Relative Peripheral Refraction Quantitative Method Shows Promise

Multispectral refractive tomography (MRT) may be a useful tool for assessing relative peripheral refraction (RPR), according to a study published in Photodiagnosis and Photodynamic Therapy. 

Researchers conducted an analysis to determine a relationship between RPR and retinal microvasculature in young adults. They included 278 eyes of 139 participants in the study (mean age 26.51±3.82 years, 100 women, 131 with myopia) and performed ophthalmic exams, MRT, optical coherence tomography-angiography (OCT-A) imaging, and obtained intraocular pressure (IOP) and axial length measurements. An Analysis of variance (ANOVA) test determined refraction difference values (RDVs) in different rings of the eye. 

Investigators noted the 30°-45°/45°-53° RDV was significantly greater than the inner rings in both eyes (0.63±0.64, 0.71±0.61, P =.035 and 1.09±0.93, 1.28±0.95, P <.001 for the OD and OS, respectively), and they witnessed an increase in RPR from the inner to outer rings. Furthermore, RDV in the superior sector (0.19±0.91, 0.34±0.88, P =.003, OD and OS, respectively) was most significantly reduced among all sectors, while RDV in the nasal sector (1.00±0.82, 0.92±0.82, P =.11, OD and OS, respectively) was significantly greater than that in the temporal sector (0.44±0.81, 0.71±0.77, P <.001, OD and OS, respectively). They also observed RDV was negatively associated with both radial peripapillary capillary plexus density and macular thickness using stepwise multiple linear regression analysis. 

Investigators highlight the shortcomings of the current methods of RPR assessment: “Major objective optometry, including retinoscopy, photoretinoscopy, autorefraction and aberrometry, is usually adopted under various specific head and eye positions. In addition, the low accuracy of retinal location and a limited VOF [view of field] (less than 40°) may restrict the clinical application to a degree.”

However, they paint a hopeful picture using novel MRT technology: “MRT can quantitatively measure RPR in a wide VOF (53°) as well as in specific retinal sectors with a single shot and without various specific eye positions. The results are automatically output and intelligible.”

Study limitations include a failure to assess peripheral axial length and OCT-A images.  

Reference

Li Z, Yang Z, Liao Y, et al. Relative peripheral refraction characteristics and their relationship with retinal microvasculature in young adults: using a novel quantitative approach. Photodiagnosis Photodyn Ther. Published online February 5, 2022. doi:10.1016/j.pdpdt.2022.102750