[Comparison of visometry by Sivtsev and ETDRS charts]

Most foreign authors currently recommend the protocol and charts developed for the Early Treatment Diabetic Retinopathy Study (ETDRS) as the gold standard for evaluation of visual acuity (VA) in clinical trials and studies. Not every medical facility has equipment required for performing visometry by that method, while Sivtsev tables are found universally.

To compare ETDRS and the more common Sivtsev visometry methods.

The study included 100 volunteers - students of the Sechenov University. All participants were examined for VA in both eyes without correction using ETDRS "R" chart and Sivtsev table. Visometry with "R" ETDRS chart involved calculation of the number of named letters, then the number was translated into logarithmic notation by the conventional method. Sivtsev visometry findings were translated into logarithmic notation by two methods: first - standard, line-by-line, second - experimental, letter-by-letter. Subjects were divided into two groups: high VA (higher than 0.4 in decimal scale) and low VA - everyone else.

The best agreement with ETDRS was found in letter-by-letter method of Sivtsev table interpretation, especially in the group with high VA with the lowest 95% limits of agreement (LoA) of ±0.157 logMAR, or 8 letters on ETDRS. Clinically significant were also LoA in comparison of ETDRS with line-by-line calculation method in the group with high VA and in letter-by-letter method without dividing groups by VA.

The use of Sivtsev table in standardized multicenter studies is only reasonable when the ETDRS charts are unavailable.