Evaluation of a uniplanar pupil expansion ring in small-pupil cataract surgery: a feasibility study

Purpose: The aim of this study was to evaluate the effectiveness of a disposable uniplanar pupil expansion device in small-pupil cataract surgery.

Methods: This is a feasibility study carried out at the Rothschild Foundation, Paris, France. Patients undergoing routine cataract surgery with a dilated pupil size < 6 mm, and who agreed to participate in the study were included. The trial enrolled 25 patients, of whom 21 proceeded to cataract surgery using the pupil expansion device to be evaluated. The pupil diameter was measured at defined stages during the cataract surgery, which was performed by a single surgeon, in a single center setting. The 1st generation Bhattacharjee pupil expansion ring was used if the preoperative pupil size was < 6 mm. Intraoperative and postoperative adverse events were recorded.

Results: Pupil size immediately after the Bhattacharjee ring implantation was ≥ 6 mm for 15 eyes (71.4%). The mean dilated pupil size before ring insertion was 4.5 ± 0.8 mm (range 2.5-5.8 mm), and the mean pupil size after ring insertion was 6.1 ± 0.3 mm (range 5.9-6.8 mm). Mean pupil size following removal of the ring was 4.2 ± 0.8 mm (range 2.5-5.4 mm). Two adverse events occurred during the surgeries: 1 Bhattacharjee ring broke prior to implantation, and 1 implanted Bhattacharjee ring was unstable and removed before the end of the surgery. No postoperative adverse event was recorded.

Conclusions: The Bhattacharjee ring is an effective pupil expansion device, which facilitates stable pupil expansion during cataract surgery. This study was registered as a clinical trial at clinicaltrials.gov under the number NCT02434588.