Time course of corneal oedema during modern scleral contact lens wear

Purpose To quantify the magnitude and time course of changes in central corneal thickness over an 8 hour period of open eye modern scleral contact lens wear. Methods Fifteen young healthy adults (mean age 22 ± 3 years, 8 females and 7 males) with healthy corneae and no contraindications to contact lens wear were fitted with a highly oxygen permeable 16.5 mm diameter miniscleral contact lens (Dk 100, minimum centre thickness 300 µm). A high resolution optical coherence tomographer with anterior segment module was used to capture serial central corneal thickness measurements during scleral lens wear (with the lens on eye) at 0, 15, 30, 45, 60, 90, 120, 240, and 480 minutes after lens insertion. A 6 mm x 12 radial line protocol was used centred on the reflex from the anterior contact lens surface. OCT data were exported for analysis in order to determine the central corneal thickness (at the normal to the anterior cornea) at each time point using customised software to segment the anterior and posterior corneal boundaries using a semi-automated procedure with manual correction of any segmentation errors by an experienced observer. A repeated measures ANOVA was used to examine the change in central corneal thickness over time with a least significant difference adjustment for multiple comparisons. Results Central corneal thickness varied over time (p Conclusion Corneal oedema induced during modern scleral contact lens wear in young participants with healthy corneae plateaued after approximately 1 hour of lens wear (1% swelling), and reduced slightly between 4 and 8 hours of lens wear (by 0.3%). Despite a significantly thicker post-lens tear film, the time course of corneal oedema induced during modern scleral lens wear is similar to that described previously for soft contact lenses