The Influence of Race, Age, and Pupil Size on the Measurement of a Photorefraction Device
Journal Title: Journal of Ophthalmic Science - Year 2017, Vol 1, Issue 3
Abstract
Photorefraction (PR) methods have beenwidely used for pediatric vision screening since the 1980’s. While PR is easy to implement, the accuracy of refractive error measurements in humans has been unsatisfactory, largely due to the variations of intraocular scattering, the retinal reflectance, and pupil size. The objective of our studies was to clinically evaluate the accuracy of refraction measurements of an improved PR-based device, the Dynamic Ocular Evaluation System (DOES), and to investigate whether the accuracy is affected by the patient’s age, race, and pupil size, which are relevant to individual intraocular scattering and retinal reflectance. We performed DOES measurements in 99 volunteers (198 eyes) under two environmental light conditions and using four fixation targets. These results were compared to the standard clinical refraction testing performed the same day. The correlation and standard deviation were determined by Bland-Altman analysis. The influence of intraocular scattering, retinal reflectance, and pupil size was evaluated by comparing results from different age groups, races, and lighting conditions. In the region between -4 diopter (D) and +4D, the device showed a binocular refraction measurement accuracy of 0.45 D, 0.3 D, and 0.18 D root-mean-square (RMS) error (n=1337) for spherical equivalent and cross cylinders Jo and J45, respectively. Inaccuracy increased at high refraction (>4D). Age, race, and pupil size did not appear to significantly affect DOES PR measurement. This suggests that enhancements in the PR system and analysis may satisfactorily correct intersubject variability that currently limits the clinical use of PR devices and measurements.
Authors and Affiliations
Lei Shi, Ying-Ling Chen, J. W. L. Lewis
Early Versus Late Immunomodulatory Therapy in Vogt-Koyanagi-Harada disease
Purpose: To evaluate early versus late immunomodulatory therapy (IMT) for patients following initial diagnosis of Vogt-Koyanagi-Harada (VKH) disease. Methods: Retrospective review including all VKH patients seen 5/1/2...
Rapidly Progressing Visual Loss Associated with Optic Nerve Head Drusen: Is there A Role For Lowering Intraocular Pressure?
Background: Optic nerve head drusen are acellular hyaline deposits located anterior to the lamina cribrosa, frequently associated with visual field defects. Sometimes rapid worsening of vision may occur due to complicat...
Ciliary Neurotrophic Factor Activated Signaling Pathways in Retinal Müller Cells
Ciliary neurotrophic factor (CNTF) is a well-tested, neuroprotective agent that has been shown to retard photoreceptor degeneration in several animal models of retinitis pigmentosa. The molecular mechanisms underlying CN...
Superior Sclera Versus Temporal Corneal on Steep Axis Incision to Correct Pre-Existing Corneal Astigmatism Less Than 1.5 D
Purpose: Cataract is the leading cause of blindness worldwide. Even in an uneventful cataract surgery, surgically induced astigmatism remains the major hurdle in attaining good unaided visual acuity post surgery. If pre-...
Influence of Visual Impairment on The Quality of Life: A Survey of Patients Reporting at The Low Vision Centre of the Eastern Regional Hospital Of Ghana
Our aim was to evaluate the influence of visual impairment on the quality of life of patients reporting at the low vision centre of the Eastern Regional Hospital in Koforidua. The World Health Organization Quality Of Lif...