Regional Variations in Postlens Tear Layer Thickness During Scleral Lens Wear

Stephen J. Vincent; David Alonso-Caneiro; Michael J. Collins

doi:10.1097/ICL.0000000000000676

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Regional Variations in Postlens Tear Layer Thickness During Scleral Lens Wear

Journal article

Peer reviewed

Regional Variations in Postlens Tear Layer Thickness During Scleral Lens Wear

Stephen J. Vincent, David Alonso-Caneiro and Michael J. Collins

Eye and Contact Lens, Vol.46(6), pp.368-374

2020

DOI: https://doi.org/10.1097/ICL.0000000000000676

PMID: 31724975

Abstract

scleral lens

postlens tear layer

corneal clearance

Objectives: To quantify regional variations in the postlens tear layer (PLTL) thickness during scleral lens wear. Methods: Fifteen healthy adults (22 +/- 3 years) with normal corneae were fitted with a 16.5-mm-diameter rotationally symmetric scleral lens in one eye. The PLTL thickness was measured across the central 5 mm at 0, 15, 30, 45, 60, 90, 120, 240, and 480 min after lens insertion using a 12 radial line scan optical coherence tomography imaging protocol. Regional analyses were conducted by dividing the PLTL into 8 equal 45 degrees segments. Results: A tilted optic zone was observed immediately after lens insertion with the greatest PLTL asymmetry between nasal and temporal regions (156 +/- 22 mu m more clearance temporally) and superior nasal and inferotemporal regions (124 +/- 12 mu m more clearance inferotemporally). The magnitude of lens settling observed in each region was associated with the initial PLTL (r=0.59-0.77, P <= 0.02). The superior nasal PLTL furthest from the pupil center stabilized after 90 min compared with other regions which stabilized after 4 hr. On average, after 8 hr of lens wear, the PLTL decreased by 29% and PLTL asymmetries between opposing regions decreased by 30%. Conclusions: The PLTL was thickest temporally and thinnest nasally in healthy eyes fitted with rotationally symmetric scleral lenses, most likely because of regional differences in underlying scleral elevation, eyelid forces, and lens centration. Postlens tear layer asymmetries diminished with lens wear, and stabilization occurred more rapidly in regions with less corneal clearance immediately after lens insertion.

Details

Title: Regional Variations in Postlens Tear Layer Thickness During Scleral Lens Wear
Authors: Stephen J. Vincent (Corresponding Author) - Queensland University of Technology
David Alonso-Caneiro (Author) - Queensland University of Technology
Michael J. Collins (Author) - Queensland University of Technology
Publication details: Eye and Contact Lens, Vol.46(6), pp.368-374
Publisher: Lippincott Williams & Wilkins
DOI: 10.1097/ICL.0000000000000676
ISSN: 1542-233X
PMID: 31724975
Grant note: Queensland University of Technology, Institute of Health and Biomedical Innovation, Vision and Eye Development Grant
Organisation Unit: School of Science, Technology and Engineering
Language: English
Record Identifier: 99972398502621
Output Type: Journal article