Bilateral nonarteritic anterior ischemic neuropathy following acute angle-closure glaucoma in a patient with iridoschisis: case report

Abstract

A 55-year-old woman was referred to our clinic because of a one-week history of visual loss and raised intraocular pressure in the left eye followed 4 days later by visual loss in the right eye. Slit-lamp examination showed bilateral conjunctival hyperemia, slight diffuse corneal edema, shallow anterior chamber and fixed and dilated pupil in both eyes. Splitting of the anterior layers of the iris with fibrillar degeneration extending for approximately one quadrant inferiorly was presented in each eye. Fundus examination showed opitc disc edema with no vascular tortuosity and no cup in both eyes. The condition was treated as bilateral acute angle-closure glaucoma in a patient with irisdoschisis. After medical treatment and improvement of visual acuity, perimetry revealed a significant visual field defect especially in left eye; this case represents a rare concurrence of acute angle-closure glaucoma and bilateral nonarteritic ischemic optic neuropathy. Although most cases of elevated intraocular pressure, including acute angle-closure glaucoma, do not result in optic disc edema and irreversible vision loss, variations in the vascular supply of the nerve optic head along with others ocular systemic risk factors, may predispose certain individuals to nonarteritic ischemic optic neuropathy during periods of elevated intraocular pressure. Keywords

Nonarteritic anterior ischemic optic neuropathy following pars plana vitrectomy for macular hole treatment: case report

“…Since both IOP and venous pressure are increased in the prone position, the combination of these two events may precipitate ischemia of the anterior portion of the optic nerve, resulting in NAION. Although we documented only a moderate increase in IOP in the present case, IOP may have reached a much higher level before examination and thereby contributed to the development of NAION (8) . The association between face-down position and increased IOP is well described, notably in low-light conditions, and can be used in clinical practice as a provocative test for angle-closure glaucoma (7) .…”

Iridoschisis—A Systematic Review

“…Corneal changes are uncommon and, if present, the degenerated corneal endothelial cells are mostly localized above the area of iridoschisis [ 20 , 21 , 22 , 23 , 24 , 25 ]. Visual deterioration is usually caused by glaucoma, cataract or corneal decompensation secondary to iridocorneal touch [ 26 ].…”

“…The authors of another interesting published case report described a patient with simultaneous bilateral nonarteritic anterior ischemic optic neuropathy (NAION) associated with acute ACG secondary to iridoschisis. According to the authors, elevated intraocular pressure might be the main precipitating factor for the development of NAION in their patient [ 26 ]. Iridoschisis can also coexist with plateau iris configuration [ 28 , 43 ].…”

“…Angle-closure glaucoma or angle narrowing resulting in an acute angle closure associated with iridoschisis are usually treated with peripheral laser iridotomy to relieve the pupillary block [ 5 , 19 , 20 , 26 , 28 , 47 , 48 ]. However, some authors suggested that goniosynechialysis combined with cataract removal is superior to laser peripheral iridotomy in patients with iridoschisis complicated with closed-angle glaucoma triggered by peripheral anterior synechiae [ 47 ].…”

Optic Nerve Head Elastometry in Both Eyes of Patients with Unilateral Non-arteritic Anterior Ischaemic Optic Neuropathy – May It Be a Novel Aspect of the Pathogenesis?

“…1,2 Hypertension (HT), diabetes mellitus (DM), hyperlipidaemia, sleep apnoea syndrome, and nocturnal hypotension are systemic risk factors for NAION, whereas local risk factors include acute angle closure glaucoma, raised intraocular pressure (IOP), and crowded optic disc (small disc area/small cupping). [3][4][5][6][7][8][9] Although the main risk factor for glaucomatous optic neuropathy is raised IOP, lower retrobulbar perfusion pressure, biomechanical properties of the ONH, and lamina cribrosa are also important in ischaemic neuropathy development. 10,11 In vivo measurement of the corneal biomechanical properties is possible by the ocular response analyser (ORA, Reichert Ophthalmic Instrument, Depew, NY, USA); however, direct measurement of the ONH biomechanics is not possible yet.…”