By Nikki Withers, medwireNews Reporter
Sporadic vision loss occurs in patients with age-related macular degeneration (AMD) and impairs their future visual acuity, research shows.
Such sporadic vision loss was associated with AMD-related risk factors in some cases but there were also instances where it was associated with factors unrelated to AMD, such as a history of anxiety, a history of syncope and lack of refraction.
The researchers used data for 1185 patients from the Comparison of Age-Related Macular Degeneration Treatments Trials (CATT).
Sporadic vision loss was defined as a decline of 15 letters or more from the previous visit, followed by a return at the next visit to no more than five letters worse than the visit before the visual acuity (VA) loss.
All patients were aged 50 years or more, had untreated choroidal neovascularisation from AMD in the study eye and had a VA of 20/25–20/320 and neovascularisation or its sequelae at the foveal centre.
Led by Benjamin Kim (University of Pennsylvania, Philadelphia, USA), the researchers found that 122 (10.3%) of the patients had at least one event of sporadic vision loss over the 2 years of monthly visits.
These patients had less VA gains at 2 years than patients without sporadic vision loss, the researchers write. The average VA among patients with sporadic vision loss was 58.5 letters compared with 68.4 letters for those without sporadic vision loss; with a mean change from baseline of 3.1 letters and 6.7 letters, respectively.
Multivariate analysis revealed that patients with worse baseline vision (20/200–20/320) were 2.92-fold more likely to experience sporadic vision loss than those with better baseline vision (20/25–20/40).
Patients presenting with a scar or foveal fluid at baseline were a respective 2.21 and 1.80 times more likely to experience sporadic vision loss than those without.
Interestingly, patients with a history of a psychological disorder were 1.52 times more likely to experience sporadic vision loss than those with no history. Further analysis revealed that a history of anxiety was the driving force for this association. A syncope history was also associated with a 2.75-fold increased risk of sporadic vision loss.
“These data suggest that acute changes in mental health as well as those factors that lead to syncope may lead to sporadic vision loss”, write Kim et al in the American Journal of Ophthalmology.
They conclude: “We believe that these data are valuable for clinicians, those planning clinical trials and trial investigators.”
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