Adding Personalized Wavefront Correction to a Scleral Lens After Lens Manufacture

PURPOSE: To date, wavefront-guided scleral lenses have relied on the full-surface method (FSM) of manufacture, which requires the wavefront correction to be integrated into the design of a traditional scleral lens prior to lens manufacture. A novel patch-cutting method (PCM) of manufacture would rely on carving the wavefront correction into the anterior surface of a previously manufactured scleral lens. This study assessed the accuracy of cutting wavefront corrections with both the FSM and PCM. METHOD: Four wavefront-guided scleral lens designs were chosen for evaluation in this study. Two duplicates of 4 unique wavefront-guided scleral lens designs were manufactured using both the FSM and PCM, resulting in a total of 16 test lenses. All lenses were optically profiled and the aberrations were represented with a 2nd-10th radial order Zernike polynomial. Total dioptric difference (TDD) and change in higher order RMS wavefront error (HO-RMS WFE) were calculated between each wavefront-guided lens and its design, its within-method of manufacture duplicate, and across methods of manufacture. TDD was compared to the clinical step size of 0.25 D and HO-RMS WFE was compared to the average amount of HO-RMS WFE in the typical 20–29-year-old eye, 0.433 µm, over a 7 mm pupil. RESULTS: All 16 lenses exhibited TDD and ΔHO-RMS WFE below the benchmark when compared to their design and to each other. Average and standard deviation in TDD between the first and second builds of the FSM and PCM lenses were 0.071 ± 0.044 D and 0.149 ± 0.077 D, respectively. Results showed no statistically significant difference in the TDD between the FSM and PCM (p= 0.13). Average and standard deviation of ΔHO-RMS WFE between the first and second build of the FSM and PCM lenses were 0.139 ± 0.036 µm and 0.133 ± 0.075 µm, respectively. Results showed no statistically significant difference in the ΔHO-RMS WFE between the FSM and PCM (p=0.89). Manufacturing tolerances were established as follows: 95% CI for TDD [0.050 D, 0.170 D] and 95% CI for ΔHO-RMS WFE [0.091 µm, 0.182 µm]. CONCLUSIONS: Utilizing the PCM does not induce variability in the manufacturing process beyond what is already observed in the FSM.

Name thesis:degree_name

Master of Science

Discipline thesis:degree_discipline

Physiological Optics and Vision Science

Grantor

University of Houston

Year dc:date.issued

2026

Author dc:creator

• Elam, Evan S 1999-

Advisor dc:contributor.advisor

• Marsack, Jason

Committee members dc:contributor.committeemember

• Ritchey, Eric
• Walker, Maria

• Keratoconus
• Scleral contact lens
• Wavefront
• Manufacturing

Language dc:language.iso

English

Handle dc:identifier.uri

https://hdl.handle.net/10657/21601

OAI identifier oai:identifier

oai:uh-ir.tdl.org:10657/21601