ICRS depth less than expected using OCT

Depth of intrastromal corneal ring segments (ICRS) is less than expected in myopic patients when measured by OCT, claims a recent paper.

Dr M. Naftali et al., Ophthalmology Unit of the Baruch Padeh Medical Centre, Poriya, Israel, included ten eyes of eight patients with 18 ICRS in a retrospective, comparative study.

Eleven ICRSs were Intacs and seven were Kerarings. AS-OCT was used to measure the shortest distance from the epithelium to the segment at three points. These points were proximal, middle and distal to the incision.

Mean depth of the 18 segments was 360±68 µm and the mean maximal and minimal depths were 383±70 and 336±72 µm, respectively. Mean depths of the proximal, middle and distal points were 358±79, 361±77 and 362±59 µm, respectively.

There were no segments that appeared more superficial than others and there were no differences between Intacs and Kerarings depths. However, there was a significant difference between the expected ICRS depth and OCT measurement, with ICRS depth being less than expected.

The abstract can be viewed in the European Journal of Ophthalmology.