Randomized Trial of Early Phacoemulsification versus Peripheral Iridotomy to Prevent Intraocular Pressure Rise after Acute Primary Angle Closure
Presented in part at: 1st World Glaucoma Congress, July 2005, Vienna, Austria.
Received 23 March 2007; received in revised form 22 October 2007; accepted 22 October 2007. published online 03 January 2008.
Purpose
To compare the efficacy of early phacoemulsification versus laser peripheral iridotomy (LPI) in the prevention of intraocular pressure (IOP) rise in patients after acute primary angle closure (APAC).
Design
Prospective randomized controlled trial.
Participants
Sixty-two eyes of 62 Chinese subjects, with 31 eyes in each arm.
Methods
Subjects were randomized to receive either early phacoemulsification or LPI after aborting APAC by medications. Patients were followed up on day 1; week 1; and months 1, 3, 6, 12, and 18. Predictors for IOP rise were studied.
Main Outcome Measures
Prevalence of IOP rise above 21 mmHg (primary) and number of glaucoma medications, IOP, and Shaffer gonioscopy grading (secondary).
Results
Prevalences of IOP rise for the LPI group were 16.1%, 32.3%, 41.9%, and 46.7% for the follow-ups at 3, 6, 12, and 18 months, respectively. There was only one eye (3.2%) in the phacoemulsification group that had IOP rise at all follow-up time points (P<0.0001). Treatment by LPI was associated with significantly increased hazard of IOP rise (hazard ratio [HR], 14.9; 95% confidence interval [CI], 1.9–114.2; P = 0.009). In addition, a maximum IOP at presentation > 55 mmHg was associated with IOP rise (HR, 4.1; 95% CI, 1.3–13.0; P = 0.017). At 18 months, the mean number of medications required to maintain IOP ≤ 21 mmHg was significantly higher in the LPI group (0.90±1.14) than in the phacoemulsification group (0.03±0.18, P<0.0001). Mean IOP for phacoemulsification group (12.6±1.9 mmHg) was consistently lower than that of the LPI group (15.0±3.4 mmHg, P = 0.009). Mean Shaffer grading for the phacoemulsification group (2.10±0.76) was consistently greater than that of the LPI group (0.73±0.64, P<0.0001).
Conclusion
Early phacoemulsification appeared to be more effective in preventing IOP rise than LPI in patients after abortion of APAC. High presenting IOP of >55 mmHg is an added risk factor for subsequent IOP rise. For patients with coexisting cataract and presenting IOP of >55 mmHg, early phacoemulsification can be considered as a definitive treatment to prevent IOP rise.
Available online: December 27, 2007.
1Department of Ophthalmology & Visual Sciences, Chinese University of Hong Kong, Hong Kong Eye Hospital, Hong Kong, China.
2Department of Ophthalmology & Visual Sciences, Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong, China.
Correspondence and reprint requests to Prof Dennis S. C. Lam, Chairman, Department of Ophthalmology & Visual Sciences, Chinese University of Hong Kong, 3/F, Hong Kong Eye Hospital, 147K Argyle Street, Kowloon, Hong Kong, China.
Manuscript no. 2007-392.
No author has any financial/proprietary interest in the article's subject matter.
Fully supported by the Research Grants Council, Hong Kong, China (Competitive Earmarked Grant; project no. CUHK4350/03M/2004).
ABSTRACT