Interobserver variability in the estimation of the cup/disk ratio among observers of differing educational background

Accurate assessment of the cup/disk (C/D) ratio is an important skill for eyecare practitioners. Interobserver variability in this estimation has been documented in many studies. This study compares the estimate variation in the C/D ratio as judged by five groups with different educational backgrounds who would provide patient care at a college of optometry.

Third- and fourth-year students, optometry residents, attending optometrists, and attending ophthalmologists evaluated the C/D ratios of 20 optic nerves using stereoscopic optic nerve photographs. There were five observers in each group, for a total of 25 participants. The results were statistically analyzed with a one-way analysis of variance and the Duncan multiple range test.

The one-way analysis of variance showed that a statistically significant difference existed among the five groups. Further analysis with the Duncan multiple range test showed that the attending optometry group was significantly different from the third-year student, fourth-year student, and attending ophthalmology groups. Also, the optometry resident group estimates were significantly different than the fourth-year student and attending ophthalmology group estimates.

There was a statistically significant difference in the estimation of the C/D ratio using stereoscopic disk photographs among five groups that had different educational backgrounds.