Scleral lens fenestrations and fluid reservoir debris

Authors: 
Damien Fisher¹, Luisa Holguin Colorado¹, David Alonso-Caneiro^1,2, Stephen J Vincent¹

Affiliations: 
1 Centre for Vision and Eye Research, Optometry and Vision Science, Queensland University of Technology, Brisbane, Australia
2 School of Science, Technology and Engineering, University of Sunshine Coast, Petrie, Australia

Funding:
This research was funded by a CooperVision Science and Technology Award.

Conflict of interest:
The authors report no conflicts of interest and have no proprietary interest in any of the materials mentioned in this article.

ABSTRACT

Purpose: The accumulation of debris within the fluid reservoir during scleral lens wear (midday fogging) is a common occurrence with multiple potential aetiologies and can adversely affect vision resulting in the need for lens removal. The aim of this study was to quantify the effect of incorporating scleral lens fenestrations upon fluid reservoir debris.

Methods: Twenty young healthy adults with normal corneas wore non-fenestrated and fenestrated (3 x 1 mm limbal fenestrations separated by 120º) OneFitMed+ scleral lenses in both eyes (on separate days) for three hours. All other scleral lens parameters were held constant except for the addition of the fenestrations. Customised image analysis was used to quantify central fluid reservoir debris (an average and total debris metric) from Scheimpflug images of the right eye captured during lens wear. Central fluid reservoir thickness and corneal oedema was quantified using optical coherence tomography.

Results: 
Fluid reservoir debris increased over time (p < 0.001), more so for non-fenestrated lenses. After 3 hours of lens wear, the total debris metric was greater for non-fenestrated lens design (166 ± 21 vs 111 ± 9 arbitrary units, p < 0.01). The presence of an air bubble within the fluid reservoir for the fenestrated lenses had impact on debris (p = 0.80). There was no association between central corneal oedema and the fluid reservoir debris metrics for either the fenestrated (R² ≤ 0.08, p ≤ 0.28) or non-fenestrated lenses (R² ≤ 0.001, p ≤ 0.90).

Conclusions: 
Non-fenestrated lenses displayed ~2-4 times more central fluid reservoir debris than fenestrated lenses after three hours of lens wear, when controlling for confounding variables. This suggests a potential role for fenestrated lens designs in managing fluid
reservoir debris and midday fogging during scleral lens wear, however longer term studies including participants with ocular disease are required.