Glaucoma Management

Causes and Risk Factors

Closed-angle glaucoma is primarily caused by pupillary block, where pressure in the posterior chamber exceeds that in the anterior chamber, causing anterior bowing of the iris that crowds the angle in anatomically predisposed eyes 1
Ocular features that increase risk include hyperopia, shallow anterior chamber depth, steep corneal curvature, thick crystalline lens, short axial length, and anterior lens position, as well as ciliary body position and iris insertion, such as anterior rotation of ciliary body and abnormal iris insertion into ciliary body 1, 2
Risk factors for narrow angle glaucoma include Asian descent, hyperopia (farsightedness), older age (typically >50 years), female gender, short axial length, thick and anteriorly positioned crystalline lens, steep corneal curvature, and family history of angle closure 1, 2

Primary angle-closure suspect is defined as ≥180° of iridotrabeccular contact (ITC) 1
Primary angle closure occurs when ITC is accompanied by elevated intraocular pressure (IOP) and/or development of peripheral anterior synechiae (PAS) 1, 2
Primary angle-closure glaucoma develops when glaucomatous optic neuropathy occurs due to sustained or intermittent IOP elevation 1
The modern classification of primary angle-closure disease includes primary angle-closure suspect (PACS), primary angle closure (PAC), primary angle-closure glaucoma (PACG), acute angle-closure crisis (AACC), and plateau iris configuration/syndrome 1, 2

Acute angle-closure crisis (AACC) occurs when sudden complete angle obstruction causes rapid IOP elevation, presenting with corneal edema, mid-dilated pupil, eye pain, headache, nausea/vomiting 1
Symptoms of AACC include eye pain, blurred vision, halos around lights, headache, nausea/vomiting, eye redness, and a mid-dilated pupil, particularly during an acute angle-closure crisis (AACC) 1, 2
Immediate treatment is essential to prevent permanent vision loss, and may include medical therapy to rapidly lower IOP, such as systemic carbonic anhydrase inhibitors, topical beta-blockers, alpha-2 agonists, and prostaglandin analogs, as well as definitive treatment with laser peripheral iridotomy (LPI) or surgical iridectomy once IOP is controlled 1, 2, 3
Lens extraction may be effective for some PAC and PACG patients, particularly in refractory cases 1

Higher prevalence of angle closure is found in Asian populations, women, older adults, and those with a family history of angle closure 1
Without treatment, AACC can cause permanent vision loss or blindness, with a 18% blindness rate and 48% developing glaucomatous optic neuropathy 1
Without treatment, the prognosis for AACC is poor, with 18% of eyes becoming blind, 48% developing glaucomatous optic neuropathy, and 58% having visual acuity worse than 20/40 within 4-10 years following an AACC 2

Management focuses on prevention of progression, and may include laser peripheral iridotomy, IOP-lowering medications, and lens extraction in appropriate cases 1, 2
After an episode of AACC, careful monitoring is essential, including regular IOP monitoring, gonioscopy to verify improvement in angle configuration, and assessment for glaucomatous optic neuropathy 1, 2
The American Academy of Ophthalmology recommends follow-up intervals based on target IOP achievement and disease progression, with target IOP achieved and no progression requiring follow-up every 6 months (or 12 months if stable >6 months), and target IOP not achieved or progression present requiring follow-up every 1-2 months 3
Surgical interventions, including trabeculectomy, glaucoma drainage devices, and minimally invasive glaucoma surgery (MIGS), may be necessary for refractory cases to create a new drainage pathway and divert aqueous humor, as suggested by the American Academy of Ophthalmology 3
Laser therapy, including selective laser trabeculoplasty (SLT) and argon laser trabeculoplasty (ALT), may be used if medical therapy is insufficient to improve trabecular meshwork outflow, according to the American Academy of Ophthalmology 3

Several medications can precipitate AACG, including adrenergic agents, anticholinergic medications, tricyclic and tetracyclic antidepressants, and sulfa-based drugs, which can cause AACG through different mechanisms, such as pupillary block or ciliary body edema 2
The American Academy of Ophthalmology recommends considering alternatives to SSRIs/NRIs for patients with diagnosed angle closure glaucoma, and monitoring intraocular pressure (IOP) regularly during treatment, as tricyclic antidepressants pose a higher risk due to stronger anticholinergic effects, while SSRIs and SNRIs pose a moderate risk 2
The American Academy of Ophthalmology suggests screening for glaucoma risk factors and history before prescribing SSRIs/NRIs, considering ophthalmologic consultation for high-risk patients, and informing patients about potential risk and symptoms to watch for during treatment 2