Classifying Ectopia Lentis in Marfan Syndrome into Five Grades of Increasing Severity

To describe a five-grade classification of ectopia lentis in Marfan syndrome (MFS) and to evaluate the positive predictive value of the early grades of ectopia lentis.

We prospectively included MFS patients and their healthy relatives. The anterior segment examination was classified into grades 0 to 5, and we studied the sensitivity, specificity, and positive predictive value of ectopia lentis in this classification.

Seventy-four MFS patients and thirty-six healthy controls were examined. In the MFS group, grades 1, 2, 3, and 4 were present in 15, 24, 17, and 7 patients, respectively, whereas 11 patients in this group did not present ectopia lentis. In the control group, grades 0 and 1 were observed in 30 and 6 individuals, respectively. Sensitivity to ectopia lentis of at least grade 2 was 64.9%, with 100% specificity, whereas sensitivity to ectopia lentis of at least grade 1 was 85.1%, with 83.3% specificity. The positive predictive value of ectopia lentis that was greater than or equal to grade 2 was 100%, whereas that of ectopia lentis greater than or equal to grade 1 was 91.3%.

High positive predictive values s were found to be associated with grades 2 and higher of the five-grade classification of ectopia lentis. This classification should help to harmonize clinical practices for this major feature of MFS.