By Shreeya Nanda, Senior medwireNews Reporter
Progression and severity of macular atrophy are the main anatomical determinants of long-term visual outcomes in exudative age-related macular degeneration (AMD) patients treated with ranibizumab, suggest SEVEN-UP study results.
The study included 65 patients (65 eyes) treated with ranibizumab in the ANCHOR or MARINA trials who continued in the treatment arm of the open-label HORIZON trial. The SEVEN-UP participants underwent clinical evaluation and a panel of retinal imaging tests at a single update visit with the aim of identifying anatomical factors associated with visual outcomes.
At an average of 7.3 years after enrolment in the ANCHOR or MARINA trials, almost all (98%) study eyes demonstrated macular atrophy, the team reports in the American Journal of Ophthalmology.
Mean lesion area increased from 0.83 mm2 to 2.22 mm2 in the 5 years between exiting from ANCHOR or MARINA (year 2) and the SEVEN-UP visit (year 7), equating to an average growth rate of 0.28 mm2 per year.
And each 1 mm2 increase in lesion area was associated with a reduction in vision acuity of 1.6 Early Treatment Diabetic Retinopathy Study (ETDRS) letters.
Of the 56 patients for whom complete data were available, vision acuity was significantly worse in those with macular atrophy area above (n=28) compared with below (n=28) the median of 8.01 mm2, at a mean of 59.4 versus 34.2 letters.
Similarly, fewer patients in the above-median group had a final vision of 20/40 or better than those in the below-median group, at 4% and 39%, respectively.
And in 40 patients with image data available at the specific time points, macular atrophy growth above the median increase of 1.25 mm2 was associated with greater decline in vision from year 2 to year 7, at an average of –29.9 letters for participants with above-median growth compared with –13.3 for those with below-median growth.
Multivariate analysis confirmed that macular atrophy, but not other factors such as macular thinning or thickening and subfoveal fibrosis, was significantly associated with long-term visual outcomes.
Researcher Robert Bhisitkul (University of California, San Francisco, USA) and co-authors suggest that “[o]ngoing assessment of macular atrophy progression may be advisable in the management of exudative AMD patients”.
They conclude: “The findings may explain in part the disparate visual results that can be observed among treated AMD patients and underline the need for long-term studies to understand the therapeutic course of this and other chronic retinal diseases managed with intravitreal anti-[vascular endothelial growth factor] agents.”
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