Analysis of neuroretinal rim distribution and vascular pattern in eyes with presumed large physiological cupping: a comparative study

Abstract

BackgroundTo investigate possible differences in neuroretinal rim distribution, vascular pattern, and peripapillary region appearance between eyes with presumed large physiological optic disc cupping (pLPC) and eyes with minimal optic disc excavation.MethodsWe prospectively enrolled consecutive subjects with pLPC and individuals with minimal excavation (optic disc excavation within normal limits; control group). All eyes had normal visual fields and untreated intraocular pressure (IOP) <21 mmHg. Eyes with pLPC required vertical cup-to-disc ratio (VCDR) ≥0.6 and ≥30 months of follow-up with no evidence of glaucomatous neuropathy. For controls, VCDR was limited to ≤0.5. We compared ocular signs and characteristics related to the neuroretinal rim distribution, vascular pattern, peripapillary region appearance and disc size between groups. Whenever both eyes were eligible, one was randomly selected for analysis.ResultsA total of 74 patients (mean age, 45.6 ± 14.9 years) with pLPC and 45 controls (mean age, 44.8 ± 11.6 years) were enrolled (p = 0.76). Median disc size and VCDR was significantly larger in eyes with pLPC compared to controls (p < 0.01). The proportion of eyes with violation of the ISNT rule, laminar dot sign, nasal shifting of the central vessels, nasal excavation and baring of circumlinear vessel was significantly greater in the eyes with pLPC compared to controls (p < 0.01). There were no significant differences regarding the proportions of eyes with peripapillary atrophy between groups (p < 0.09). Finally, disc size was significantly associated with VCDR (r2 = 0.47, p < 0.01), with an increase of 0.21 in VCDR for each 1 mm2 in disc area.ConclusionCompared to normal controls, eyes with pLPC may present a higher proportion of optic nerve head findings frequently observed in glaucomatous eyes. This seems to be explained in part by the larger discs found in these eyes. We believe care should be taken while classifying them as glaucomatous or not based solely on these characteristics.

Lack of association between provocative test-based intraocular pressure parameters and functional loss in treated glaucoma patients

“…The included patients had to have glaucomatous optic neuropathy associated with characteristic VF defects and open angle on gonioscopy. Glaucomatous optic neuropathy was defined as a vertical cup-to-disc ratio (VCDR) ≥0.6, VCDR asymmetry ≥0.2 between eyes, and localized or diffuse peripapillary retinal nerve fiber layer defects, and/or neuroretinal rim defects without any other abnormalities to explain such findings (18,19) . All VFs were measured using the 24-2 Swedish Interactive Threshold Algorithm (Humphrey Field Analyzer II, Carl Zeiss Meditec, Inc., Dublin, CA, USA).…”

Are optic discs with large physiological cups really healthy?

“…LPC was described in Lopes et al. 's [1] report as a vertical cup‐to‐disc ratio ≥ 0.6, normal visual field testing in both eyes, and at least 30 months of follow‐up with no evidence of progressive optic neuropathy (assessed using serial color stereophotographs performed at least twice a year, with a maximum interval of 6 months) prior to spectral domain optical coherence tomography (OCT) imaging. Because of these mistakes, 20% of cases are misdiagnosed glaucoma as illustrated in studies and this is not a low rate given the other pathologies leading to cupping [2].…”

“…However, if the eye is not healthy, an early diagnosis opportunity of an existing disease can be missed. The most challenging cases for clinicians are individuals with LPC, normal intraocular pressure, and visual field, and there are no existing guidelines that explain what sort of management is to be used for these cases [1].…”

Lamina Cribrosa Depth is Associated With the Cup-to-Disc Ratio in Eyes With Large Optic Disc Cupping and Cup-to-Disc Ratio Asymmetry

“…[6][7][8][9] There are few specific management guidelines for subjects with an optic disc features suspicious of glaucoma, particularly a high CDR, in contrast to the robust longitudinal data reported on ocular hypertension. [10][11][12] At the time of diagnosis, it is difficult to determine whether a patient has a very early-stage preperimetric glaucoma or simply a large physiological optic disc cup. 12 With regard to the pathogenesis of glaucomatous optic neuropathy, the laminar region of the optic nerve head (ONH) is the primary site of retinal ganglion cell (RGC) axonal injury in glaucoma.…”

“…[10][11][12] At the time of diagnosis, it is difficult to determine whether a patient has a very early-stage preperimetric glaucoma or simply a large physiological optic disc cup. 12 With regard to the pathogenesis of glaucomatous optic neuropathy, the laminar region of the optic nerve head (ONH) is the primary site of retinal ganglion cell (RGC) axonal injury in glaucoma. 13,14 The lamina provides structural and functional support to the RGC axons.…”