Study: VR set measures pupillary response, ocular alignment

(Image Credit: AdobeStock/insta_photos) *Image does not represent VS 2020

The VS 2020 (Twenty/Twenty Therapeutics) is a novel virtual reality headset that can provide acceptable repeatability for assessing the pupillary response and ocular alignment among patients with cataracts, according to Karim Kozhaya, MD.

Kozhaya and colleagues from Baylor College of Medicine in Houston, Texas, presented results of a study at the recent American Society of
Cataract and Refractive Surgery annual meeting in Boston, Massachusetts.

This self-guided device uses eye-tracking technology to automate entrance exams. Enabling the patients to perform the exams independently offers the potential to reduce reliance on staff for basic eye testing, thus improving efficiency, increasing patient engagement, and standardizing measurements.

Prospective study of VS 2020 capabilities

The VS 2020 includes 7 examinations, including pupillary response, unilateral cover/uncover test, alternate cover test, visual field screening, contrast sensitivity, color vision testing, and ocular mobility. Of these, the investigators were especially interested in the first 3 examinations. The rationale behind assessing the repeatability of these measurements in patients with cataracts was as follows: The pupillary response is valuable to identify afferent pupillary defects and to evaluate for IOLs that are pupillary dependent or pupils that are excessively large. The benefit of the alignment tests is to screen for a phoria that could affect the surgeon’s decision to recommend monovision.^1,2

The investigators recruited 17 cataract patients and performed 3 consecutive tests. They assessed the repeatability of the device based on the within-subject standard deviation and the repeatability limit, reporting 1 eye per patient.

Results of tests

Kozhaya reported that the repeatability for all 3 measures was good and certainly well within the needs for clinical use. The mean pupil sizes in light and dark conditions, respectively, were 2.33 mm (range, 1.67-3.00) and 3.12 mm (range, 2.10-4.17). The respective within-subject SDs were 0.04 and 0.05, and respective repeatability limits were 0.11 and 0.13.

In commenting on the relatively small pupil size under dark conditions, Kozhaya noted that this was due to performing the test in a bright room. In its second-generation headset, the company is improving the seal to better block out ambient light.

The results of the unilateral cover/uncover test showed acceptable repeatability results. The mean values in the horizontal and vertical positions, respectively, with repeatability within 1 prism diopter (D).

“The novel virtual reality headset demonstrated acceptable repeatability in measuring pupillary responses and eye alignment among patients [with cataracts],’ the authors concluded.

Future plans include recruiting more study participants, assessing the repeatability of the other 4 tests, and expanding the range of the examinations. Specifically, the team at Cullen Eye Institute at Baylor College of Medicine is collaborating with Twenty/Twenty Therapeutics to report the blink rate measurements, which are useful for patients with tear film dysfunction and for patients considering refractive surgery or implantation of multifocal IOLs.

The company is also working on incorporating more measurements, including vision testing and intraocular pressure tonometry.

Karim Kozhaya, MD

E: Karim.Kozhaya@bcm.edu

Kozhaya has no financial interest in this subject matter. This article is based on Kozhaya’s presentation of a novel virtual reality headset in assessing pupil response and eye alignment of patients with cataracts at the American Society of Cataract and Refractive Surgery Annual Meeting, April 5 to 8, 2024, in Boston, Massachusetts. Kozhaya was joined in the study by Dylan B. McBee, BSc; Saina Esfandiari, OD; Li Wang, MD, PhD; Allison J. Chen, MD, MPH; Mitchell P. Weikert, MD; and Douglas D. Koch, MD.

References:

1. Micheletti JM, McCauley MB, Duncan N, Hall B. Biometric indicators for maximizing intermediate vision with a monofocal IOL. Clin Ophthalmol. 2023;17:3739-3746. doi:10.2147/OPTH.S441172

2. Alarcon A, Canovas C, Koopman B, Pande MV, Koch DD, Piers P. Optical bench evaluation of the effect of pupil size in new generation monofocal intraocular lenses. BMC Ophthalmol. 2023;23(1):112. doi:10.1186/s12886-023-02839-y