Microperimetry and optical coherence tomography imaging in the fellow eye of patients with unilateral focal ischaemic glaucoma

Purpose To determine whether microperimetry or optical coherence tomography (OCT) imaging can detect early disease in the fellow eye of patients with unilateral focal ischaemic glaucoma. Methods Thirty-seven consecutive adult patients with unilateral focal ischaemic glaucoma with a unilateral split-fixation visual field defect on standard automated perimetry (SAP) with normal SAP in the fellow eye were selected. All patients underwent microperimetry (MAIA, CenterVue, Italy) of the central 10 degrees and OCT imaging (Spectralis, Heidelberg Engineering, Germany) of the retinal nerve fibre layer of both eyes. The main outcome measures were reduced retinal sensitivity on microperimetry and/or retinal nerve fibre layer thinning on OCT imaging of the fellow eye. Results Thirty fellow eyes had abnormal global thresholds on microperimetry, and 20 had abnormal OCT imaging studies. Kappa agreement between tests in fellow eyes was poor (p = 0.2546). Fixation was significantly poorer in fellow eyes on microperimetry when compared to eyes with glaucoma (p < 0.003). In the fellow eyes that were abnormal, microperimetry identified reduced retinal sensitivity at fixation. Conclusion Microperimetry detects reduced retinal sensitivity close to fixation and OCT detects focal thinning of the retinal nerve fibre layer in the fellow eye of most patients with presumed unilateral focal ischaemic glaucoma. Further studies are required to correlate specific optic disc features on OCT imaging with microperimetry in the fellow eye of this patient group