Abstract
Purpose :
Intraocular pressure (IOP) may vary due to various physiological and environmental factors. As questions about IOP related to scleral lens wear are being explored, non-traditional IOP measurements are needed. While previous studies have measured IOP immediately after removing scleral lenses, both diaton and peripheral pneumotonometry are capable of measuring IOP during scleral lens wear without contacting the cornea. The purpose of this study was to compare these two methods of IOP measurement which could be used during scleral lens wear.
Methods :
There were 20 normal participants with no history of ocular disease or scleral lens wear included in this study. Five male and 15 female participants age 29 ± 9 (mean + SD) years (range, 22-57 years) had IOP measurements made on the left eye. IOP was measured using peripheral pneumotonometry (Model 30 Classic, Reichert, Inc., Buffalo, NY) followed by measurements with a Diaton transpalpebral tonometer (BiCom, Inc., Staten Island, NY). Measurements were repeated in a head tilt position with both instruments, as is recommended for Diaton, and were also completed in normal, forward facing head posture with the pneumotonometer to assess potential postural changes in IOP. Three IOP measurements were taken and averaged for each method. Mean IOP with each method was compared using paired t-tests.
Results :
Average baseline IOP with the Diaton was 7.5 + 1.9 mmHg. IOP using the pneumotonometer in matching head posture was 26.7 + 5.1mmHg and with the pneumotonometer in standard head posture was 27.5 + 5.4mmHg. A paired t-test comparing the pneumotonometry IOP measurements with standard head posture to the head tilt head posture were not significantly different (P=0.3), indicating that head posture is not likely contributing to a difference in IOP measurements with this instrument. Paired t-tests comparing IOP measured using Diaton to IOP measured with peripheral pneumotonometry with matching head posture was significantly different (P<0.005), as well as in comparison to pneumotonometry with normal head position (P<0.005).
Conclusions :
Controlling for head position, IOP measured with the Diaton and IOP measured with the pneumotonometer were not comparable in this study. Methods for studying IOP in the peripheral eye need to be standardized before determination of whether scleral lenses influence eye pressure can be definitively evaluated.
This is a 2020 ARVO Annual Meeting abstract.