primary%20angle-closure%20glaucoma
PRIMARY ANGLE-CLOSURE GLAUCOMA
Primary angle-closure is the synechial or appositional closure of the anterior chamber angle secondary to multiple mechanisms resulting in raised intraocular pressure and structural changes in the eyes.
Iridotrabecular contact is the hallmark of primary angle-closure  and the most commonly identified sign which indicates that treatment is required.
It is defined by at least 180 degrees of iridotrabecular contact together with an elevated intraocular pressure or peripheral anterior synechiae or btoh
Primary angle-closure glaucoma is the presence of glaucomatous optic neuropathy.

Surgical Intervention

Laser Peripheral Iridotomy

  • Definitive treatment of acute and chronic angle-closure glaucoma with a pupillary block component
    • Preferred surgical treatment due to its favorable risk-benefit ratio
    • Relieves pupil block and can prevent the formation of peripheral anterior synechiae (PAS)
  • In angle-closure with plateau iris mechanism, peripheral laser iridotomy will help confirm the diagnosis and will eliminate pupillary block component, if present
  • Should only be done once corneal edema (if present) or acute angle-closure crisis (AACC) attack has been medically cleared
  • Also indicated in suspected cases of angle closure due to posterior mechanisms or plateau iris to eliminate any possible pupillary block component
  • Prophylactic iridotomy is also indicated in the fellow eye, if it is similarly predisposed (if the chamber angle is anatomically narrow), to prevent an attack
  • Effective as a preventive measure in patients at moderate to high risk of experiencing an acute attack
  • Argon laser iridotomy has a superior closure rate than Nd:YAG laser
  • Possible complications include visual disturbances (eg glare, spots, halo, lines, shadows), temporary blurring of vision, intra-op bleeding, transient elevation of intraocular pressure (IOP), inflammation, localized lens opacities, posterior synechiae
  • Rarely, may cause cystoid macular edema, retinal damage, malignant glaucoma, decompression retinopathy, retinal and subhyaloid hemorrhage, Descemet's membrane detachment
  • Post-operative management includes checking of IOP 30 minutes-2 hours after the surgery and repeat by 24-48 hours
    • Repeat gonioscopy to check for PAS and/or plateau iris configuration
    • Check the patency of the peripheral iridotomy

Peripheral Iridectomy

  • Has been largely replaced by iridotomy in recent years
  • Alternative to laser iridotomy when acute attack cannot be broken or when the cornea fails to clear sufficiently for laser iridotomy to be performed
  • Advantages are that it can be done even when cornea is cloudy, permits deepening of the anterior chamber breaking newly formed PAS
  • Risks are similar as with other invasive ocular surgeries

Laser Peripheral Iridoplasty

  • Contracts peripheral iris resulting to widening of the anterior chamber angle and re-opening of the appositionally closed segments 
  • Stretches the iris and deepens the chamber angle to reduce risk of progressive synechial closure
  • Can be used to eliminate appositional angle closure caused by nonpupillary block mechanisms
  • May be done prior to laser iridotomy when acute attack cannot be broken and cornea is cloudy or hazy
    • May be performed, in addition to iridotomy, in cases of iris plateau configuration and when the angle remains narrow despite a patent laser iridotomy (plateau iris syndrome)
  • Complications include iris atrophy and non-dilatable pupil (established), mild iritis, mydriasis, IOP spikes and corneal endothelial burns

Lens Extraction with Intraocular Lens Implant

  • Significantly widens anterior chamber angle in angle-closure glaucoma and in eyes with narrow, occludable angles based on various studies
  • Helpful in cases where either the lens thickness or anterior position is thought to be the main mechanism involved in the acute episode of angle-closure
    • Recent data suggest that cataract and clear lens extraction may be more effective at controlling IOP than traditional therapy

Anterior Chamber Paracentesis

  • May be done prior to laser iridotomy when acute attack cannot be broken and cornea is too cloudy or hazy
  • Provides rapid symptom relief and prevents further damage to the optic nerve and trabecular meshwork from the acutely elevated IOP

Goniosynechialysis

  • Restores drainage function through mechanical lysis of adhesions that lead to angle scarring
  • Scarring present for <1 year tends to have better results

Phacotrabeculectomy, Trabeculectomy, Phacoemulsification

  • Reduce IOP and need for antiglaucoma agents, increase anterior chamber depth
    • Phacoemulsification results in less post-op complications
  • Trabeculectomy may be needed in asymptomatic chronic angle closure with a pressure >35 mmHg, >6 clock hours of PAS, and/or established glaucomatous optic neuropathy
Editor's Recommendations
Most Read Articles
29 Nov 2019
Metformin Extended Release 500 mg,750 mg, and 1000 mg
4 days ago
Men who undergo flexible cystoscopy, particularly with a longer dwell time, may benefit from intraurethral lidocaine as it provides significant pain reduction, suggest the results of a meta-analysis. Evidence is lacking for other tested interventions.
Pearl Toh, 4 days ago
Getting just under one extra hour of sleep per night can go a long way for the health of college students, who are often sleep-deprived, a study suggests.
3 days ago
While douching is not associated with the risk of ovarian cancer, the combination of talc and commercially available douches contributes to a modest increase in the risk of epithelial ovarian cancer beyond that conferred by talc use alone, as shown in a recent study.