When diagnosing glaucoma, the first step is to distinguish between open-angle and angle-closure glaucoma. This can be differentiated by slit-lamp examination and gonioscopy.
If an open anterior chamber angle is found, a distinction must be made between primary (POAG) and secondary open-angle glaucoma (SOAG). The following distinct characteristics are causative of SOAG:
- Inflammatory reaction
- Angle configuration
- Iris configuration
- Involvement of the lens/IOL/postoperative status
In all cases, work-up should proceed as for primary open-angle glaucoma; additional investigations may be necessary.
Summary of the Distinguishing Features of the Most Common SOAG
Angle Recession Glaucoma
- Unilateral, after trauma (after several years)
- Diagnostics
- Gonioscopy: irregular iris insertion, recession
- Therapy: as for POAG, no ALT/SLT, no miotics, trabeculectomy/deep sclerectomy if applicable
- Management: as for POAG
Inflammatory OAG
- Anterior chamber cells, KP, injection, posterior synechiae, increased pigmentation of the trabecular meshwork (mainly inferior) -> possible angle closure
- Diagnostics: as for POAG, plus uveitis work-up (caution: consider herpes)
- Therapy
- Prednisolone eye drops (e.g. Pred Forte) hourly to every 6 hours, cycloplegics (Cyclogyl 0.5% 6x/day)
- As for POAG (no prostaglandin analogues, no laser), trabeculectomy/tube shunt if applicable
- Management
- Daily follow-up until inflammation and pressure spike have normalized, extend follow-up intervals thereafter
- Taper prednisolone eye drops, then taper pressure-lowering therapy
Posner-Schlossman Syndrome/Glaucomatocyclitic Crisis
- Unilateral, 40-60 mmHg, few anterior chamber cells
- Diagnostics: as for POAG, corneal edema, minimal injection, small hypochromic iris, fine KPs on the cornea and trabecular meshwork, synechiae
- Therapy/management: as for inflammatory OAG, NSAID if applicable
Steroid-Response Glaucoma
- Typically 2-4 weeks after steroid application (any route)
- History: medication history, eye surgery, family history, trauma, high myopia, African ancestry (predisposition for glaucoma)
- Diagnostics: as for POAG
- Therapy: taper or switch steroid therapy, as for POAG, after intravitreal steroid application vitrectomy if applicable
- caution: in patients with prior LASIK -> interface fluid syndrome, measure tonometry outside the flap or by palpation
- Management: as for inflammatory OAG
Pigment Dispersion Glaucoma
- Ae: posterior bowing of the peripheral iris -> friction against the zonular fibers -> release of pigment -> obstruction of the trabecular meshwork
- E: younger patients (20-45 years), bilateral asymmetric, coincidence with lattice degeneration (retinal detachment)
- History: eye surgery, trauma, intraocular foreign body
- Diagnostics: as for POAG, Krukenberg spindle, pigment on the anterior lens surface, Sampaolesi's line, hyperpigmented trabecular meshwork, peripheral retina under mydriasis
- Therapy: miotics (Spersacarpine 2%) 4x/day, as for POAG, LPI if applicable, deep sclerectomy if applicable
Pseudoexfoliation Syndrome/Glaucoma (PEX)
- Ae: exfoliation material -> obstruction of the trabecular meshwork
- E: most common secondary OAG in Europe, bilateral, asymmetric
- Prognosis: 25% develop glaucoma, difficult to treat
- Diagnostics: PEX material, Sampaolesi's line, iris atrophy, reduced pupillary motility, zonular weakness (phacodonesis) -> angle closure
- Therapy: as for POAG, SLT particularly effective
- Management: initially every 1-3 months, then every 6 months (even without existing glaucomatous damage)
Phacolytic Glaucoma
- Ae: leakage of lens material (liquefied, mature or hypermature) through an intact lens capsule -> obstruction of the trabecular meshwork
- Therapy: as for POAG (no prostaglandin analogues), prednisolone eye drops (hourly up to 6x/day) -> emergency cataract surgery if applicable
- Management: if IOP and inflammation are controllable medically -> prompt cataract surgery, close follow-up until then
Lens Particle Glaucoma
- Diagnosis: anterior chamber with white, fluffy lens particles after cataract surgery or trauma
- Therapy: if IOP and inflammation are medically treatable -> prompt cataract surgery with close follow-up, otherwise emergency anterior chamber washout
Phacoantigenic Uveitis/Glaucoma (formerly Phacoanaphylaxis)
- Ae: sensitization of the immune system after release of lens material by cataract surgery or trauma -> chronic granulomatous uveitis
- DD: sympathetic endophthalmitis
- Diagnosis: granulomatous anterior chamber with lens material and inflammatory cells
- Therapy: as for lens particle glaucoma
Phacomorphic Glaucoma
- Angle closure or possible pupillary block due to a large intumescent cataract
- Therapy: LPI can temporarily relieve pupillary block -> definitive treatment only by cataract surgery
Glaucoma due to Lens Dislocation/Subluxation
- Ae: trauma/PEX/congenital zonular dysgenesis (e.g. Marfan syndrome) -> inflammatory reaction, pupillary block, or damage to the angle
- Therapy: as for inflammatory OAG -> surgical removal of the lens
Glaucoma due to Lens Dislocation/Subluxation
- Ae: trauma/PEX/congenital zonular dysgenesis (e.g. Marfan syndrome) -> inflammatory reaction, pupillary block, or damage to the angle
- Therapy: as for inflammatory OAG -> surgical removal of the lens
Plateau Iris
- Ae: anatomy of the peripheral iris bowed anteriorly -> transient angle closures
- Plateau iris configuration: recurrent episodes of angle closure -> LPI can prevent pupillary block (not curative)
- Plateau iris syndrome: peripheral iris and ciliary body bow forward and close the angle, e.g. after dilation (without pupillary block)
- Therapy
- In an existing acute angle-closure situation: as for angle-closure glaucoma with LPI, gonioscopy after 1 week, then mydriasis with tropicamide 0.5% (Mydriaticum Dispersa 0.5%); if IOP rises or angle closure develops -> diagnosis: plateau iris syndrome -> miotic eye drops (Spersacarpine 2%) 2x/day until laser iridoplasty
- without acute angle-closure situation: LPI, gonioscopy follow-up every 4-6 months -> if anterior synechiae form or the angle progressively narrows -> iridoplasty -> if no improvement, cataract surgery if applicable
- Management: follow-up as for POAG, screening of family members if applicable
Neovascular Glaucoma
- Ischemia (DM, retinal vein/artery occlusion, ocular ischemic syndrome/chronic uveitis/intraocular tumors) -> neovascularization in the angle (rarely limited to the angle alone) (Stage 1), fibrovascular membrane closes the angle -> IOP elevation (Stage 2), can contract and cause secondary angle closure (Stage 3)
- Diagnostics: identify the cause, fluorescein angiography; if the retina is unremarkable -> ultrasound of the carotid arteries
- Therapy: as for inflammatory glaucoma (no miotics), paracentesis if applicable
- for retinal ischemia: PRP of ischemic areas, intravitreal anti-VEGF
- for uncontrollable IOP: trabeculectomy/tube shunt
- for poor visual prognosis: Pred Forte eye drops 4x/day and Cyclogyl eye drops 3x/day for pain control, cyclophotocoagulation if applicable
Iridocorneal Endothelial Syndrome
- Ae: abnormal corneal endothelium grows over the angle (essential iris atrophy, Chandler syndrome, Cogan-Reese syndrome) -> contraction of this endothelial membrane -> secondary angle closure
- Therapy: as for POAG, trabeculectomy/tube shunt if applicable (no deep sclerectomy/stents/LPI/SLT)
Postoperative Glaucoma
Early postoperative IOP elevation
- IOP elevation typically occurs 1 hour after cataract surgery and normalizes within 1 week
- Ae: retained viscoelastic, retained lens/cortical fragments, pupillary block, hyphema, pigment dispersion, inflammatory reaction
- Therapy:
- Eyes without glaucomatous damage > 30 mmHg
- Eyes with existing glaucomatous damage > 21 mmHg
- Cosopt 2x/day, Alphagan 2x/day, Diamox 250 mg tablet up to 4x/day if applicable with potassium chloride tablets 1x/day
- Pred Forte eye drops every 2 hours
Postoperative pupillary block
- Diagnostics: shallow anterior chamber with iris bombé, no LPI, elevated IOP, adhesions of the posterior iris to the IOL/lens capsule
- Therapy: LPI; if not possible: mydriatics, Cosopt eye drops, Alphagan eye drops up to 3x at 15-minute intervals if applicable, Pred Forte eye drops 4x/day
- Diamox 250 mg tablet 4x/day with potassium tablet 1x/day
- LPI or surgical iridectomy if applicable
- trabeculectomy/deep sclerectomy if applicable
Uveitis-Glaucoma-Hyphema Syndrome (UGH Syndrome)
- Ae: malposition of a posterior/anterior chamber IOL with iris contact and chafing
- Diagnostics: slit lamp: anterior chamber cells, hyphema, elevated IOP
- Therapy:
- Atropine 1% 2x/day, prednisolone eye drops 4-8x/day, NSAID if applicable,
- Cosopt eye drops 2x/day, Diamox 250 mg 4x/day if applicable
- Argon laser photocoagulation of the bleeding site
- for recurrent episodes, surgical repositioning or removal of the IOL if applicable
Malignant Glaucoma
Ae: anterior rotation of the ciliary body, possibly due to choroidal expansion -> aqueous humor is misdirected posteriorly -> backflow into the vitreous cavity -> the lens is pushed anteriorly -> secondary pupillary block
- Diagnostics: slit lamp: diffuse shallowing of the anterior chamber (no iris bombé, existing LPI if applicable), Seidel test, mildly to moderately elevated IOP, ultrasound (choroidal detachment, intraocular hemorrhage)
- Therapy: as for POAG, plus atropine 1% and phenylephrine 2.5% (no miotics) -> if not resolved, LPI -> in pseudophakia/aphakia, disruption of the posterior capsule and anterior hyaloid with YAG
- for choroidal detachment: sclerectomy for drainage (tertiary center)
- PPV with irido-zonulo-hyaloidectomy with excision of the iris, lens capsule (tertiary center)
