Secondary Glaucomas

Secondary glaucomas are a heterogeneous group in which a definable ocular or systemic disorder raises intraocular pressure (IOP), unlike primary glaucomas where no antecedent cause is found. For NEET PG, the magic lies in pattern recognition: each entity carries a near-pathognomonic gonioscopic and slit-lamp signature, so a single clue (a Krukenberg spindle, glaukomflecken, a recessed angle, NVI) usually nails the answer.

Definition & classification

A secondary glaucoma is optic neuropathy with characteristic field loss caused by IOP elevation that is attributable to an identifiable pathology. The most useful classification is by the mechanism at the angle, because management flows directly from it.

Mechanism	Angle on gonioscopy	Representative entities
Secondary open-angle	Open	Pseudoexfoliation, pigmentary, steroid-induced, lens-particle, ghost-cell, angle-recession, uveitic (open phase)
Secondary angle-closure WITH pupillary block	Closed	Phacomorphic, posterior synechiae/seclusio pupillae, intumescent lens
Secondary angle-closure WITHOUT pupillary block (anterior pull)	Closed by membrane/synechiae	Neovascular glaucoma, ICE syndrome, epithelial downgrowth
Secondary angle-closure (posterior push)	Shallow AC, forward lens-iris	Malignant (aqueous misdirection) glaucoma, ciliary block, posterior segment tumour

High-yield: The single most discriminating tool in secondary glaucoma is gonioscopy. Open angle + heavy pigment = pigmentary/PXF; closed angle + new vessels = neovascular; angle "torn" with widened ciliary band = angle-recession.

Neovascular glaucoma (NVG)

NVG is the prototype of secondary angle closure without pupillary block. It is the most heavily tested secondary glaucoma because of its tight link to ischaemic retinal disease.

Etiology & pathophysiology

Retinal ischaemia → upregulation of VEGF → diffusion of VEGF into the anterior segment → new vessels grow on the iris (rubeosis iridis / NVI) and across the trabecular meshwork (NVA). Initially the angle is open but obstructed by the fibrovascular membrane (secondary OPEN-angle phase). The fibrovascular membrane then contracts, dragging the peripheral iris over the meshwork to form peripheral anterior synechiae (PAS) and pulling the pupil → ectropion uveae, producing secondary closed-angle glaucoma.

The classic causes, in descending frequency:

1. Ischaemic central retinal vein occlusion (CRVO) — "90-day glaucoma" because NVG typically appears ~3 months after an ischaemic CRVO.
2. Proliferative diabetic retinopathy (PDR).
3. Ocular ischaemic syndrome (carotid occlusive disease).

High-yield: Ischaemic CRVO → 90-day (100-day) glaucoma. Always examine the undilated iris and angle FIRST in a CRVO/PDR patient because early NVI is best seen at the pupillary margin before dilation distorts it.

Clinical features

• Stages: (1) rubeosis iridis (fine tufts at pupil margin & angle, IOP normal) → (2) secondary open-angle glaucoma (membrane over open angle, high IOP) → (3) secondary closed-angle glaucoma (PAS, ectropion uveae, "zippering" of the angle).
• Painful red eye, very high IOP (often 40–60 mmHg), corneal oedema, ciliary flush, poor vision.

Investigations & management

Investigation of choice for the underlying ischaemia is fundus fluorescein angiography (FFA) showing capillary non-perfusion; carotid Doppler if ocular ischaemic syndrome is suspected.

Management flow:

Reduce VEGF & ischaemia → control IOP → treat retina definitively

1. Intravitreal anti-VEGF (bevacizumab/ranibizumab) — rapid regression of NVI, a temporising bridge.
2. Pan-retinal photocoagulation (PRP) — the definitive treatment that removes the ischaemic VEGF-producing stimulus.
3. IOP control: aqueous suppressants (timolol, brimonidine, dorzolamide, oral acetazolamide). Avoid pilocarpine and prostaglandin analogues (worsen inflammation/congestion).
4. Refractory IOP → glaucoma drainage device (Ahmed valve) preferred over trabeculectomy (high failure from fibrovascular tissue); diode cyclophotocoagulation for blind painful eyes; retrobulbar alcohol/enucleation as last resort.

High-yield: In NVG, the definitive treatment of the cause is PRP; anti-VEGF gives rapid but temporary regression. Trabeculectomy fails — choose a drainage implant.

Pigment dispersion syndrome (PDS) & pigmentary glaucoma

A secondary open-angle glaucoma of young, myopic males.

Pathophysiology

A concave peripheral iris rubs against the lens zonules ("reverse pupillary block") → liberation of pigment from the iris pigment epithelium → pigment clogs the trabecular meshwork → raised IOP.

Triad of signs

Sign	Description
Krukenberg spindle	Vertical fusiform deposit of pigment on the corneal endothelium
Iris transillumination defects	Radial mid-peripheral spoke-like defects (slit-beam retroillumination)
Heavy trabecular pigmentation	Dense homogeneous pigment band (often with Sampaolesi line — pigment anterior to Schwalbe's line)

High-yield: A young myopic man + Krukenberg spindle + mid-peripheral spoke-like iris transillumination = pigmentary glaucoma. Exercise / pupillary dilation can trigger pigment showers and acute IOP spikes.

Mnemonic for the triad: "KIT" — Krukenberg spindle, Iris transillumination defects, Trabecular hyperpigmentation.

Management: standard medical therapy; laser peripheral iridotomy can flatten the concave iris and reduce iris-zonule chafing; selective laser trabeculoplasty works well because of the pigmented meshwork (use low energy to avoid IOP spikes).

Pseudoexfoliation glaucoma (PXF / PEX)

The commonest identifiable cause of secondary open-angle glaucoma worldwide, classically in elderly patients (Scandinavian and Indian populations heavily represented).

Pathophysiology

A systemic fibrillar basement-membrane / elastotic material (with LOXL1 gene association) is deposited on anterior segment structures and clogs the trabecular meshwork. It is a systemic disorder (deposits in lung, heart, kidney vessels) but ocular consequences dominate.

Signs

• Classic target/bull's-eye pattern of greyish-white flaky material on the anterior lens capsule: a central disc + clear intermediate zone + peripheral granular band (created by iris movement wiping the mid-zone).
• Deposits on pupillary margin ("dandruff"), poor pupillary dilation.
• Heavy, patchy trabecular pigmentation with a Sampaolesi line.
• Weak zonules / phacodonesis → high risk of zonular dehiscence and lens subluxation during cataract surgery.

High-yield: PXF is the most important systemic association in glaucoma surgery counselling — expect zonular weakness, poor dilation and capsular instability during cataract surgery (highest risk of vitreous loss and dropped nucleus). PXF glaucoma is more aggressive and harder to control than POAG.

Compare the two pigment-deposition glaucomas:

Feature	Pigmentary glaucoma	Pseudoexfoliation glaucoma
Typical patient	Young, myopic male	Elderly, either sex
Material	Iris pigment epithelium	Fibrillar exfoliative material (LOXL1)
Cornea	Krukenberg spindle	—
Lens	—	Target deposits on anterior capsule
Iris	Mid-peripheral transillumination defects	Peripupillary defects, "moth-eaten"
Pigment line	Sampaolesi line ±	Sampaolesi line (prominent)
Surgical caveat	—	Weak zonules, poor dilation

Steroid-induced glaucoma

A secondary open-angle glaucoma caused by corticosteroid exposure (topical >> periocular > systemic; inhaled and dermatological routes also reported).

Pathophysiology

Steroids increase deposition of glycosaminoglycans and decrease degradation of extracellular matrix in the trabecular meshwork → increased outflow resistance. Roughly one-third of the population are "steroid responders" (≈18 mmHg rise) and a smaller fraction are high responders (>15 mmHg rise). Onset is typically 2–6 weeks after starting potent topical steroids.

High-yield: A child on topical steroids for vernal keratoconjunctivitis (VKC) who develops raised IOP is the classic steroid-induced glaucoma vignette. Dexamethasone and betamethasone are the highest-risk; fluorometholone, loteprednol and rimexolone are "soft" steroids with lower IOP effect.

Management: stop or switch the steroid — IOP usually normalises within weeks; bridge with aqueous suppressants; rarely needs surgery if the angle has been damaged by prolonged use.

Angle-recession glaucoma (traumatic)

Follows blunt ocular trauma (classically a cricket/squash ball, bungee cord, or fist). A compressive force tears the face of the ciliary body between the longitudinal and circular muscle fibres.

Mechanism & signs

• Gonioscopy shows an irregularly widened ciliary body band, torn iris processes, and a recessed angle compared with the fellow eye.
• Glaucoma can be early (trabecular damage / associated hyphaema) or late (months–years later from trabecular scarring) — long-term follow-up is mandatory.
• Often unilateral; compare the two eyes on gonioscopy.

High-yield: Recession of more than 180–270° of the angle markedly raises the lifetime risk of glaucoma. Any patient with prior blunt trauma needs lifelong IOP surveillance even after the eye looks quiet.

Related post-traumatic mechanisms to distinguish: hyphaema (RBCs block meshwork acutely), ghost-cell glaucoma (degenerated khaki-coloured RBCs from a vitreous haemorrhage clog the meshwork weeks later), and haemolytic glaucoma (macrophages laden with blood products).

Lens-induced (phacogenic) glaucomas

A favourite NEET comparison set — distinguish open vs closed mechanisms:

Type	Mechanism	Lens status	Angle
Phacomorphic	Intumescent (swollen) cataract pushes iris forward → pupillary block	Mature/intumescent	Closed
Phacolytic	Leaked high-MW lens proteins + macrophages clog meshwork	Hypermature (Morgagnian)	Open
Phacoantigenic (lens-induced uveitis)	Granulomatous immune reaction to retained cortex	Post-trauma/post-surgery retained lens matter	Open
Lens particle	Free cortical particles physically block meshwork	After trauma/surgery	Open

High-yield: Phacolytic glaucoma = hypermature cataract + open angle + heavy flare + floating macrophages; aqueous tap shows swollen macrophages laden with lens material. Treatment is urgent cataract extraction, not just IOP drops.

Uveitic glaucoma

Inflammation raises IOP by several simultaneous mechanisms: trabeculitis and inflammatory debris (open-angle), posterior synechiae → seclusio pupillae → iris bombé (pupillary-block closed-angle), PAS formation, and steroid response from treatment. The classic eponym is Posner-Schlossman syndrome (glaucomatocyclitic crisis) — recurrent unilateral attacks of markedly raised IOP with mild anterior uveitis and an open angle, often linked to CMV. Fuchs heterochromic iridocyclitis also causes open-angle glaucoma with characteristic fine stellate KPs and iris heterochromia.

ICE syndrome & developmental note

Iridocorneal endothelial (ICE) syndrome is a unilateral disorder of abnormal "ICE cells" (proliferating corneal endothelium) migrating across the angle and iris, producing PAS, corectopia, iris atrophy and a hammered-silver / beaten-bronze corneal endothelial appearance on specular microscopy. Its three overlapping variants — Chandler syndrome (most common, corneal oedema dominant), progressive (essential) iris atrophy (iris holes, marked corectopia), and Cogan-Reese (iris naevus) syndrome (pigmented iris nodules) — are classic one-liners.

High-yield: ICE syndrome is unilateral, in young-to-middle-aged women, with corneal endothelial abnormality + corectopia + secondary angle closure. Differentiate from posterior polymorphous dystrophy (bilateral, AD).

Malignant (aqueous misdirection) glaucoma

A posterior-push secondary angle closure where aqueous is misdirected posteriorly into/behind the vitreous, pushing the lens-iris diaphragm forward → uniformly shallow central AND peripheral anterior chamber with high IOP, classically after intraocular surgery in a small hyperopic eye. Crucially it does not respond to (and is worsened by) miotics; treatment is cycloplegics (atropine) + aqueous suppressants + hyperosmotics, then laser/vitrectomy.

Key differentials at a glance

Decision flow when you see high IOP: Gonioscopy → angle open? → look for pigment (pigmentary/PXF), new vessels (early NVG), flare/macrophages (phacolytic), steroid history. Angle closed? → new vessels + ectropion uveae (NVG late), iris bombé (uveitic/pupillary block), shallow uniform AC post-op (malignant glaucoma), beaten-bronze endothelium + corectopia (ICE).

Clue	Diagnosis
Krukenberg spindle, young myope	Pigmentary glaucoma
Target deposits on lens, poor dilation, elderly	Pseudoexfoliation
New vessels on iris + ischaemic CRVO/PDR	Neovascular glaucoma
Recent blunt trauma, widened ciliary band	Angle-recession glaucoma
Child with VKC on steroids	Steroid-induced glaucoma
Hypermature cataract + open angle + macrophages	Phacolytic glaucoma
Beaten-bronze endothelium + corectopia, unilateral woman	ICE syndrome
Shallow AC + high IOP post-op, worsens with miotics	Malignant glaucoma

Recently asked / exam angle

• Ischaemic CRVO → neovascular glaucoma at ~90–100 days; FFA shows capillary non-perfusion; PRP is definitive, anti-VEGF is a bridge — repeatedly tested cause-and-treatment pairing.
• Drug to AVOID in NVG: pilocarpine/miotics and prostaglandin analogues (inflammation); preferred surgery is a drainage implant, not trabeculectomy.
• Pseudoexfoliation surgical pearl: weak zonules + poor dilation → highest risk of zonular dialysis/vitreous loss during phaco; LOXL1 gene association.
• Pigmentary glaucoma: identify the Krukenberg spindle image and the young myopic male; mechanism is reverse pupillary block.
• Steroid responder physiology (≈1/3 of population) and the soft steroids (FML, loteprednol) that minimise IOP rise.
• Angle-recession recognised on gonioscopy by a torn, widened ciliary body band; needs lifelong follow-up.
• Phacolytic vs phacomorphic distinction (open vs closed angle) is a recurring one-mark differentiator.
• Posner-Schlossman syndrome (open-angle, recurrent, CMV-linked) and Fuchs heterochromic iridocyclitis as uveitic open-angle causes.
• Malignant glaucoma: uniformly shallow AC, worsens with miotics, treat with atropine — a classic "which drug is contraindicated" question.

Rapid revision

1. Gonioscopy is the single most discriminating investigation in any secondary glaucoma.
2. Ischaemic CRVO causes neovascular glaucoma at about 90 days ("90-day glaucoma").
3. NVG: anti-VEGF for rapid regression, PRP is definitive, Ahmed valve if surgery is needed.
4. Avoid pilocarpine and prostaglandins in neovascular glaucoma.
5. Pigmentary glaucoma triad = Krukenberg spindle + iris transillumination defects + heavy trabecular pigment in a young myopic male.
6. Pseudoexfoliation = elderly, target deposits on anterior lens capsule, poor dilation, weak zonules (surgical caution), LOXL1 gene.
7. Sampaolesi line (pigment anterior to Schwalbe's line) is seen in both pigmentary and pseudoexfoliation glaucoma.
8. Steroid-induced glaucoma classically follows topical steroids for VKC; fluorometholone/loteprednol are low-risk soft steroids.
9. Angle-recession glaucoma: prior blunt trauma, widened ciliary body band; lifelong IOP follow-up needed.
10. Phacolytic = hypermature cataract, open angle, macrophages; phacomorphic = intumescent lens, closed angle (pupillary block).
11. ICE syndrome: unilateral, young woman, beaten-bronze endothelium + corectopia + secondary angle closure.
12. Malignant glaucoma: uniformly shallow AC, high IOP, worsens with miotics — treat with atropine + aqueous suppressants.