Purchase this article with an account.
Teruhiko Hamanaka, Tetsuro Sakurai, Nobuo Ishida, Nobuo Fuse, Toshio Kumasaka; Developmental abnormalities of outflow routes in POAG patients. Invest. Ophthalmol. Vis. Sci. 2020;61(7):3420.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
We previously reported that in primary open-angle glaucoma (POAG) patients, age-related Schlemm’s canal (SC) endothelium (SCE) drop out results in diminishing the size of the SC (Hamanaka T et al. IOVS 2016:57:692), thus indicating that the SC in younger POAG patients may be less influenced by aging. Here we investigated characteristics that may lead to the development of trabecular meshwork and SC abnormalities in POAG patients ≤40 years old using trabeculectomy specimens.
This study involved 41 trabeculectomy specimens of 34 POAG patients ≤40 years old (Group A) and 10 trabeculectomy specimens of 10 POAG patients 70-79 years old with no familial history of POAG in the first generation (Group B, control) that underwent immuno-histological examination stained with CD34 and thrombomodulin to detect SCE, and hematoxylin & eosin. In each specimen, light microscopy photographs were used to investigate the SC length (SCL), the percentage of thrombomodulin or CD34 negative area (PTNA) of SCE, the estimated original SC length (OSCL) by measuring SC length in addition to the occluded SC area which shows fibrosis, and the percentage of SC occlusion (PSCO: OSCL-SCL/OSCLx100%). Moreover, podoplanin staining patterns in the trabecular meshwork were investigated to analyze aqueous-flow activity.
In Group A and Group B, the mean SCL, PTNA, OSCL and PSCO were 222±68μm and 180±87μm (P=0.1807), 20.33±24.38% and 11.30±15.42% (P=0.171), 224±70μm and 276±41μm (P=0.007), and 0.97±3.09% and 35.9±30.49% (P=0.006) respectively. In Group A, there were 11 eyes of 8 patients with a familial history of POAG in the first generation, and 20 eyes of 16 patients with no familial history POAG in the first generation. In Group A, SC abnormalities were observed in some of the eyes, and there was much less podoplanin staining in the juxta-canalicular meshwork (JCT) compared with the eyes in Group B. However, in those eyes, it was difficult to differentiate those with a familial history of POAG from those with no familial history of POAG.
Our findings show that SC abnormalities in elderly POAG subjects may be due to aging, and strongly suggest the development of SC and JCT abnormalities in POAG subjects less than 40 years old. However, further study in needed to elucidate whether the development of SC and JCT abnormalities is due to genetic-related factors or other reasons.
This is a 2020 ARVO Annual Meeting abstract.
This PDF is available to Subscribers Only