Article Sidebar
Main Article Content
Abstract
Background: Corneal ectasia is characterized by high-order aberrations and irregular astigmatism, presenting significant optical challenges. Scleral lenses neutralize these irregularities via a post-lens tear reservoir. However, the precise optical contribution of the tear reservoir thickness itself to residual refractive error remains under-characterized, particularly in Southeast Asian populations where aggressive ectasia phenotypes are common. This study aimed to determine if tear reservoir thickness correlates with residual refractive error using vector analysis.
Methods: This retrospective pilot study analyzed 12 eyes of 8 patients with severe corneal ectasia fitted with scleral lenses in Indonesia. Refractive outcomes were converted to Thibos power vectors (M, J0, J45). To account for bilateral eye correlations, linear mixed models (LMM) were employed with Patient ID as a random effect. A theoretical thick-lens model compared predicted versus observed over-refraction.
Results: The cohort (mean age 28 ± 10.2 years) achieved significant visual improvement (LogMAR 0.35 to 0.17; p = 0.005). The mean tear reservoir thickness was 263.33 ± 80.92 μm. LMM analysis revealed no statistically significant correlation between fluid thickness and Spherical Equivalent (M) (beta = -0.001, p = 0.72) or Blur Strength (p = 0.68). The theoretical model indicated that residual error was driven by uncorrected posterior corneal astigmatism rather than fluid depth.
Conclusion: In this Indonesian cohort, optical efficacy was driven by refractive index matching at the corneal interface, not reservoir thickness. Clinical fitting should prioritize physiological clearance over refractive manipulation.
Keywords
Article Details
As our aim is to disseminate original research article, hence the publishing right is a necessary one. The publishing right is needed in order to reach the agreement between the author and publisher. As the journal is fully open access, the authors will sign an exclusive license agreement.
The authors have the right to:
- Share their article in the same ways permitted to third parties under the relevant user license.
- Retain copyright, patent, trademark and other intellectual property rights including research data.
- Proper attribution and credit for the published work.
For the open access article, the publisher is granted to the following right.
- The non-exclusive right to publish the article and grant right to others.
- For the published article, the publisher applied for the Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.
