Retinal Thickness Variation Linked to Other Outcomes for nAMD Patients

August 21, 2020

The risk of developing fibrosis and macular atrophy increased based on which quartile of foveal center point thickness standard deviation an individual falls in.

New research shows a number of outcomes for patients with neovascular age-related macular degeneration (nAMD) are directly related to the retinal thickness variations following the initiating of anti-vascular endothelial growth factor (anti-VEGF) treatment.

A team, led by Rebecca N. Evans, MSc, Clinical Trials and Evaluation Unit, Bristol Trials Centre, Bristol Medical School, University of Bristol, investigated whether visual and anatomic outcomes in eyes with neovascular age-related macular degeneration initiating anti-VEGF treatment are linked to fluctuations in retinal thickness.

When initiating anti-VEGF treatment for patients with nAMD, prognostic factors often guide specific treatments. The investigators believe eyes with greater fluctuation in retinal thickness over time have worse outcomes than eyes with less variation.

The investigators used data from the Comparison of Age-Related Macular Degeneration Treatment Trials (CATT), as well as the Inhibition of VEGF in Age-Related Choroidal Neovascularization (IVAN) randomized clinical trial. The study included patients with previously untreated nAMD.

The team extracted foveal center point thicknesses (FCPTs) from 1165 study eyes from CATT and 566 study eyes from the IVAN trial, excluding those with 3 measurements or less. They then calculated the standard deviation of FCPT for each eye.

Ultimately eyes were grouped by FCPT SD quartile and associations with FCPT standard deviation quartile with outcomes were quantified at month 24 or the last available visit by linear or logistic regression, adjusting for baseline best-corrected visual acuity (BCVA) and randomized allocations to drug and treatment regimen, for BCVA, development of fibrosis, and the development of macular atrophy.

A total of 1731 patients were included in the final analysis, 1058 of which were female. The mean age of the patient population was 78.6 years old and the median FCPT SD was 40.2 in the IVAN cohort and 59.0 in the CATT cohort.

After the investigators adjusted for baseline BCVA and trial allocations, BCVA worsened significantly across the quartiles of FCPT standard deviation.

Overall, the difference between the first and fourth quartiles was -6.27 Early Treatment Diabetic Retinopathy Study letters (95% CI, -8.45 to -4.09).

They also found the risk of developing fibrosis and macular atrophy increased across FCPT SD quartiles. The odds ratios ranged from 1.40 (95% CI, 1.03-1.91) for quartile 2 to 1.95 (95% CI, 1.42-2.68) for quartile 4 for fibrosis. The OR also ranged from 1.32 (95% CI, 0.90-1.92) for quartile 2 to 2.10 (95% CI, 1.45-3.05) for quartile 4 for macular atrophy.

“Greater variation in retinal thickness in eyes with nAMD during treatment with anti-VEGF was associated with worse BCVA and development of fibrosis and macular atrophy in these post hoc analyses, despite protocol-directed treatment frequency,” the authors wrote. “Practitioners may want to consider variation in retinal thickness when advising patients about their prognosis.”

The study, “Associations of Variation in Retinal Thickness With Visual Acuity and Anatomic Outcomes in Eyes With Neovascular Age-Related Macular Degeneration Lesions Treated With Anti–Vascular Endothelial Growth Factor Agents,” was published online in JAMA Ophthalmology.