Superior Laser Peripheral Iridotomy Confers Greater Risk of Negative Dysphotopsias than Temporal Laser Peripheral Iridotomy.

PURPOSE: Laser peripheral iridotomy (LPI) is largely used as the first course of action to treat primary angle-closure (PAC). Previous literature has long been divided on the relationship between iridotomy position and dysphotopsia onset. The current study investigates whether there is a correlation between iridotomy position, temporal versus superior, and new onset post-operative dysphotopsia rates. METHODS: The project involves a retrospective chart review of 2,385 lasered eyes. Demographic data and iridotomy-specific data including laterality, iridotomy position, and new onset post- operative dysphotopsias were recorded. RESULTS: Of 2385 eyes with LPIs, 217 (9.10%) experienced postoperative dysphotopsia. Superior and temporal LPIs were associated with total dysphotopsia rates of 11.20% and 8.01%, respectively. The percentage distribution of dysphotopsias among negative, positive, and non-specific categories were 2.81%, 4.99%, and 1.26%, respectively. Superior LPIs are associated with a greater risk of new onset dysphotopsia than temporal LPI (p = 0.0107), specifically negative dysphotopsia (p < 0.0001). CONCLUSIONS: Patients with superior LPI were more likely to experience negative dysphotopsia onset than those with temporal LPI. Among negative dysphotopsias, positive dysphotopsias, and non-specific symptoms, only negative dysphotopsias were significantly impacted by iridotomy position. Results may influence providers to perform LPI temporally to prevent negative dysphotopsia. Further research into the etiology of dysphotopsia may elucidate further clinical decisions to protect patients from dysphotopsia onset.

Effect of glaucoma on identification of bottle cap color in ophthalmic medications.

A prospective, nonrandomized, observational trial of 60 glaucoma patients to correlate visual acuity and visual field with ability to distinguish bottle cap color of commonly used ophthalmic medications was conducted. A total of 103 eyes from 60 patients (30 women) were evaluated. The mean logMAR acuity was 0.34±0.54 (approximately 20/45 Snellen acuity), average Humphrey Visual Field (HVF) mean deviation was -8.58±8.69 dB, mean Ishihara plates (out of 14) were 11.78±4.15, and bottle cap color score (out of 10) was 8.56±2.51. Multiple linear regression analysis revealed an independent correlation of visual acuity (P=0.0137) and Ishihara score (P<0.001) with cap color score, but no significant effect with visual field mean deviation (P>0.05). Glaucoma patients with poor visual acuity, but not necessarily advanced visual field loss, are likely to have difficultly identifying the color of their bottle caps. Physicians should be cognizant of this potential issue when reviewing medications with patients.

Squeeze Me if You Can: Variability in Force Requirements to Extract a Drop From Common Glaucoma Bottles.

PURPOSE: To determine the force requirements to dispense a single drop from commonly prescribed brand and generic topical glaucoma medications and correlate these findings with pinch strength in a representative patient population. PATIENTS AND METHODS: Four bottles of each medication were tested: 2 in the vertical and 2 in the horizontal orientation. Bottles were housed in a customized force gauge apparatus designed to mimic ballpoint fingertip contact with a bottle tip. For all bottles, each of the first 10 dispensed drops was tested and then tests were performed in increments of 10 until the bottle was empty. For each tested drop, the maximum force and displacement were electronically measured. Concurrently, maximum pinch strength was measured on consecutive glaucoma patients. RESULTS: A total of 84 bottles from 21 bottle designs were tested. There was significant variability across the designs, with roughly a 7-fold (0.67 to 4.49 kgf) and 4-fold (0.81 to 3.00 kgf) difference in force requirements in the vertical and horizontal positions, respectively. Of 53 enrolled patients in the glaucoma clinic, the mean pinch strength was 5.05 (range, 1.23 to 10.4 kgf) and 4.82 (range, 1.47 to 10.67 kgf) kgf for the right and left hands, respectively. CONCLUSIONS: There is statistically significant variability in the force required to squeeze a drop from common glaucoma medications, and a representative sampling of clinic patients suggests that many likely struggle with the force requirements of several bottle designs. These data further support standardization of topical glaucoma drug delivery and design.