Efficacy Of Progressive Intracorneal Ring Segment Implantation In Patients With Duck And Snowman Phenotypes Of Keratoconus: Prospective Study

To evaluate the functional and anatomical corneal changes in patients with keratoconus intervened of Progressive ICRS implantation, with a diagnosis of type 2 (Duck) and type 3 (Snowman) phenotypes.

All patients had Keratoconus diagnosis, of types 2 (Duck) or 3 (snowman) phenotypes, based in the Fernandez-Vega/Alfonso morphologic Keratoconus classification. Keratometric data were analyzed with the same Galilei® topography and performed by the same technician, aswell as the visual and refractive measurements. All patients were intervened by the same group of surgeons, using the Vacuum pump for ICRS implantation (AJL Kv200).

This prospective study included 10 consecutive eyes of 8 patients (5 men and 3 women) with keratoconus diagnosis of types 2 (Duck) and 3 (Snowman) phenotypes, based in the Fernandez-Vega/Alfonso morphologic Keratoconus classification. They underwent surgical implantation of progressive ICRS AJL pro+. ICRS were implanted manually using the Vacuum pump for ICRS implantation (AJL Kv200) under topical anesthesia. The analysis include demographic and clinical data and Galilei^® topography. The measurements analyzed were: UDVA, CDVA, subjective refraction, topographic astigmatism, K1 and K2 topographic keratometry, and aberrometric coma. The data were recorded 1 week before surgery, and 1-month and 3-months after surgery.

Mean age of the patients was 22±11 years and median follow-up was 4.5months (range 3-6 months). At the end of the study a significal improvement was achieved in all patients in both UDVA (range between 2 and 10 lines of the Snellen chart) and CDVA (range between 1 and 2 lines of the Snellen chart). The topographic measurements showed decrease in both K1 and K2, with the K2 meridian showing the greatest decrease. The aberrometric measurements showed no significant decrease.

 The implantation of progressive ICRS is a safe and effective procedure in patients with a diagnosis of keratoconus with types 2 (Duck) and 3 (Snowman), with significant improvement in visual, refractive and topographic parameters.