Posters

High definition optical coherence tomography in the management of intrastromal corneal ring segment extrusion

Poster Details

First Author: R.Calvo SPAIN

Co Author(s):    V. Castro   B. Moratal   L. Hernandez   E. Cervera           

Abstract Details

Purpose:

Intrastromal corneal ring segments (ICRSs) constitute a substantial evolution in the management of keratoconus. Although uncommon, major complications have been described including corneal perforation, infection, migration of the implant and corneal haze or melting. Our objetive is to propose High Definition optical coherence tomography (HD- OCT) as an effective and secure technique in the management of ICRS migration. The capability of OCT images of in vivo differentiation of both corneal layers and ICRS enable better clinical decision to conduct more accurate planning of treatment in this type of complication.

Setting:

Retrospective case report of ICRS extrusion followed with HD- OCT in a patient with keratoconus at Hospital General Universitario de Valencia.

Methods:

A 34 year-old men complained for 4 weeks epiphora and foreign body sensation on his right eye. A 120º 6mm and 300µ ICRS had been implanted inferiorly for keratoconus 6 months ago. At baseline, his best corrected visual acuity (BCVA) was 20/25 with K139.71 at 124º, K244.56 at 34º and a maxK of 47.9. Slit- lamp examination (SLE) revealed a corneal irregular surface with epithelial breakdown. An implant extrusion was supposed and HD- OCT was performed. Manually measures revealed the position of the implant only at 60µ depth in its nasal zone.

Results:

Therapeutic contact lens and topical moxifloxacino three times a day was instaured. Fifteen days later, patient referred improvement of symptons and BCVA and Pentacam suggested a recovery in refractive error with K141.53 at 178º, K244.62 at 88º and maxK of 47.8. However, HD- OCT examination showed progression in the extrusion with 30µ of tissue above the implant. ICRS removal was performed. Final examination revealed a BCVA of 20/30 without correction; K143.57 at 158º, K247.60 at 68º and a maxK of 54.2. SLE and HD- OCT scan showed no signs of epithelial breakdown or haze.

Conclusions:

Keratoconus is a slowly progressive, noninflammatory ectatic corneal disease. ICRSs are inserted deep into the corneal stroma to achieve central flattening of the surface. Slit beam distortion by the implant as well as the scattering by some types of rings may difficult the estimation of depth with SLE. The 3mm 512x128 anterior segment cube of HD- OCT has been recognized as a noninvasive corneal imaging modality that enables visualization of corneal anatomic features and pathologic corneal abnormalities. In patients with ICRS it provides a precise assessment for segment depth- related complications, becoming an useful device for planning surgery.

Financial Disclosure:

NONE