Abstract
Purpose :
Appropriate mydriasis is an integral part of a successful cataract extraction (CE). Pupil size is probably most important variable in cataract surgery, as well as ophthalmological and optometric clinical practices. Maintenance of mydriasis contributes to procedural safety and efficiency. Methods to make mydriasis quicker and more long-lasting, but still safe were assessed. The current method is to use repeated separate drops of 2.5% phenylephrine (P) and 0.5% tropicamide (T). The addition of topical nonsteroidal anti-inflammatory drops, as a new therapy method, such as 0.5% ketorolac (K) have shown effectiveness in controlling post-operative pain, inflammation and maintenance of mydriasis during cataract surgery. We conducted a quantitative study to maximize pupil size using a gel solution that contained differing concentrations of P.
Methods :
After verifying eligibility and collecting baseline blood (BP) and intraocular pressure (IOPP) and pupil size data using a Neuroptics pupillometer, one eye of 214 subjects in 3 clinical centers in the USA, between 30 and 50 years was dilated with a topical ocular gel containing either 2.5% (n=50, 2.5%PTK)P, 0.5% T, and 0.5% K or 10% (n=188, 10%PTK) P, 0.5% T, and 0.5% K. Pupil size was measured every 15 mins for 2 hours after drug instillation.
Results :
Following the application of one drop, an increase in pupil size was noted starting at the 15 min measurement and latest the entire 2 hours in all subjects. The time to maximal dilation was on average an hour and 15 mins in all groups (p=0.8) but no difference in the pupil size was noted after the 30 min measurement. The largest pupil size was statistically different (p<0.001 overall) between the 2 groups, 7.9 ± 0.1 mm and 8.7 ± 0.05 mm, 2.5%PTK, and 10%PTK, respectively. However, the average maximal dilation was 3.8 ± 0.2 mm and 3.2 ± 0.08 mm in 2.5%PTK and 10%PTK, respectively (p<0.001 overall). No change in BP or IOP was noted. A partial analysis of iris color indicated that those with the darkest irises had the smallest average dilation.
Conclusions :
: Both drug combinations were safe and effective at causing a large, stable pupil dilation. These changes in thickness and concentrations show promise for use during cataract surgery and other eye procedures. However, more analysis of age, race, and iris color is needed to determine whether a higher dose of P is needed to achieve the desired results.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.