Juvenile-onset open-angle glaucoma - A clinical and genetic update.

Juvenile-onset open-angle glaucoma (JOAG) is a subset of primary open-angle glaucoma that is diagnosed before 40 years of age. The disease may be familial or non-familial, with proportions varying among different populations. Myocilin mutations are the most commonly associated. JOAG is characterized by high intraocular pressures (IOP), with many patients needing surgery. The mean age at diagnosis is in the 3rd decade, with a male preponderance. Myopia is a common association. The pathophysiology underlying the disease is immaturity of the conventional outflow pathways, which may or may not be observed on gonioscopy and anterior segment optical coherence tomography. The unique optic nerve head features include large discs with deep, steep cupping associated with high IOP-induced damage. Progression rates among JOAG patients are comparable to adult primary glaucomas, but as the disease affects younger patients, the projected disability from this disease is higher. Early diagnosis, prompt management, and life-long monitoring play an important role in preventing disease progression. Gene-based therapies currently under investigation offer future hope.

The high-pressure bleb.

A 45-year-old male presented with a slowly progressive, painless swelling in his right eye for the past 6 months. He had undergone an open globe injury repair 10 years back and an eventful cataract surgery 5 years back. The presenting visual acuity in the affected eye was perception of light with inaccurate projection of rays. The intraocular pressure was 44 mm Hg with advanced glaucomatous cupping. The swelling was identified to be a communicating sub-tenon cyst secondary to scleral wound dehiscence from secondary angle closure glaucoma. Wound re-suturing, cyst excision and diode laser cyclophotocoagulation was performed in a single sitting, with explained poor visual prognosis.

Clinical, ultrasonographic and optical coherence tomography correlation of optic nerve head cupping in glaucoma patients.

Purpose: To ascertain if ultrasound (USG) B-scan examination of the optic nerve head (ONH) can be a useful tool to diagnose and quantify glaucomatous cupping. Methods: A cross-sectional observational study of 48 eyes of 48 patients with clear ocular media and cup-disc ratio of (CDR) ≥0.6 were included. The disc was studied by + 90D examination, USG B-scan and ONH Optical coherence tomography (OCT) by three masked observers. Observer-1 assessed the clinical CDR, observer-2recordedopticcup diameter on USG B-scan and observer-3performed ONH OCT to note the software computed average CDR. Measurements of cupping obtained by these 3 methods were compared and their relative strengths determined. The interdependency between variables was further studied using regression analysis. Results: Clinically assessed disc ratios of 0.6, 0.7, 0.8, 0.9, and total corresponded to USG cup measures of 1.02 ± 0.11 mm, 1.23 ± 0.14 mm, 1.35 ± 0.072 mm, 1.45 ± 0.084 mm, 1.75 ± 0.15 mm and OCT average CDR of 0.62 ± 0.087, 0.68 ± 0.060, 0.75 ± 0.078, 0.81 ± 0.036, 0.89 ± 0.038, respectively. There was an excellent correlation between the three arms, with Pearson's co-efficient (r) of 0.87, P < 0.001 between clinical and USG cupping; r = 0.89, P < 0.001 between clinical and OCT cupping; and r = 0.88, P < 0.001 between USG and OCT cupping. A relation of y = 1.64x + 0.03 was obtained between them, where y stands for USG cup diameter and x stands for the observed clinical CDR. Conclusion: Ultrasonographic measurement of optic cup diameter corresponds well to clinical ONH cupping. Therefore, it can reliably be used in quantifying ONH cupping in cases of media opacities which preclude optic disc visualization.