Posters

Treatment of progressive keratoconus with intrastromal installation of riboflavin solution

Poster Details

First Author: T.Tazhibaev KYRGYZSTAN

Co Author(s):    M. Medvedev   N. Esengeldieva           

Abstract Details

Purpose:

The research aims to evaluate the midterm results in patients with keratoсonus after the procedure of cross-linking with introstromal instillation of riboflavin solution.

Setting:

Nathional Hospital, Kyrgyz Republic

Methods:

The procedure of cross-linking with introstromal instillation of riboflavin solution has been trialed on 34 eyes of 47 patients with keratoconus: I stage —10 eyes (29%), II stage — 12 eyes (35%), III stage — 2 eyes (5,8%). Follow up period: 12 months. All patients before and after the surgery were determined for visual acuity without correction (uncorrected visual acuity) and the maximum spectacle correction (corrected visual acuity), refraction and cornea refractivity on the Anterior Segment Analyzer Nidek OPD-scan (Japan). Corneal thickness over its entire area was evaluated by using an optical coherent tomograph «OCT Cirrus HD» by Carl Zeiss (Germany) The procedure of corneal collagen cross-linking was performed under dropping anesthesia. We made an introstromal instillation of Dextralink solution in 4 quadrants during 15 minutes with 2-4 minutes interval. Further the irradiation of the cornea was performed with a UV LED wavelength of 360 nm. Prerequisite procedure is to measure the thickness of the cornea in the center 1) before the procedure, 2) after removal of the epithelium 3) after instillation solution 'Dextralink' and 4) after irradiation. Observations were made in postoperative period every 1,3,6,16 months.

Results:

The next day after the corneal collagen cross-linking all patients reported blurred vision and a presence of light mist before the eye. A week later, visual acuity began to improve, blurring effect disappeared. In the early days after the corneal collagen cross-linking while observing through the slit lamp the swelling of the outer layers of the stroma was noted in all cases. At the reexaminations during the month a slight sub-epithelial corneal opacity in the center, in a diameter of 3-4 mm was noted on 7 eyes. By three months after the corneal collagen cross-linking, in all cases, the cornea was clear. Analysis of the results of corneal collagen cross-linking on stages of keratoconus revealed no differences in the parameters shown in the table. All optometric and functional parameters have stabilized by three months observations after the cross-linking treatment and remained for 16 months after the procedure. The corneal thickness in the center of 4 patients slightly (for 10-15 microns) decreased due to concretion of the corneal tissue, which was confirmed by pachymetry. Postoperative complications were as follows:

Conclusions:

Сross-linking with introstromal instillation does not differ from the normal procedure. But in some cases, in patients with a thin cornea it is possible to apply procedures improving functional performance with I-III stage of keratoconus. Little experience with cornea collagen cross-linking (34 eyes) and the period of observation (12 months) do enable to assume that it stops the progression of keratoconus, as all progress indicators were preserved 12 months after the corneal collagen cross-linking. Furthermore, confocal microscopy showed a significant increase in the density of the extracellular matrix of the stroma, which was an indirect indicator of improving the biomechanical properties of the cornea. FINANCIAL INTEREST: NONE