Longitudinal Evaluation of the Distribution of Intraretinal Hyper-Reflective Foci in Eyes with Intermediate Age-Related Macular Degeneration

Abstract

Purpose

Intraretinal hyper-reflective foci (IHRF) are optical coherence tomography (OCT) risk factors for progression of age-related macular degeneration (AMD). In this study we assess the change in the number and distribution of IHRF over two years.

Methods

The axial distribution of IHRF were quantified in eyes with intermediate AMD (iAMD) at baseline and 24 months, using a series of 5 sequential equidistant en face OCT retinal slabs generated between the outer border of the internal limiting membrane (ILM) and the inner border of the retinal pigment epithelium (RPE). Following thresholding and binarization, IHRF were quantified in each retinal slab using ImageJ. The change in IHRF number in each slab between baseline and month 24 was calculated.

Results

Fifty-two eyes showed evidence of IHRF at baseline, and all continued to show evidence of IHRF at 24 months (M24). The total average IHRF count/eye increased significantly from 4.67 ± 0.63 at baseline to 11.62 ± 13.86 at M24 (p < 0.001) with a mean increase of 6.94 ± 11.12 (range: - 9 to + 60). Overall, at M24, 76.9% eyes showed an increase in IHRF whereas 15.4% of eyes showed a decrease (3 eyes [5.7%] showed no change). There was a greater number of IHRF and a greater increase in IHRF over M24 in the outer slabs.

Conclusions

IHRF are most common in the outer retinal layers and tend to increase in number over time. The impact of the distribution and frequency of these IHRF on the overall progression of AMD requires further study.

Keywords:

• Age-related macular degeneration
• intraretinal hyper-reflective foci
• optical coherence tomography
• retinal pigment epithelium

Authors’ contributions

AV, MGN, YH, GC, MN, SBV, JLH, MAPV, DS, SRS were responsible for designing the review protocol, writing the protocol, and report, conducting the search, screening potentially eligible studies, extracting and analyzing the data, interpreting results, updating reference lists, creating ‘Summary of findings’ tables, contributed to the design and conducting in depth analysis.

Financial disclosures

AV, YH, MNG, MN, JLH, MAP-V, DS: None; GC: Nidek (speaker fee); SRS: Consultant/Advisor: 4DMT; Alexion; Allergan, Inc.; Alnylam Pharmaceuticals; Amgen Inc; Apellis Pharmaceuticals, Inc., Astellas; Bayer Healthcare Pharmaceuticals; Biogen; Boerhinger Ingelheim; Carl Zeiss Meditec; Catalyst Pharmaceuticals Inc; Centervue, Inc.; GENENTECH; Gyroscope Therapeutics; Heidelberg Engineering; Iveric Bio; Janssen Pharmaceuticals, Inc.; Merck & Co., Inc.; Nanoscope; Novartis Pharma AG; Optos, Inc.; Oxurion/Thrombogenics; Pfizer, Inc.; Regeneron Pharmaceuticals, Inc.; Samsung Bioepis; Vertex Pharmaceuticals Incorporated. Lecture Fees/Speakers Bureau: Carl Zeiss Meditec; Heidelberg Engineering; Nidek Incorporated; Novartis Pharma AG; Topcon Medical Systems Inc.; Grant Support: Carl Zeiss Meditec; Heidelberg Engineering

Disclosure statement

No conflicting relationships exist for any author.

Data availability statement

Authors agree to make data and materials supporting the results or analysis presented in their paper available upon reasonable request. The data is not publicly available at present as this is an ongoing clinical study.

Additional information

Funding

Amish Eye Study, supported by NEI grants R01EY023164 and 1R01EY030614.