Anterior Segment Spectral Domain Optical Coherence Tomography and Histopathologic Study of Peters Anomaly

Abstract

Purpose : To report the results of anterior segment examination using Spectral Domain Optical Coherence Tomography (SD-OCT) and histopathologic study of excised corneal tissue in eyes of patients with Peters anomaly. The study aims at studying the natural history of corneal edema associated with Peters anomaly and determining endothelial layer presence histologically and corneal thickness by SD-OCT. Results of this study may guide the indications and nature of surgical intervention in these patients, including anterior lamellar keratoplasty.

Methods : Anterior segment SD-OCT examination was performed on 18 eyes of 12 children with Peters anomaly using SD-OCT. Subjective morphologic analysis of anterior segment structures and corneal thickness measurement using the pachymetric map display were done (Figure 1A). Corneal thickness measured as the maximum thickness in a 6 mm zone was correlated to patient’s age. Histopathlogic study using Periodic Acid-Schiff (PAS) stain of three excised corneal buttons from eyes of children diagnosed with Peters anomaly undergoing penetrating keratoplasty (PK) was performed.

Results : Corneal thickness inversely correlated with age (linear correlation coefficient R=0.6) with lower corneal thickness values in older children (P=0.01) (Figure 1B). Histopathologic examination revealed presence of corneal endothelium in areas of absent or attenuated Descemet’s membrane in two out of three eyes (Figure 2A and 2B; arrows point at areas of termination of Descemet’s membrane; arrow heads point at endothelium present in areas with absent or attenuated Descemet’s). The third corneal tissue (Figure 2C) revealed the presence of a retrocorneal membrane, with underlining attenuated and variably present endothelium (arrows).

Conclusions : The lower corneal thickness values observed in older children with Peters anomaly can possibly be attributed to better endothelial cell function and expansion of endothelial cells in areas of absent or attenuated Descemet’s membrane. These results may help optimize indications for keratoplasty and may propose deep anterior lamellar keratoplasty as a potentially viable therapeutic option, preserving the patient's own endothelium and thus substantially reducing the risk of graft rejection.

This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.