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Glaucomatous Optic Nerve Atrophy with Enlarged Foveolar Avascular Zone in Juvenile Primary Open Angle Glaucoma (Colour Photography Posterior Pole, Triton OCT, Triton OCT-A, VF)Glaucomas -> Primary Chronic Open Angle Glaucoma40 years of age, female, BCVA 1.0 at OD, 1.0 at OS, IOP 14/15 mmHg under topical therapy.
Ocular Medical History: since 20 years glaucoma, now IOP values lower 16 mmHg with topical prostglandins, slowly progressing glaucomatous optic nerve atrophy, constant visual acuity, peripherial visual field defects.
General Medical History: no events reported.
Main Complaint: visual field defects in OS.
Purpose: to present progressed optic nerce atrophy with increased area of foveolar avascular zone.
Methods: Colour Photography Posterior Pole, Triton OCT, Triton OCT-angiography, visual field Octopus G1 .
Findings:
Visual Field, OD: peripherial scotoma (MD 1.8 dB).
Visual Field, OS: peripherial scotoma (MD 5.5 dB).
Colour Photography Posterior Pole, OD: glaucomatous optic nerve atrophy (disc area 2.05 mm², rim area 0.05 mm², C/D-ratio 0.99).
Colour Photography Posterior Pole, OS: glaucomatous optic nerve atrophy (disc area 2.26 mm², rim area 0.15 mm², C/D-ratio 0.97).
Triton OCT, retinal nerve fiber thickness, OD: highly thinned retinal nerve fiber layer (total 19µm).
Triton OCT, retinal nerve fiber thickness, OS: highly thinned retinal nerve fiber layer (total 22µm).
Triton OCT-angiography, retina, superficial retinal layer, OD: no relevant loss of capillary meshwork
Triton OCT-angiography, retina, deep retinal layerOD: no relevant loss of capillary meshwork.
Triton OCT-angiography, retina, superficial retinal layer, OS: increased area of foveolar avascular zone.
Triton OCT-angiography, retina, deep retinal layerOS: : increased area of foveolar avascular zone.
Discussion: Primary open-angle glaucoma (POAG) is characterized by progressive degeneration of retinal ganglion cells and their axons, resulting in structural damage to the optic nerve head (ONH) and inner retina. Approximately half of these retinal ganglion cells are located within 4.5 mm of the center of the fovea. The superficial capillaries mainly nourish the ganglion cell layer. Penteado RC (1) evaluated in 185 eyes the association between macula vascular density assessed by optical coherence tomography angiography (OCT-A) and central visual field (VF) threshold sensitivities in healthy, glaucoma suspect, and glaucoma patients. He found that severe glaucoma subjects had significantly lower macula vessel density values compared with early glaucoma or healthy eyes. They reported that glaucoma eyes generally had sparser macula capillary networks compared with healthy eyes, glaucoma suspects, or mild glaucoma eyes. They documented an average macula vessel density for healthy eyes of 52.5%±3.7%, and for moderate/severe glaucoma patients of 45.2%±3.9%. Macula OCT-A may be an important adjunctive tool for identifying subjects at risk for developing glaucoma.
Literature:
1. Penteado RC, Zangwill LM, Daga FB, Saunders LJ, Manalastas PIC, Shoji T, Akagi T, Christopher M, Yarmohammadi A, Moghimi S, Weinreb RN. Optical Coherence Tomography Angiography Macular Vascular Density Measurements and the Central 10-2 Visual Field in Glaucoma. J Glaucoma. 2018 Jun;27(6):481-489. -------------------------- -------------------------- -------------------------- -------------------------- -------------------------- -------------------------- -------------------------- -------------------------- -------------------------- -------------------------- -------------------------- -------------------------- |