Corneal Melt of Incisions Overlying Corneal Ring Segments: Case Series and Literature Review

Abstract

Purpose: 

To describe 4 cases of corneal melt encountered after insertion of intrastromal corneal ring segments (ICRS) for ectasia, propose a theory as to the etiology of the melt, and review relevant literature.

Methods: 

Retrospective observational case series. Eyes with corneal melt after ICRS implantation were identified and the charts were reviewed. Relevant literature was reviewed to establish the overall incidence of corneal melt after ICRS and potential contributing factors.

Results: 

Each of our 4 cases of corneal melt occurred in an eye with a corneal incision overlying the ICRS. Case 1 occurred in an eye with pellucid marginal degeneration in which the ICRS incision overlaid the segment. Case 2 occurred in an eye after radial keratotomy that underwent ICRS to address refractive instability. Corneal melt developed around a gaping radial keratotomy (RK) incision. Case 3 occurred in an eye after radial keratotomy and subsequent hyperopic laser in situ keratomileusis that developed ectasia for which an ICRS was inserted. Corneal melt developed in association with an RK incision overlying the ICRS in the area of a peripheral corneal ulcer. Case 4 occurred in an eye after radial keratotomy with an unstable cornea that underwent ICRS implantation for improved stability. The ring segment extruded through an overlying RK incision and corneal melt developed. The literature on ICRS implantation for keratoconus and ectasia was reviewed. Of 1835 eyes after ICRS implantation for keratoconus or ectasia, there were 12 reported cases of corneal melt (0.7%), a majority (7% or 58%) were associated with overlying incision.

Conclusions: 

Corneal melt is a rare complication of ICRS. We conclude that wound gape over ICRS contributes to the development of melt. Strategies can be employed to reduce the incidence of this rare but important complications of ICRS.