Keratometry and axial length in pigment dispersion syndrome: A descriptivecase-control study

Purpose: Pigment dispersion syndrome and pigmentary glaucoma are characteri zed by loss of pigment from the posterior surface of the iris due to revers e pupillary block. This may be due to an anomalous relation between the pos ition of the globe within the orbit, the axial length of the globe, and the corneal curvature. The authors compared axial length, keratometry, and exo phthalmometry in patients with pigment dispersion syndrome and pigmentary g laucoma and in healthy controls. Methods: Thirteen pigment dispersion syndrome and pigmentary glaucoma and 1 7 controls underwent refraction, keratometry, A-scan and exophthalmometry. Patients with pigment dispersion syndrome and pigmentary glaucoma were sele cted in a university glaucoma practice, and controls were selected for thei r age and refraction from the staff of the hospital. Both groups were compa rable in age and refraction. Results: Mean age of pigment dispersion syndrome patients and healthy contr ols was 46.54 and 41.82 years (P = 0.30), respectively, and mean refraction (spherical equivalent) was -4.53 and -4.32 diopters, (P = 0.84), respectiv ely. No statistical differences were noted in axial length measured with A- scan (25.98 and 25.14, P = 0. 15) or anterior chamber depth and lens thickn ess. The pigment dispersion syndrome and pigmentary glaucoma group had flat ter keratometry than the myopic controls. Mean keratometry was 42.39 +/- 1. 77 and 44.34 +/- 1.50 (P = 0.003), respectively. Conclusion: The results show that patients with pigment dispersion syndrome have flatter keratometry of approximately 2 diopters compared with age-mat ched myopic controls. This finding suggests a difference in architecture of the anterior segment.