BACKGROUND: Evaluation of anterior segment parameters is crucial in ophthalmic procedures such as intraocular surgeries and contact lens fitting. However, the use of tropicamide in diabetic patients presents challenges due to its potential impact on biometric measurements. This study aims to investigate and compare the effects of 0.5% and 1% tropicamide on anterior segment parameters in diabetic patients.
METHODS: This double-masked randomized clinical trial enrolled 98 patients with diabetes mellitus. Participants were randomly assigned to receive either 0.5% or 1% tropicamide. Anterior segment parameters were measured using Pentacam HR (Oculus Optikgeräte GmbH, Wetzlar, Germany) before and 30 minutes after tropicamide administration. Parameters included anterior chamber depth (ACD), anterior chamber volume (ACV), anterior chamber angle (ACA), keratometry, central corneal thickness (CCT), white-to-white distance (WTW), and pupillary diameter (PD).
RESULTS: Both concentrations of 0.5% and 1% tropicamide induced significant changes in anterior segment parameters. There was a notable increase in PD (2.99 ± 0.62, 3.11 ± 0.55, respectively, both P-values < 0.001), ACD (both 0.10 ± 0.05, both P-values < 0.001), ACV (16.69 ± 9.56, 17.51 ± 9.26, respectively, both P-values < 0.001), and WTW (0.06 ± 0.14, 0.03 ± 0.30, respectively, both P-values < 0.001), along with a decrease in ACA (-3.50 ± 10.65, -3.30 ± 6.87, P-value < 0.001 and P-value=0.001, respectively), and CCT (-6.10 ± 8.06, -6.39 ± 9.97, respectively, both P-values < 0.001) post-dilation. However, no significant changes were observed in keratometry (front Km (-0.03 ± 0.19, -0.04 ± 0.21, respectively), back Km (0.01 ± 0.05, 0.004 ± 0.05, respectively), P-values> 0.05).
CONCLUSIONS: Both concentrations of tropicamide exhibited comparable effects on anterior segment parameters in diabetic patients. These post-dilation changes should be considered for accurate intraocular lens power calculation and decision-making for cataract, phakic intraocular lens, and refractive surgeries.

: To determine the diagnostic accuracy of manual regurgitation on pressure over the lacrimal sac (ROPLAS) versus lacrimal irrigation for screening nasolacrimal duct obstruction (NLDO) in adults prior to intraocular surgeries.
This cross-sectional study took place in a tertiary eye care hospital in South Tamil Nadu, India. From January to December 2017 and included consecutive patients who presented for routine cataract surgery. Prospective data collection occurred in 8369 eyes of patients who underwent cataract surgery. All patients underwent ROPLAS testing by an ophthalmologist followed by lacrimal irrigation by trained ophthalmic assistants, rechecked or confirmed in equivocal cases by ophthalmologists who were masked to the ROPLAS status. The primary outcome, the sensitivity, specificity, positive, and negative predictive values to detect lacrimal occlusion by ROPLAS compared with lacrimal irrigation with 95% confidence intervals was estimated.
: A total of 8369 eyes underwent cataract surgery during the time periods of the study. ROPLAS and lacrimal irrigation were performed in all eyes. The sensitivity of ROPLAS to diagnose NLDO correctly was 54.5% (95% CI, 44.8%-63.9%) and its specificity was 100% (95% CI, 100%-100%). The positive and negative predictive values were 75.3% (95% CI, 65.6%-83.0%) and 99.4% (95% CI, 99.2%-99.5%), respectively.
: We found that ROPLAS when used alone had very low sensitivity and low positive predictive value in detecting NLDO prior to cataract surgery as compared with lacrimal irrigation. Hence, we recommend performing ROPLAS and lacrimal irrigation in every patient as part of the routine preoperative workup prior to cataract surgery.