# Analysis and optimization of the landing zone parameters of a sclera lens model

## TL;DR

This study modifies scleral contact lenses to improve fitting effectiveness and reliability in patients with keratoconus.

## Contribution

A novel adjustment method for scleral contact lenses was proposed and shown to be effective and reproducible.

## Key findings

- The proposed adjustment achieved 93.5% correct lens delivery with no baseline compression.
- Interrater agreement among experts ranged from 68.8% to 80.9%.
- The method proved practical for scleral lens adaptation in keratoconus patients.

## Abstract

This study aimed to modify scleral contact lenses to achieve a desired
compression standard and to evaluate the effectiveness and reliability of
the adjustments.

In this nonrandomized, noncomparative, and partially masked study Scleral
contact lens fittings were analyzed in 20 eyes of 12 patients (50% women,
50% men) diagnosed with keratoconus. Participants were selected based on
their need for scleral contact lenses (SCLs), which was determined in
complete ophthalmological examinations. Patients were tested with Zenlens
scleral contact lenses (Bausch & Lomb, Vaughan, Ontario, Canada). We
evaluated compression in the lens support area after one hour of use,
excluding cases of peripheral lifting. Photos of the adaptations were sent
to five experts for analysis of the quadrants (nasal, temporal, superior,
and inferior). We used Fisher’s exact test for statistical analysis.

The proposed adjustment was highly effective (93.5% correct) in lens delivery
(BL=0), with the interrater agreement between doctors ranging from 68.8% to
80.9%.

The clinical parameters proposed for scleral contact lenses adjustment proved
useful and reproducible, enabling their practical application to scleral
lens adaptation.