Comparison of pupil dilation in manual small incision cataract surgery using topical versus intracameral mydriatic agents – A randomised controlled trial

Abstract

The purpose of this research is to assess and compare the efficacy of an intracameral mydriatic solution with conventional topical agents in the completion of manual small incision cataract surgery (MSICS) in a black population. This randomised controlled trial was conducted among 102 patients undergoing MSICS under sub-tenon’s block. Mydriasis in the topical group was achieved with a pre-operative topical dilating combination of tropicamide 0.8% and phenylephrine 5% while surgery was commenced in patients in the intracameral group without dilation, and mydriasis was achieved intraoperatively with an intracameral solution of lidocaine 0.5% and adrenaline 0.001%. Pupil sizes were measured serially, before, and at four different junctures during surgery. The proportion of patients needing supplementary mydriasis in either group was noted, as well as post-operative pinhole visual acuity (VA). Data analysis was carried out using the Statistical Package for the Social Sciences Statistical Product and Service Solutions(SPSS) version 25.0 (IBM, Chicago, Illinois). The level of statistical significance was set at P < 0.05 at a 95% confidence interval. Mean pupil diameter before dilating and blocking was 2.5 ± 0.6 mm in the topical group and 2.5 ± 0.7 mm in the intracameral group (P = 0.752). This increased to 7.7 ± 1.1 mm and 7.4 ± 0.8 mm, respectively (P = 0.134), after administering either mydriatic agents. After that, mean pupil diameter progressively reduced in both groups but was significantly higher in the intracameral group at each point of measurement (P < 0.05). Postoperatively, there was no significant difference in the VA between the two groups (P < 0.05). Using an intracameral mixture of lidocaine and adrenaline gives adequate mydriasis for the successful completion of MSICS without pre-operative dilation.