Characteristics of pigmentary glaucoma in Japanese individuals

PURPOSE: Myopia is a known risk factor of pigmentary glaucoma (PG), and the increased prevalence of myopia in Asian countries indicates that more cases of PG will likely develop soon. However, there are no diagnostic criteria for PG for Asians. Therefore, the purpose of this study is to determine the characteristics of PG in Japanese individuals and establish three diagnostic signs for PG. METHODS: This was a single-center, retrospective, case series study of glaucoma patients who visited the Kagoshima University Hospital between January 2015 and January 2020. The inclusion criteria were age <50 years at time of diagnosis and presence of pigmentation in the anterior chamber (AC) angle including a Sampaolesi line. Eyes with pigmentation of the AC angle caused by other types of glaucoma such as uveitis, trauma, exfoliation, or childhood glaucoma were excluded. We investigated the classic diagnostic triad of signs of PG; posterior corneal pigmentation, mid peripheral iris transillumination defect, and pigmentation of the trabecular meshwork. We also examined the Sampaolesi line, iris concavity, and midperipheral iris depigmentation in eyes with PG. RESULTS: Ten eyes of 5 Japanese men and 10 eyes of 5 Japanese women were studied. Their age ranged from 13 to 46 years at the time of diagnosis. One eye had posterior corneal pigmentation and 6 eyes had pigmentation of the trabecular meshwork. None had mid peripheral iris transillumination defect. The Sampaolesi line, iris concavity, and midperipheral iris depigmentation were found in all patients except one patient who lacked the mid peripheral depigmentation. Two eyes had the pigment reversal sign, none had lens pigmentation, and 2 eyes had peripheral retinal degeneration. CONCLUSION: The presence of the Sampaolesi line, iris concavity, and midperipheral iris depigmentation may be appropriate signs for the diagnosis of PG in Asians.