ESCRS - PO301 - The Effect Of Thickness, Degree And Types Of Segmental Intrastromal Corneal Rings On Visual And Refractive Outcomes In Keratoconus Patients.

The Effect Of Thickness, Degree And Types Of Segmental Intrastromal Corneal Rings On Visual And Refractive Outcomes In Keratoconus Patients.

Published 2022 - 40th Congress of the ESCRS

Reference: PO301 | Type: ESCRS 2022 - Posters | DOI: 10.82333/xs42-pq55

Authors: Hesam Hashemian* 1 , Zahra Moravvej 2 , Mehdi Khodaparast 1 , Kiyanoush Shahraki 1 , Shiva Sabour 1 , Sogol Olamazadeh 1 , Fateme Alipour 1

1Translational Ophthalmology Research Center, Farabi Eye Hospital,Tehran University of Medical Sciences,Tehran,Iran, Islamic Republic Of, 2Department of Ophthalmology, Hakim Hospital,Neyshabur University of Medical Sciences,Neyshabur,Iran, Islamic Republic Of

Purpose

To evaluate and compare different Keraring arc lengths and thicknesses regarding visual acuity and refraction results.

Setting

This study was done at Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran.

Methods

This prospective cohort study was performed on 68 keratoconic eyes of 68 patients. Keraring (Mediphacos, Belo Horizonte, Brazil) is a ring segment with different arc lengths and thickness ranging from 150 to 350 μm. The inner and outer KeraRing diameters are 5 and 5.8-6.0 mm, respectively. All patients underwent comprehensive ophthalmic evaluation including dry manifest refraction, UDVA and CDVA, slit-lamp examination, preop and 3 months postop. The eyes were divided into three groups based on Keraring thickness: 200 μm (20 patients), 250 μm (18 patients), and 300 μm (30 patients) and then different visual and refractive parameters were assessed. The patients were also divided based on arc degree: 160° (52 patients) and 210° (14 patients).

Results

Visual acuity and refraction improved in all cases 3 months after surgery. In 160-degree group UDVA and CDVA improved from 0.81 ± 0.41 and 0.35 ± 0.14 to 0.70 ± 0.39 and 0.28 ± 0.17 respectively. Similar results were seen in 210-degree group, and 200, 250 and 300 μm groups. Results of different ring thicknesses and arc lengths were compared, and no statistical significance was observed. The amount of correction of UDVA (UDVApre – UDVApost) was significantly better in 250 μm group. But this result was not correlated to better vision in this group of patients.

Conclusions

Despite progress in corneal ring treatments for keratoconus and different designs available, it is not clear what rings arc lengths and thicknesses are the better choice for keratoconus patients and more investigation is warranted to elucidate the optimum design of corneal rings for keratoconus patients.