Preoperative assessment of posterior capsular integrity using a posterior segment OCT with a +20 D lens: The 'conical sign' to suggest capsular deficiency in posterior polar cataracts.

Purpose: To study the morphology of posterior polar cataracts and posterior lens capsules using modified posterior segment optical coherence tomography (m-OCT).

Setting: Dr. Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India.

Design: A prospective observational case series.

Methods: Patients with clinically diagnosed posterior polar cataracts were included. The routine posterior segment OCT was modified by placing an aspheric +20.00 diopter lens along its aperture, enabling it to visualize the anterior segment structures. Cases of posterior polar cataract were assessed preoperatively using this method to study the morphology of posterior lens cortex and the posterior capsule. All m-OCT observations were performed by 2 observers, and findings were recorded.

Results: A total of 26 eyes of 17 patients were included. The mean age of patients was 53 years. The morphology of the cataract appeared as hyperreflective opacity just anterior to the posterior capsule, subsequently involving it, and with variable hyporeflective spaces. An intact posterior capsule showed a regularly convex contour, whereas a loss in the tracing of posterior capsule at the paracentral region and disturbance in contour with a localized protrusion of lens matter (the conical sign) depicted a possible posterior capsule dehiscence. Four (15.38%) of 26 eyes showed the conical sign, and this posterior capsule defect was confirmed intraoperatively in all cases.

Conclusions: In posterior polar cataracts, the conical sign could be a valuable clue to predict preexisting posterior capsule dehiscence and could be identified on a m-OCT.