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Between the time a patient with neovascular age-related macular degeneration (AMD) pauses monthly injections and the time that they are evaluated for potential retreatment, the area of choroidal neovascularization (CNV) may continue to expand. New research using optical coherence tomography angiography (OCT-A) imaging shows that enlargement of the CNV area during the treatment-free period and CNV features, such as the presence of branching with tiny vessels and peripheral arcade at the CNV termini, may guide the requirement for additional administration of anti vascular endothelial growth factor (VEGF) agents in eyes with exudative-free periods during long-term treatment.
In prior research, investigators have been able to identify that a certain number of eyes will need re-treatment. A study from the National Health Service in the UK found that after treatment-free intervals of 6 months and 12 months, 44% and 21% of eyes, respectively, required re-treatments after an additional 6 months of follow-up.
The same study shows that, after 12 months of follow-up, 56% and 34% of those eyes, respectively, required re-treatment. The new study published in Retina sought to establish predictors for which patients would require re-treatment using OCT-A.
The researchers examined OCT-A images of 41 eyes of 41 patients. The subjects had all undergone more than 3 years of anti-VEGF therapy for neovascular AMD at the study’s baseline. Thereafter, they had a treatment-free period of more than 6 months under an as-needed regimen, and researchers were able to follow them for an additional 6 months.
The investigation found that CNV reactivation may be predicted in eyes with a history of long-term treatment if OCT-A images display a branching vascular aspect with numerous tiny vessels and peripheral arcade at the CNV termini. This differs from the traditional “lacy wheel” or “sea fan” shape of well-defined CNV lesions.
Researchers measured the square root of the CNV area in the 41 study eyes (2.31 mm ± 1.01 mm) at baseline and found no significant changes at the final examination (2.59 mm ± 1.18 mm). The shape of the CNV was defined as a “lacy wheel” or “sea fan” in 19 (46%) eyes. However, during the follow-up period, 11 (27%) eyes had a branching vascular aspect with numerous tiny vessels; 9 (22%) eyes had peripheral arcade at the CNV termini; and 17 (41%) eyes had prominent central vessels.
Based on recurrent exudative changes during the follow-up period, 19 (46%) eyes comprised the recurrence group, and 22 (54%) eyes comprised the cessation-of-activity group. The square root of the CNV area in the recurrence group enlarged significantly (P =.036) from 2.31 mm (± 0.81 mm) to 2.86 mm (± 0.87 mm) during the follow-up period (7.9 ± 1.5 months), whereas the baseline square root of the CNV area of 2.38 mm (± 1.32 mm) in the cessation-of-activity group did not change significantly (2.45 mm ± 1.53 mm) at the last examination (follow-up period, 12.4 ± 0.7 months).
The percentages of eyes with branching with tiny vessels and peripheral arcades at the CNV termini were significantly higher in the recurrence group compared with the cessation-of-activity group, whereas no significant differences were found in the percentages of eyes with a “lacy wheel” or “sea fan-shaped” CNV or prominent central vessels between the 2 groups.
The investigators speculate that these features of CNV morphology that are associated with lesion reactivity may be used to help identify high-risk lesions for treatment before recurrence of the exudative changes or the development of irreversible vision loss.
One of the authors of this study has a financial relationship with Carl Zeiss Meditec Co, Ltd, Tokyo, Japan. Please see the original reference for a full list of authors’ disclosures.
Reference
Hikichi T, Agarie M, Kubo N, Yamauchi M. Predictors of recurrent exudation in choroidal neovascularization in age- related macular degeneration during a treatment-free period. Retina. 2020;40(11):2158-2165. doi: 10.1097/IAE.0000000000002745
