Effect of subthreshold nanosecond laser on retinal structure and function in intermediate age‐related macular degeneration

• Published in: Clinical & experimental ophthalmology Vol. 50; no. 1; pp. 31 - 39
• Main Authors: Gunawan, Josephine R., Thiele, Sarah H., Isselmann, Ben, Caruso, Emily, Guymer, Robyn H., Luu, Chi D.
• Format: Journal Article
• Language: English
• Published: Melbourne John Wiley & Sons Australia, Ltd 01.01.2022; Wiley Subscription Services, Inc
• Subjects: Acuity; age‐related macular degeneration; Eye; Fluorescein Angiography; Humans; Lasers; Macular degeneration; Macular Degeneration - complications; Macular Degeneration - diagnosis; Macular Degeneration - surgery; Pilot Projects; Prospective Studies; relative ellipsoid zone reflectivity (rEZR); Retina; retinal thickness; rod‐mediated function; Structure-function relationships; subthreshold nanosecond laser treatment; Tomography, Optical Coherence; retinal thickness; relative ellipsoid zone reflectivity (rEZR); age-related macular degeneration; rod-mediated function; subthreshold nanosecond laser treatment
• ISSN: 1442-6404; 1442-9071; 1442-9071
• DOI: 10.1111/ceo.14018

Background Subthreshold nanosecond laser (SNL) treatment has been studied as a potential intervention in intermediate age‐related macular degeneration (iAMD). This study investigated the effect of 100 SNL treatment spots on retinal structure and function. Methods A prospective single‐arm interventional pilot study. SNL treatment was delivered as 100 spots around the retinal vascular arcades of the study eye (worst visual acuity) in a single session in subjects with iAMD. Multimodal retinal imaging and dark‐adapted chromatic perimetry were performed at baseline and at 0.5, 3, 6 and 12 months post treatment. Post treatment changes in best corrected visual acuity (BCVA), retinal thickness, relative ellipsoid zone reflectivity (rEZR) and rod‐mediated functional parameters were compared to baseline. Results Twenty‐one subjects with iAMD were recruited. SNL treatment was associated with an increase in retinal thickness (p = 0.008) and decrease in rEZR (p < 0.001) at 2 weeks post laser. Recovery of retinal thickness and rEZR was observed at the 3‐month post laser visit. A gradual improvement in BCVA was observed after laser treatment. The mean change in BCVA between baseline and 12‐month visit was +1.9 ± 3.3 letters for the SNL treated eyes, compared to −0.4 ± 3.0 letters for the fellow eyes (p = 0.027). Rod‐mediated function improved at 3 months post laser (p < 0.001) and returned to the baseline levels at 12 months post treatment. Conclusions A single treatment with 100 SNL spots causes a short‐term change in retinal structure and improvement in retinal function that are apparent at 3 months post treatment.