Peripapillary Retinoschisis in Glaucoma: Association With Progression and OCT Signs of Müller Cell Involvement

Abstract

PurposeTo examine demographic and clinical factors associated with glaucomatous peripapillary retinoschisis (PPRS) and assess its association with glaucoma progression.MethodsUsing a case control study design and longitudinal data from a cohort of 166 subjects with a diagnosis of glaucoma or glaucoma suspect, we compared functional, structural, clinical, and demographic characteristics between PPRS cases and controls.ResultsThe frequency of PPRS was 6.0% (12 eyes from 10/166 subjects) with two eyes having PPRS in different sectors for a total of 15 retinoschisis events. There were no significant differences (P > 0.05) in age, sex, visual acuity, central corneal thickness, intraocular pressure, or presence of vitreous adhesion between PPRS and controls. However, eyes with PPRS tended to have a higher cup-to-disc ratio (P = 0.06), thinner RNFL (P = 0.02), and worse visual field mean deviation (MD, P = 0.06) than controls. The rate of RNFL thinning was faster in PPRS (average: −2.8%/year; range: −7.4% to 0.0%/year) than controls (−1.3%/year; range: −4.4% to 0.6%/year; P = 0.021). The rate of visual field MD change was faster in PPRS (−0.49 dB/year; range: −2.0 to 0.9 dB/year) than controls (−0.06 dB/year; range: −0.8 to 0.3 dB/year; P = 0.030). OCT scans showed hyperreflective structures spanning the PPRS whose morphology and spacing (50 ± 7 μm) are consistent with Müller glia, causing signal attenuation casting “shadows” onto distal retina.ConclusionsThis is the first report showing that glaucomatous PPRS is associated with a faster overall rate of RNFL thinning and visual field deterioration and to specifically identify OCT signs of Müller cell involvement.

Long‐term stability of an asymptomatic optic pit with foveolar retinoschisis

“…Other investigators have indicated the contrary, that the inner retinal schisis precedes the formation of the central serous detachment. However, cases where only an inner retinal schisis is present without a central serous detachment has also been documented . The variability of these presentations have been suggested to be contingent upon the presence of vitreo‐retinal traction, the volume of intravitreal fluid collection proximal to the optic pit and the outer retinal lamellar macular defects .…”

“…Another possible explanation to account for the long‐term stability may be related to the integrity of the Muller cells. For example, it has been documented that induced ablation of the Muller cells produce a spontaneous schisis at the inner retina . It has also been suggested that Muller cell anomalies may contribute to the pathogenies of X‐linked retinoschisis and analogous inter‐cellular adhesion defects in stellate nonhereditary idiopathic retinoschisis .…”

“…However, cases where only an inner retinal schisis is present without a central serous detachment has also been documented. [2][3][4][5][7][8][9][10][11][12][13][14][15][16][17][18][19] The variability of these presentations have been suggested to be contingent upon the presence of vitreoretinal traction, the volume of intravitreal fluid collection proximal to the optic pit and the outer retinal lamellar macular defects. 4,6,7,20 Another possibility is that the port of entry from the optic pit into the retina may vary spatially along the optic nerve and influence the type of presentation.…”

“…For example, it has been documented that induced ablation of the Muller cells produce a spontaneous schisis at the inner retina. 13,14 It has also been suggested that Muller cell anomalies may contribute to the pathogenies of X-linked retinoschisis and analogous inter-cellular adhesion defects in stellate nonhereditary idiopathic retinoschisis. 14,[22][23][24] Of relevance is the observation of the reactive gliosis of the Muller cells described in glaucoma.…”

“…Peripapillary vitreo‐retinal traction also contributes to the development of optic pit foveolar retinoschisis. Other factors implicated in the development of optic pit foveolar retinoschisis are retinal inter‐cell adhesion deficiencies and structural defects . Although a long‐term positive prognosis has been suggested, observation of the long‐term stability of optic pit foveolar retinoschisis has not been reported.…”