Tested in a pilot study
In a collaboration with colleagues at the Kellogg Eye Center, University of Michigan, Ann Arbor, Dr. Miller’s research team tested the computerized contrast testing device in a pilot study of retinal detachment. Fifteen patients were included and underwent testing of their contrast sensitivity function during their postoperative recovery.
Patients with significant cataract or a history of multiple retinal detachment repairs were excluded. The testing, which offers the use of filtered Sloan letters with 128 possible contrast and 19 possible spatial frequencies, was performed at an average 6 months after the reattachment surgeries, Dr. Miller pointed out.
“In this prospective, observational multicenter case series study, we found a 2 standard deviation difference in the contrast function after retinal attachment compared with age-matched controls,” Dr. Miller explained. “More importantly, this testing device, compared with Pelli-Robson contrast testing, showed that at different spatial frequencies there were relatively large differences. This device allows us to measure at the different spatial frequencies and pick up stronger signals at the intermediate frequencies that had not been detectable with previous technology.”
While the investigators found a difference in the contrast function of 2 standard deviations of all the patients tested, 9 of the 15 patients had a best-corrected visual acuity (BCVA) at 20/30 or better. However, despite the good vision, these patients had a difference in contrast function of 1 standard deviation.
“In patients with good visual acuity, we still found statistically significant contrast function reductions,” Dr. Miller added. “This provides us with a greater clinical signal of functional vision for testing of new therapeutics when visual acuity may otherwise show minimal effects.
“This device provides an efficient, user friendly, smart algorithm to measure the contrast function curve that can be used with a variety of retinopathies,” Dr. Miller said. “Additional work must be performed to validate our findings but could represent a new endpoint for visual function.”