MAR 04, 2008
Previously there have been no randomized studies comparing laser peripheral iridotomy (LPI) with cataract surgery in patients with acute angle closure glaucoma (AACG) after breaking the acute attack with medication only. This prospective, randomized study provides new evidence suggesting that cataract surgery is superior to LPI in preventing future intraocular pressure rise (IOP) in patients with AACG.
The study included 62 subjects (62 eyes) who were at least 50 years old, had been diagnosed with acute primary angle closure (APAC) that was aborted with medication, and had a cataract with best-corrected visual acuity worse than 20/30 in the cataractous eye. They were each randomized to receive either early phacoemulsification with posterior chamber intraocular lens implantation or LPI within days after abortion of the APAC attack once IOP dropped below 21 mmHg and inflammation levels had sufficiently settled.
There was a significant difference between the prevalence of postintervention IOP rise (3.3% of the phacoemulsification patients vs. 46.7% in the LPI patients after 18 months), and the mean number of medications required to maintain IOP at 21 mmHg or lower after 18 months was significantly higher in the LPI group (0.90±1.14 vs. 0.03±0.18). Early phacoemulsification should be considered a definitive treatment to prevent IOP rise in patients with cataract. A presenting IOP above 55 mmHg, and early phacoemulsification appeared to be more effective than LPI at preventing IOP rise after breaking an acute attack, the researchers concluded.
Because this is a prospective randomized study with a long follow-up period and statistically significant results, the recommendations of the study seem to be valid. Once inflammation has settled, a successful phacoemulsification by an experienced surgeon should offer long-term IOP control in patients with cataract and AACG after the IOP has been normalized with medications.
It should be noted, however, that the study did not evaluate patients with chronic AACG, without cataracts, or in whom the acute attack of AACG could not be halted.