Retinal Sensitivity with Pupil Dilatation and Without Pupil Dilatation Measured on Central Static Threshold Perimetry.

Abstract

Objective: The aim of the study was to find retinal sensitivity values with and without pupil dilatation in normal individuals. Methods: Cohort study on 60 normal individuals was carried out. All individuals were subjected to perimetry to measure retinal sensitivity. Fixation loss, false positive, false negative, pattern defect, overall defect, fluctuations, hill of vision (HoV) slope and HoV slope 3Ⱐwere examined during the test. Normal pupil range were taken as 2 - 4mm and dilated pupil was declared if it is ≥6 mm. Tropicamide 10% drop was instilled in both eyes to dilate pupil. Perimetry was done before and after dilatation. Paired sample t-test applied to analyze data. P value less than 0.05 was taken as significant. Retinal sensitivity values were taken using Medmont central static threshold perimeter. This study was conducted in the month of October, November and December 2014. Results: Out of 60 normal subjects 33 were males and 27 females. Retinal sensitivities values observed in each eye (N=120) before and after pupil dilatation were compared. Shapiro-Wilk test applied and the data were parametric. By applying paired sample t-test, there was no significant difference between Pattern defect, Overall defects, and HoV slope with and without pupil dilatation (p˃0.42, p˃0.28 and p˃0.16 respectively). But there was marked differences between fluctuations with and without pupil dilatation (p<0.000001). Conclusion: There is no significant difference in retinal sensitivity before and after pupil dilatation. This study recommends that perimetry can be done with dilated pupils. Another study is required to validate this data in abnormal eyes particularly in glaucomatous eyes.