compromised lens capsule PHACOMORPHIC: Angle closure, shallow AC
BAIT - BADI
Moxifloxacine
BAIT: iris pigment epithelium
BADI:iris stroma
Secondary-open angle-pre trabecular
Neovascular glaucoma
ICE syndrome
Epithelial ingrowth
Ocular HT-risk factors
Age IOP CCT C/D ratio PSD ————— African-American race Gender Heart disease
⚠️increased risk of RVO
POAG and NTG-risk factors
Age Race IOP Family history of POAG OD area Ocular perfusion pressure Translaminar pressure gradient Vascular disease(HT,CVD,migraine vb) DM Myopia Contraceptive pill
FOR NTG: \+Gender \+CCT \+Systemic hypotension \+OSAS \+Autoantibody levels \+Thyroid disease
PACG-risk factors
Age Gender Race Family history Refraction AL
TRAB-high risk for failure
NVG➡️➡️➡️➡️AGV Inflammatory glaucoma POS-traumatic angle recession ICE Previous failure
✳️USE MMC
NF
NF1➡️glaucoma, retinal astrocytoma
NF2➡️cataract
Wilms tumor
Aniridia (sporadic) ⚠️ ⚠️%75 risk of glaucoma
Peters anomaly
Bilateral
⚠️%50 risk of glaucoma
Central corneal opacity
Posterior corneal defect-iridocorneal or lenticulocorneal adhesions
Axenfeld Rieger syndrome
Bilateral
⚠️%50 risk of glaucoma
Axenfeld anomaly: posterior embryotoxon, attached strands of peripheral iris
Rieger anomaly: posterior embryotoxon, iris stromal hypoplasia, ectropion uveae, corectopia, full-thickness iris defects
Rieger syndrome: dental anomalies, facial anomalies, redundant paraumblical skin, hypospadias
Malignant glaucoma
High IOP, shallow AC, absent bleb, negative Seidel
Treatment: Atropine
Pupillary block
High IOP, shallow AC, flat bleb, negative Seidel, iris bombe
Treatment: LPI
Inflammatory glaucomas
FUS-%60 JIA Herpes Zoster-Simplex Toxoplasma Posner-Schlossman
Ciliary body shutdown, steroid responders, CLOSE: angle closure with/without pupillary block, OPEN: trabecular obstruction, acute trabeculitis, trabecular scarring
