Abstract
Purpose :
To determine whether laser peripheral iridotomy (LPI) location affects post-operative dysphotopsia symptoms
Methods :
Design: Multicenter randomized, prospective, single masked trial
Participants: 539 South Indian subjects aged ≥ 30 years with primary angle closure suspect (PACS) or primary angle closure/ primary angle closure glaucoma (PAC/PACG)
Methods: Subjects were randomized to either bilateral superior or bilateral nasal/temporal LPI. Occurrence of new visual disturbances was evaluated before and 2 weeks after LPI using a questionnaire based on the 7-item Spaeth dysphotopsia symptoms. Multivariable logistic regression models were used to determine predictors of one or more new post-operative dysphotopsia symptoms.
Results :
Subjects randomized to superior LPI (N=273) and nasal/temporal LPIs (N=266) were matched with respect to ocular and demographic features (p>0.5 for age, gender and PAC/PACG diagnosis). Similar initial laser energy settings were used in both groups (p=0.5), though superior LPIs required greater number of shots (p=0.002) and greater total energy (p<0.001) than nasal/temporal LPIs. There were no significant differences in post-operative anterior chamber (AC) reaction or LPI area between the two groups (p>0.5 for all). Overall, 8.7% of all subjects reported presence of one or more new dysphotopsia symptoms post-LPI, with the most common new symptoms consisting of linear dysphotopsias, glare, and blurring in 2.8%, 4.1% and 4.2% of patients, respectively. Patients receiving superior LPI were not more likely to describe the new onset of one or more dysphotophopsia symptoms as compared to subjects undergoing nasal/temporal LPI (8.4% vs. 9.0%, p=0.8), nor did the frequency of any individual symptoms differ by group (p>0.2 for all). Multivariable logistic regression analysis demonstrated that PACG diagnosis (OR=2.66, 95% CI 1.20-5.88) predicted higher odds of new post-operative dysphotopsias while LPI location, LPI area, and total laser energy did not (p>0.1 for all).
Conclusions :
LPI location was not associated with statistically significant differences in post-operative dysphotopsia symptoms. PACG diagnosis, but not LPI location, LPI area or total energy, was associated with occurrence of new visual disturbances post-LPI.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.