Preoperative OCT lens evaluation in posterior subcapsular cataract - prevention of complications from phacoemulsification.

PURPOSE

To assess the possibility of anterior segment optical coherence tomography (AS-OCT)-based preoperative evaluation of the lens in order to prevent and predict intraoperative complications of posterior subcapsular cataract (PSC) surgery.

METHODS

This prospective study included 512 eyes diagnosed with PSC. AS-OCT was performed using Line, Cross Line and 3D Cornea scans to visualize the posterior capsule. The posterior capsule and opacities in the subcortical and cortical lens, their relationship and the state of the retrolenticular space were assessed. The study sample was divided into three groups while taking into account the revealed morphological changes in the lens. Groups 1, 2, and 3 comprised 312, 185 and 15 eyes, respectively, with each group characterized by a specific type (1, 2 or 3) of morphological AS-OCT changes in the PSC. Surgery consisted of ultrasound phacoemulsification with intraocular lens implantation. Well-known measures related to cataract surgery stages were performed, if required, to preserve the integrity of the posterior capsule, while taking into account the type of PSC changes. We preoperatively determined the eyes at risk for intraoperative posterior capsular rupture (PCR) and detection of posterior capsular plaque (PCP), and compared this data with the postoperative data on the state of the posterior capsule.

RESULTS

The PSC cases with an expected rate of intraoperative complications of 0 to 10% were classified as those with a low risk, whereas the rest, with a high risk of complications. Only eyes with type 2 or type 3 PSC changes were expected to have a high risk of intraoperative PCP, and only eyes with type 3 PSC changes, a high risk of PCR. In groups 1, 2 and 3, the rates of intraoperative PCP were 0%, 100% and 46.7%, respectively, and the rates of intraoperative PCR, 0%, 0% and 53.3%, respectively. There was a significant positive correlation between preoperative OCT-based morphology of the lens and intraoperative complications (r = 0.88, p ≤0.001). Sensitivity and specificity for the method of AS-OCT-based evaluation of risks of intraoperative complications in PSC surgery were 98.8% and 96.5%, respectively.

CONCLUSION

AS-OCT allows evaluating preoperatively posterior lens opacification morphology and posterior capsular changes, determining the risks of complications, and performing surgical planning for PSC.

KEY MESSAGES

What is Known? Complications (posterior capsule (PC) rupture with or without vitreous loss and residual PC plaque) are common in, and affect the expected outcome of, posterior subcapsular cataract (PSC) surgery. What is new? PC plaque is most likely in eyes with preoperative type 2 changes in the PSC, whereas eyes with preoperative type 3 changes are likely to show PC rupture or residual PC plaque. AS-OCT enables an experienced surgeon to predict the risks of intraoperative complications in, and perform surgical planning for, PSC surgery.