Causes and management of small pupil in patients with cataract

The purpose of the study was to present the causes and management of small pupil (<6 mm) in Greek patients with cataract.

About 1144 consecutive patients with cataract comprised the study group. The pupil size was measured after maximal dilation by means of Rosenbaum cards and Colvard pupillometer. Dilation regimen included phenylephrine 10%, tropicamide 1%, cyclopentolate 1%, and ketorolac trometamol 0.5% administered 3 times at 5 min intervals starting 1 h before surgery. The presence of possible risk factors for small pupil was recorded. The need of additional maneuvers and devices to dilate the pupil during cataract surgery was examined, and the complication rate in cases with small pupils was recorded.

Small pupil was observed in 78 out of 1144 eyes (6.8%, 95% confidence interval = 5.2%-8.8%). Nine eyes had pupil size <4 mm (0.78%) preoperatively. Six cases (0.52%) developed intraoperative pupillary miosis. The major cause of small pupil was pseudoexfoliation (PEX) in 47.4% (37/78) of patients. No significant associations were observed regarding age, gender, history of diabetes mellitus, the maturity of cataract, and phacodonesis. Techniques for small pupil management included pupil stretching in 14 cases (17.9%), use of iris hooks in 6 cases (7.7%), iris sphincter cuts in 2 cases (2.6%), and placement of a Malyugin Ring in 4 cases (5.1%). Seven eyes (9%) with small pupil had capsular rupture versus 16 eyes (1.5%) with normal dilation (P < 0.001).

Small pupil is not very common in Greek population, is mostly caused by PEX, and it is associated with increased complication rate.