Fluctuations in retinal thickness may equate to a poor prognosis for wet AMD patients treated with anti-VEGF therapy, a study in JAMA Ophthalmology reports.

The investigation included 1,731 previously untreated wet AMD participants from the Comparison of Age-Related Macular Degeneration Treatments Trials (CATT) and the Inhibition of VEGF in Age-Related Choroidal Neovascularization (IVAN) randomized clinical trial.

The researchers measured the foveal center point thickness of 1,165 eyes from CATT and 566 eyes from the IVAN trial, excluding those with less than four measurements. For each eye, the study calculated the average change of the foveal center point thickness, and eyes were grouped by thickness quartiles:

• Quartile one: less than 34.01μm
• Quartile two: 34.01μm to less than 51.49μm
• Quartile three: 51.49μm to less than 80.59μm
• Quartile four: greater than 80.59μm

At the 24-month follow up or the patient’s last visit, the researchers looked at associations between retinal thickness measurements, best-corrected visual acuity (BCVA) and the development of fibrosis and macular atrophy.

Patients were mainly female (61.1%) and were about 79 years old. The median change in the foveal center point thicknesses was 40.2 in the IVAN cohort and 59.0 in the CATT cohort.

After adjusting for baseline BCVA and trial allocations, BCVA worsened significantly as the change in retinal thickness increased; the difference between the first and fourth quartiles was –6.27 ETDRS letters.

Additionally, the study reported that the risk of developing fibrosis and macular atrophy also increased the more the foveal center point thicknesses varied. Odds ratios ranged from 1.40 for quartile two to 1.95 for quartile four for fibrosis, and from 1.32 for quartile two to 2.10 for quartile four for macular atrophy.

The findings provide an impetus for clinicians to seek agents with greater treatment durability or sustained-release devices, such as those currently undergoing evaluation, the researchers noted in their paper.

Practitioners may want to consider retinal thickness variations when advising patients about their prognosis, they added.