Virtual Reality Hemifield Measurements for Corrective Surgery Eligibility in Ptosis Patients: A Pilot Clinical Trial

Abstract

Purpose We developed an accelerated virtual reality (VR) suprathreshold hemifield perimetry algorithm, the median cut hemifield test (MCHT). This study examines the ability of the MCHT to determine ptosis severity and its reversibility with an artificial improvement by eyelid taping on an HTC Vive Pro Eye VR headset and the Humphrey visual field analyzer (HVFA) to assess the capabilities of emerging technologies in evaluating ptosis. Methods In a single visit, the MCHT was administered along with the HVFA 30-2 on ptotic untaped and taped eyelids in a randomized order. The primary end points were a superior field visibility comparison with severity of VF loss and VF improvement after taping for MCHT and HVFA. Secondary end points included evaluating patients’ Likert-scaled survey responses on the comfort, speed, and overall experience with both testing modalities. Results VR's MCHT superior field degrees visible correlated well for severe category margin to reflex distance (r = 0.78) compared with HVFA's (r = −0.21). The MCHT also demonstrated noninferiority (83.3% agreement; P = 1) against HVFA for detection of 30% or more superior visual field improvement after taping, warranting a corrective surgical intervention. In comparing hemi-VF in untaped eyes, both tests demonstrated relative obstruction to the field when comparing normal controls to severe ptosis (HVFA P < 0.05; MCHT P < 0.001), which proved sufficient to demonstrate percent improvement with taping. The secondary end point of patient satisfaction favored VR vision testing presentation mode in terms of comfort ( P < 0.01), speed ( P < 0.001), and overall experience ( P < 0.01). Conclusions This pilot trial supports the use of MCHT for the quantitative measurement of visual field loss owing to ptosis and the reversibility of ptosis that is tested when conducting a presurgical evaluation. We believe the adoption of MCHT testing in oculoplastic clinics could decrease patient burden and accelerate time to corrective treatment. Translational Relevance In this study, we look at vision field outputs in patients with ptosis to evaluate its severity and improvement with eyelid taping on a low-profile VR-based technology and compare it with HVFA. Our results demonstrate that alternative, portable technologies such as VR can be used to grade the degree of ptosis and determine whether ptosis surgery could provide a significant superior visual field improvement of 30% or more, all while ensuring a more comfortable experience and faster testing time.

Clinical report: Virtual reality enables comparable contrast sensitivity measurements to in-office testing (pilot study)

“…Because no preliminary studies exist for accurate utility of Bland-Altman sample size calculation method, we used a Student t test power analysis with significance level set to 5%, an effect size for Cohen d of 80%, and a statistical power of 80%. The estimated minimum number of participants needed to power this experiment was 25 participants 15–18 . Accordingly, 28 participants were recruited for testing on a voluntary basis with informed consent and with randomization of the sequence of modality.…”

“…Poor contrast sensitivity is a responsive indicator of a variety of eye pathologies including, but not limited to, cataracts, 7,8 keratoconus, 9,10 central epithelial corneal defects, 11 cystoid macular edema, 12 and even central serous chorioretinopathy 13,14 . Despite growing virtual reality adoption in optometry, no head-to-head clinical trials have been performed to date comparing the direct outputs of in-office Pelli-Robson testing with a virtual reality analog, although efforts to make custom contrast tests for virtual reality have recently started 15 . Clinical validations in the virtual reality environment are essential because digital factors such as scaling, illumination, and pixel density can drastically affect the accuracy of results.…”

“…13,14 Despite growing virtual reality adoption in optometry, no head-to-head clinical trials have been performed to date comparing the direct outputs of in-office Pelli-Robson testing with a virtual reality analog, although efforts to make custom contrast tests for virtual reality have recently started. 15 Clinical validations in the virtual reality environment are essential because digital factors such as scaling, illumination, and pixel density can drastically affect the accuracy of results.…”

“…The estimated minimum number of participants needed to power this experiment was 25 participants. [15][16][17][18] Accordingly, 28 participants were recruited for testing on a voluntary basis with informed consent and with randomization of the sequence of modality. The inclusion criteria consisted of adults 18 years and older who were able to provide informed consent.…”