Gonioscopic angle evaluation and its correlation with graft survival and post-operative ocular hypertension in patients of Descemet's stripping endothelial keratoplasty

Purpose: To evaluate the gonioscopic changes in patients receiving Descemet's stripping endothelial keratoplasty (DSEK) without pre-existing ocular hypertension (OHT) and to report its correlation with post-surgery OHT, graft survival, and visual outcomes. Methods: Adult patients who underwent DSEK surgery from April 2014 to March 2018 with at least 2 years of follow-up were analyzed in this retrospective study. Demographic details, indication of DSEK, necessary anterior and posterior segment findings, and the post-DSEK OHT details were documented. Results: A total of 58 patients (23 males and 35 females) with a mean age of 61.44 ± 8.8 years were included in the study. The most common etiology for DSEK surgery was pseudophakic bullous keratopathy in 47 eyes (81.03%). A total of 22.41% (13/58) eyes showed elevated intra-ocular pressure (IOP) following DSEK surgery. The most common cause of IOP elevation was steroid-induced OHT in seven eyes (12.06%). Gonioscopy examination revealed areas of peripheral anterior synechiae (PAS) in 17 (29.3%) eyes. OHT was found in 4/17 (23.5%) eyes having PAS. Three of these cases required trabeculectomy + goniosynechiolysis (GSL), and the fourth case required GSL alone to control IOP. These four cases also required repeat DSEK for failed grafts. The mean pre-operative best corrected visual acuity was 1.62 logMAR (range 1.17-1.77), which gradually improved to 0.79 logMAR (range 0.3-1.77) after 2 years (p < 0.00001). Conclusion: PAS was found to be an important factor associated with post-DSEK ocular hypertension in our study. OHT in PAS cases required definitive surgical treatments to control IOP. It adversely affected the graft survival and in turn affected visual outcomes also.