A recent study based in Japan suggests measuring corneal changes, such as posterior corneal depression and epithelial thickening, might have a larger impact on reduced contrast sensitivity than on BCVA in Fuchs’ endothelial corneal dystrophy (FECD) patients. The impact of the disease on the patient is usually judged by measuring high contrast visual acuity; however, this measurement may not predict the patient’s visual performance or fully reﬂect the qualitative visual disturbance, which can often be debilitating. The team of researchers noted contrast sensitivity is a useful tool for assessing visual dysfunction and could benefit future grading systems for the condition.
The team investigated a total of 101 eyes of 61 patients (18 male and 43 female) with FECD. Contrast sensitivity was measured with the Pelli-Robson contrast sensitivity test. They evaluated corneal alterations, including central corneal thickness, posterior corneal depression and corneal densitometry, using Scheimpflug imaging. They also measured corneal epithelial thickness with SD-OCT.
The Spearman rank correlation coefficient showed moderate correlation between BCVA and contrast sensitivity (ρ=-0.66), with some patients maintaining relatively good BCVA but exhibiting reduced contrast sensitivity. The researchers noted that this discrepancy might explain the clinical observation that some patients experience life activity difﬁculties despite their good BCVA.
Logistic regression analysis demonstrated that age, central corneal thickness, posterior corneal depression and epithelial thickening were negatively associated with contrast sensitivity but not with BCVA.
The study determined that the Pelli-Robson contrast sensitivity test—a highly repeatable, accurate, inexpensive and rapid test—can be adopted in standard clinical settings to capture reduced vision in patients with FECD.
“Including these measurements [of corneal changes] in the clinical protocol would enhance our ability to assess the true severity of the disease and could form the basis of a new grading system in the future,” the researchers concluded. “This, in turn, would facilitate the creation of appropriate treatment algorithms based on objective parameters that could reﬁne our approach to the management of FECD.”
Okumura N, Padmanaban V, Balaji J, et al. Clinical, morphological and optical correlates of visual function in patients with Fuchs’ endothelial corneal dystrophy. Cornea. August 6, 2021. [Epub ahead of print].