5. Secondary Glaucoma

Pseudoexfoliation Syndrome (PXF, PEX)

• Pseudoexfoliative material (PXM) from abnormal basement membrane of aging cells in the anterior segment

• Affected structures: lens, zonules, iris, ciliary body (CB), trabecular meshwork (TM)

• PXM deposits in the TM block aqueous outflow → pseudoexfoliative glaucoma

• More common in females : male ratio (2:1)

• Classified as a secondary glaucoma when outflow is impeded by PXM

Pseudoexfoliation (clinical signs on anterior segment)

• PXM on the anterior lens surface with a clear ring at the pupil- lens contact zone; rubbing off PXM

• PXM and pigment may be visible on the corneal endothelium → can mimic keratic precipitates (KP)

• PXM and clumps of pigment seen on the posterior TM with gonioscopy and at Schwalbe's line (Sampaolesi's line)

  
  

  

Pigment Dispersion Syndrome (PDS)

• Pigment from posterior iris is lost due to mechanical rubbing of the iris on the zonules caused by the iris curvature

• Pigment deposits in the TM, blocking aqueous outflow → pigmentary glaucoma

• About $30\%$ of patients with PDS develop glaucoma

• More common in males (ratio ≈ $5:1$)

• Associated with myopia: deep anterior chamber (AC) and convex curvature of the iris

• Typically presents in individuals in the mid-30s or older

Pigment dispersion signs (PDS)

• Pigment deposition on the corneal endothelium, usually in a vertical band centrally (Krukenberg spindle)

• Peripheral iris transillumination with slit-like defects

• Pigment dusting on the peripheral iris

• Heavy pigment seen on the posterior TM on gonioscopy

Figure reference (Pigment Dispersion)

• (a) Krukenberg spindle; (b) pigment granules on iris surface and partial loss of the pupillary ruff; (c) radial slit-like transillumination defects; (d) homogeneous trabecular hyperpigmentation

Rubeosis Iridis

• Neovascularization of the iris and angle → neovascular glaucoma (secondary open-angle glaucoma; can be closed-angle if fibrovascular tissue contracts, causing anterior synechiae)

• Common causes:

  • diabetes mellitus (proliferative diabetic retinopathy)

  • central retinal vein occlusion (100-day glaucoma)

  • any retinal ischemia leading to neovascular response

• Management: refer promptly; treat the underlying cause (e.g., panretinal photocoagulation, PRP) and manage the glaucoma

• Vessels proliferate in the angle to form a fibrovascular membrane → trabecular blockage

• Fibrovascular membrane may contract and pull the peripheral iris over the TM → progressive angle closure

Inflammation of the anterior segment (uveitis) and glaucoma

• Cells and flare in uveitis may lead to inflammatory/uveitic glaucoma

• Two mechanisms: with pupil block and without pupil block

With pupil block

• Angle-closure glaucoma with pupil block: inflammatory adhesion (posterior synechiae) at the pupil margin causes pupil block

• Iris bombe can occur, leading to angle closure

Without pupil block

• Closed-angle glaucoma: inflammatory cells/flare cause peripheral iris sticking to TM and cornea (anterior synechiae) closing the angle

• Open-angle glaucoma: inflammatory material in the anterior chamber may block TM, causing rise in IOP

• IOP often falls as inflammation subsides

Peripheral anterior synechiae (PAS)

• Abnormal adhesions between the iris and cornea or TM contributing to angle closure risk

Fuchs’ heterochromic iridocyclitis (Fuchs’ uveitis)

• Idiopathic, unilateral (≈90%), chronic uveitis

• Often resistant to steroids

• Common complication: cataract; glaucoma in about $30\%$ of patients

• Rare overall: accounts for about $1-3\%$ of all uveitis cases

• Typically diagnosed in the 30s–40s

Additional signs

• Affected eye shows lighter, paler iris and iris atrophy

• Cataract formation

• HOODD (presentation on slides; not a diagnostic criterion here)

Posner-Schlossman syndrome ( glaucomatocyclitis)

• Recurrent attacks of unilateral acute iritis with secondary open-angle glaucoma

• The eye often appears relatively white; open angle on gonioscopy

• Aqueous shows few cells with fine central keratic precipitates (KP)

• Elevated IOP thought to be from trabeculitis

• Typical age range: $20-50\text{ years}$

• IOP elevation lasts for hours to days

• Symptoms: mild discomfort, halos, slight blur; corneal edema

• IOP can reach $40-80\,\text{mmHg}$ during attacks

Phacolytic glaucoma (lysis/burst of lens capsule)

• Occurs with mature or hypermature cataract

• Soluble lens proteins leak through the capsule and obstruct TM

• Acute IOP elevation

• Redness, pain, intense aqueous flare

• White particles in aqueous humor; macrophages loaded with lens protein

• Classic example of lens-induced glaucoma

Phacomorphic glaucoma (morphology/shape)

• Acute secondary angle closure due to lens enlargement (intumescent lens)

• Mechanisms:

  • Pupillary block

  • Lens pushing the iris forward

• Both cause irido-corneal contact and angle closure

Acute secondary angle closure • Caused by intumescent (expanding) lens

Traumatic glaucoma

• Hyphema: blockage of TM by red blood cells

• Angle recession: rupture of the inner circular/facial aspect of ciliary body between iris root and scleral spur due to blunt trauma

  • Rise in IOP secondary to trabecular damage Glaucoma may develop months or years later Gonioscopy

• Iridodialysis: iris separation from ciliary body

  • Rise in IOP secondary to trabecular damage Glaucoma may develop months or years later Gonioscop

Management and treatment notes (post-traumatic and steroid-related)

• Steroid-related pathways require monitoring of intraocular pressure (IOP) for hyphaema

• IOP-lowering medications may be used for non-inflammatory glaucoma management while addressing the inflammation

• Gonioscopy should be performed after blood clears

Iridocorneal Endothelial (ICE) syndrome

• ICE is a group of three overlapping disorders:

  • Progressive iris atrophy

  • Iris nevus (Cogan-Reese) syndrome

  • Chandler syndrome

• Characterized by abnormal corneal endothelium that proliferates and migrates across the angle to the iris

• Can cause corneal decompensation and glaucoma (angle-closure due to synechiae) or open-angle glaucoma

• Believed to have a viral association

• Differential diagnosis includes Axenfeld anomaly (autosomal dominant, bilateral)

ICE signs

• Typically unilateral in middle-aged women

• Corectopia (displaced pupil)

• Pseudopolycoria (false extra pupils)

• Iris atrophy

• Corneal endothelial abnormalities with a hammered-silver appearance

• Broad peripheral anterior synechiae extending to Schwalte’s line

• Glaucoma develops in about $50\%$ of cases

Sturge-Weber Syndrome

• Port-wine stain (naevus flammeus) of the face, following the distribution of the trigeminal nerve

• Ocular involvement: conjunctival, episcleral, and choroidal haemangiomas

• Glaucoma more common when lids and conjunctiva are involved (≈ $30\%$)

  • Mechanism unknown:

  • in children, raised IOP may be due to malformation of the trabecular meshwork

  • in adults, raised episcleral venous pressure contributes

• Glaucoma in Sturge-Weber: reduced aqueous outflow through episcleral veins due to the haemangioma

Carotid-Cavernous Fistula

• Fistula = abnormal communication between an artery and a vein

• Blood within the venous system becomes arterialised; venous pressure rises, drainage altered

• Communication between the carotid artery and the cavernous sinus

• Arterial blood enters the sinus; venous blood cannot drain effectively

• Glaucoma from raised episcleral venous pressure (EVP)

Types

• Direct: carotid artery flows directly to cavernous sinus through a defect in the wall of the intracavernous section

  • often high-flow

  • commonly trauma-related or spontaneous rupture of a intracavernous aneurysm or atherosclerotic artery

• Indirect: intracavernous carotid is intact

  • arterial blood reaches cavernous sinus via meningeal branches of external or internal carotids

  • slower flow

  • congenital malformations or spontaneous rupture

Fistula - Imaging and management notes

• Management can include imaging (e.g., MRI) and endovascular intervention (e.g., coil embolization) for fistulas

• Example: MRI of brain/orbits with endovascular coiling to occlude the fistula and rapid clinical improvement

Intraocular tumours and angle-related pathologies

• Intraocular tumours can involve the iris or ciliary body or anything affecting the anterior chamber angle

Case example (scan data)

• 70-year-old female with sore eye for 10 weeks; VA R = 6/7.5, L = 6/6; IOP: R = 39 mmHg, L = 12 mmHg

Steroid-induced glaucoma and routes of administration

• Steroid-induced glaucoma: elevated IOP due to increased outflow resistance from steroids

  • Upregulation of glucocorticoid receptors in trabecular meshwork

  • suppression of phagocytic activity → deposition of material in the angle

• Risk increases with duration and dose (penetration of tissue)

• IOP rise typically occurs 2–4 weeks after starting steroids

• Management: cease steroid if possible; consider non-steroidal anti-inflammatory alternatives; initiate glaucoma therapy when needed

Steroid routes and their implications

• Topical ocular preparations: drops or ointment applied to the eye/eyelids

• Periocular: subconjunctival, sub-Tenon’s, or retrobulbar injections

• Intravitreal: about $50\%$ of patients develop an IOP spike within 2–4 weeks

• Dermatologic: steroids applied to the skin around the eyelids (long-term use)

• Systemic: oral steroids; rare, may include inhaled or nasal steroids