Purchase this article with an account.
Rick Trevino, William Eric Sponsel, Carolyn Majcher, Carissa Villaflor, Jobeth Nozicka; Effect of laser peripheral iridotomy location on post-operative visual function. Invest. Ophthalmol. Vis. Sci. 2019;60(9):2824.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
The purpose of this study is to evaluate the influence of superior and temporal laser peripheral iridotomy (LPI) location on post-operative best corrected visual acuity (BCVA) and contrast sensitivity (CS).
Primary angle-closure patients or suspects were randomized to receive LPI temporally in one eye and superiorly in the other. All LPIs were performed by one surgeon (WES). LPIs were placed between 11:00-1:00 and directly at 9:00 or 3:00 with deliberate effort to avoid the high risk tear prism area. Patients were masked to LPI location in each eye. BCVA and CS with and without glare and a dysphotopsia questionnaire were evaluated preoperatively and 1 month post-operatively.
21 patients (17F, 4M; Mean age: 53y) were recruited. 76% (16) self-identified as Hispanic, 19% (4) white and 5% (1) Black. All but 2 had brown iris color. In 13 cases the LPI was placed temporally OD and in 8 it was temporal OS. There was no significant difference in laser parameters between superior and temporal LPIs. There was no significant change in BCVA following either superior (mean±SD: 54.5±4.1 to 54.4±5.9 letters; p=.06, t-test) or temporal (51.5±6.4 to 53.7±5.3 letters; p=.93) LPI. BCVA recorded under glare condition also did not change significantly. CS evaluated with the Pelli-Robson chart and the CSV-1000 test (with and without glare) were unchanged following either superior or temporal LPI. There was a general trend of fewer dysphotopsias being reported post-operatively, but this decline only achieved statistical significance in with blur following temporal LPI (pre-op: 12 patients; post-op: 2 patients; p=.04; Wilcoxon signed rank).
Our results indicate that there is no significant detrimental effect on visual function of either superior or temporally positioned LPIs in this predominantly Hispanic cohort. These findings may not generalize to individuals of Northern European ancestry due to differences in iris thickness. Greater iris thickness may act as a louver to limit stray light entering the eye.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.
Mean (SD) change in BCVA following LPI. There was no significant change from baseline (all p>0.05, paired 2-way t-test). OD/OS differences were not significant at either location.
Mean (SD) change from baseline in CSV-1000 score following LPI. Changes are not significant (p>0.05, Wilcoxon signed-rank)
This PDF is available to Subscribers Only