Comparison Of Three Different Imaging Modalities In Predicting Intra-Operative Posterior Polar Capsular Rupture During Posterior Polar Cataract Surgery Using Femtosecond Laser

This comparitive study was conducted at a Tertiary Eye Care Centre, New Delhi, India, where the efficacy of three imaging modalities to determine intra-operative posterior capsular rupture in posterior polar cataracts.

66 eyes of patients with posterior polar cataract undergoing FLACS were included in this prospective, comparative, Interventional Study. Dense, hard cataracts, obscuring the view of the posterior capsule (PC) were excluded. During slit lamp examination, the anterior vitreous phase was examined for signs of lenticular material or any pre-existing PC defect. All patients underwent the PC integrity test with AS-OCT & Pentacam HR pre-operatively, and the Femto based ASOCT intra-operatively. The results of all the three investigations were recorded as 'Intact' or 'Dehiscent' Capsule. All patients underwent FLACS. Intraoperative integrity of the PC was noted and classified as dehiscent or intact.

The mean size of the Posterior polar opacity observed was 3.01 mm ± 0.87 mm, ranging from 2 mm to 5 mm. 13 patients had size of PPC opacity more than 4 mm, among whom 4 patients (30.77%) had intraoperative PC dehiscence. The Femto-based ASOCT and the ASOCT were equally effective in predicting the PCR preoperatively with an accuracy of 83.33% while Scheimpflug imaging could only predict 16.67%. The Specificity and Positive Predictive Value of all the three investigations in predicting PCR preoperatively was 100%. The Negative Predictive Value of ASOCT and Femto based ASOCT was observed to be same i.e. 98.36%, higher than that of Scheimpflug imaging which was 92.31%

We thus conclude that the AS-OCT and Femto-based AS-OCT are highly sensitive and efficacious in assessing the status of posterior capsule in the patients of posterior polar cataract prior to surgery. The Scheimpflug imaging is less sensitive in assessing the status of posterior capsule of lens. The rate of PCR in patients of PPC has a positive association with the size of PPC.