ANGLE CLOSURE GLAUCOMA

GENERAL  INFORMATION

It is a medical emergency. patient presents with ocular and systemic symptoms. Ocular symptoms include pain, redness and reduced visual acuity. Systemic symptoms include nausea and vomiting. On examination there is conjunctival injection, corneal edema, oval non reactive dilated pupil. The intra ocular pressure is high. Treatment involve 250ml intravenous mannitol 20% given over 30 minutes. Tab Acetazolamide 250mg 4 times a day with vitamin K  to prevent paresthesia. Pilocarpine eye drops 4 times a day. Timolol eye drops twice a day. analgesic like diclofenac sodium parenteral and antiemetic like metoclopramide parenteral is given. 

DEFINATION

Primary angle closure disease includes a spectrum of conditions in which the peripheral iris moves forwards to block the openings of the trabecular meshwork in an occludable angle, causing a rise of intraocular pressure

RISK FACTORS

1. A short eye: HYPERMETROPIC EYE

2. Smaller corneal diameter

3. A shallow anterior chamber, and

4. Relative anterior positioning of the lens–iris diaphragm

MECHANISM OF ANGLE CLOSURE

• Lens continue to grow all life thus occluding mid dilated pupil especially evening or  in near work when lens is in accommodated state. Iris move forward to block trabecular meshwork Which causes increase in intraocular pressure

• plateu iris configuration

• peripheral crowding of iris

CLINICAL FEATURES

Bilateral disease  but asymmetrical 

occludabe angle ( inability to see the posterior trabecular meshwork over more than 180/270 degrees, with the patient looking straight ahead on gonioscopy)

symptoms

1. nausea vomiting

2. eye pain

3. eye redness

4. reduced vision or halos in front of eye

signs

1. ciliary congestion

2. corneal edema

3. narrow anterior chamber

4. vertically mid dilated pupil

5. glaucomflecken

A dark room prone provocative test 

1. may be used as a diagnostic tool to precipitate closure of the angle in such eyes. 

2. Baseline intraocular pressure and gonioscopic findings are recorded 

3. patient asked to stay in a dark room, in prone position for 1 hour, without sleeping. 

4. the intraocular pressure and gonioscopy are noted with minimal illumination.

5. A rise in intraocular pressure of 8 mmHg or more in the presence of a closed angle identifies eyes predisposed to PACG.

cyloplegic/mydriatic tests are less physiological

Treatment

control IOP by

1. systemic:

intravenous mannitol 20% 300 ml over 30 minutes  after confirming that patient has no cardiovascular problem. It can be repeated after 6 hours

or oral glycerin 50 ml taken with lime juice after excluding diabetes

2. topical:

pilocarpine 2% four times a day

timolol eye drops twice a day

tab acetazolamide 250 mg four times a day

3. pressure on central cornea with cotton tipped applicator

will push the iris away from lens 

peripheral laser iridotomy

after control of IOP all glaucomatous eyes and contralateral eyes should have peripheral laser iridotomy done to prevent further attack of acute congestive glaucoma. 

pupil is meiosed with pilocarpine

a crypt is identified

YAG laser  with a power of 3-6 milli  joules is applied 

opening of 200 micron is made

a gush of aqueous shows successful iridotomy

on first postoperative day patency of iridotomy is examined and gonioscopy is reevaluted