Skip to main content

  • ICD-10 Glaucoma Grade May Underestimate the Damage

    By Lynda Seminara
    Selected by Richard K. Parrish II, MD
    Add to My Bookmarks

    Journal Highlights

    American Journal of Ophthalmology, December 2022

    Download PDF

    The ICD-10 system for classifying glau­coma severity is based on the location of visual field (VF) defects. The size and depth of perimetric defects are not included in the ICD-10 guidance for grading glaucoma. Given the poor sensitivity of the 24-2 test for detect­ing early-stage glaucoma and macular damage, Leshno et al. hypothesized that the current ICD codes may not represent the full extent of glaucoma­tous damage. In their retrospective analysis of the validity and reliability of the ICD-10 system in relation to OCT findings, a large number of eyes with macular structural damage were missed by 24-2 VF testing alone.

    The authors began their study by collecting data for participants of the Macular Damage in Early Glaucoma and Progression Study. Independent glaucoma experts who were unaware of the purpose of the study reviewed data for all eyes that received OCT, disc photography, and 24-2 VF testing performed within a six-month period. The masked experts assigned an ICD-10 severity grade based on 24-2 VF and were asked to specify which regions contained defects (i.e., superior/inferior hemifield, superior/inferior central five degrees). Other masked examiners independently determined the presence of OCT-displayed structural damage in the same regions.

    Overall, 80 eyes were evaluated. Based on 24-2 VF testing, the glau­comatous optic neuropathy (GON) was classified as advanced in 42 eyes, moderate in 23 eyes, and mild in 15 eyes. According to OCT findings, GON severity was higher overall: advanced in 67 cases, moderate in seven, and mild in six. OCT showed greater severity for 29 eyes (36%). In 33 eyes (41.3%), the macular damage detected by OCT was missed by the 24-2 test. In four eyes (5%), 24-2 VF testing overestimated the severity, which may be due to the variability of this test, said the authors.

    Based on these findings, OCT revealed a wider extent of damage across all grades and was able to identify macular structural damage missed by 24-2 VF testing. The ICD-10 system is an indicator of VF severity rather than glaucoma severity, said the authors, who called for clarification of the system’s rationale. They believe that adding OCT data to the ICD-10 system would more accurately define the extent of glaucomatous damage. “If central involvement is to be considered a sign of severe glaucoma, it is possible to modify the current system to better assess it,” they said.

    The original article can be found here.