COMPARISON OF CORNEO-SCLERAL AND MINI-SCLERAL CONTACT LENSES IN PATIENTS WITH PELLUCID MARGINAL DEGENERATION
Published 2026 - 30th ESCRS Winter Meeting
Reference: PO049 | Type: Presented Poster & Poster | DOI: 10.82333/fh48-5k11
Authors: Ali Ayatollahi* 1 , Mohammad Hajiebrahimi 2 , Jahangir Ayatollahi 3 , Maryam Dashti 4 , Amirhossein Mirfendereski 5
1Optometry,Shahid Beheshti University of Medical Sciences,Tehran,Iran, Islamic Republic Of;Optometry,Shahid Beheshti University of Medical Sciences,Tehran,Iran, Islamic Republic Of, 2Javadi Eye Hospital,Tehran,Iran, Islamic Republic Of, 3Ophthalmology,Yazd university of medical sciences,Yazd,Iran, Islamic Republic Of, 4Optometry,Shahid Beheshti University of Medical Sciences,Tehran,Iran, Islamic Republic Of, 5Novindidegan Eye Clinic,Tehran,Iran, Islamic Republic Of
Purpose
Pellucid marginal degeneration (PMD) is characterized by peripheral corneal thinning and high irregular astigmatism, leading to significant visual impairment. Scleral lens designs, including corneo-scleral and mini-scleral lenses, have recently emerged as effective options for visual rehabilitation in these patients. This study aimed to compare visual performance, contrast sensitivity, tear film status, and patient comfort between these two lens types over a three-month follow-up period
Setting
This study was conducted in 2025 in Tehran, Iran.
Methods
In this prospective clinical trial, 72 eyes from 72 PMD patients were randomly assigned to receive either corneo-scleral lenses (n = 36) or mini-scleral lenses (n = 36). Best-corrected visual acuity (BCVA, logMAR), contrast sensitivity at spatial frequencies of 3, 6, and 12 cpd, tear film metrics (Schirmer test, TBUT, and fluorescein staining), and patient comfort using the OSDI questionnaire and a 0–10 comfort score were evaluated at baseline and three months after lens fitting. Statistical significance was set at p < 0.05.
Results
Both groups showed a statistically significant improvement in BCVA after lens fitting (p < 0.001). However, the mini-scleral group demonstrated a superior visual outcome with a mean logMAR BCVA of 0.24 ± 0.07, compared to 0.32 ± 0.09 in the corneo-scleral group (p = 0.01). Contrast sensitivity was also significantly higher with mini-scleral lenses across key spatial frequencies, particularly at 6 cpd (p = 0.004).
Regarding ocular surface parameters, no significant difference was found in Schirmer values between the two groups (p = 0.38). Nevertheless, TBUT was significantly longer in the mini-scleral group (8.3 ± 2.4 seconds vs. 6.8 ± 2.0 seconds; p = 0.02), and fluorescein staining scores were lower, indicating better epithelial protection (p = 0.03).
Patient-reported comfort outcomes favored the mini-scleral lenses, with a notably higher mean comfort score (8.4 ± 1.1 vs. 7.1 ± 1.4; p < 0.001) and a significantly lower OSDI score (22.9 ± 5.8 vs. 28.5 ± 6.7; p = 0.008).
Conclusion
Both corneo-scleral and mini-scleral lenses provide substantial visual improvement in PMD patients. However, mini-scleral lenses offer superior optical quality, tear film stability, and overall comfort after three months of wear. They may therefore represent the preferred option for individuals with advanced irregular astigmatism caused by PMD.