Article Text
Abstract
Background/Aims To determine the effect of glaucoma on outer retinal layer thickness in eyes with horizontal hemifield visual field (VF) defects.
Methods We conducted a cross-sectional study in glaucomatous eyes with repeatable (in three or examinations) horizontal hemifield VF (programme 24–2) defect defined as: all five nasal VF locations immediately either above or below the horizontal midline abnormal in the pattern deviation plot with p<0.5%; no mirror-image adjacent 5 VF locations abnormal in the pattern deviation plot and no non-edge VF locations in the non-affected hemifield abnormal in the pattern deviation plot with p<1%. We used optical coherence tomography to measure thickness of each retinal layer in the temporal macula (12° horizontally and 24° vertically) and computed the absolute (µm) and relative (%) intraindividual asymmetry between the perimetrically normal and abnormal hemimacula.
Results We included 10 eyes of 8 patients with median age of 67 years and median VF mean deviation of −8.85 dB. The nerve fibre, ganglion cell and inner plexiform layers were significantly thinner in the perimetrically abnormal hemimacula (median asymmetry of –6.4, –11.5 and −3.8 µm, (corresponding to –27.7, –40.5 and −15.7 %), respectively, all p≤0.01). The inner nuclear layer was slightly thicker in the perimetrically abnormal hemimacula (median asymmetry of 1.3 µm (5.0 %), p=0.01). The outer plexiform, outer nuclear and photoreceptor layers asymmetry values were negligible.
Conclusion Our study showed no evidence that glaucoma has an effect on the outer retinal layer thickness. In contrast, a large impact was observed in inner layer thickness.
- glaucoma
- retina
- imaging
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Footnotes
Contributors Conception and design: JRV, ZB, MTN, BCC. Data acquisition: ZB, GPS, DMH. Analysis and interpretation: all authors. Drafting and revising the manuscript: all authors.
Funding This work was supported by Canadian Institutes for Health Research, grant number MOP 11357 and by Heidelberg Engineering with equipment and research support.
Disclaimer All authors fulfil ICMJE authorship criteria.
Competing interests JRV, ZB, LAT, GPS, DMH: none declared. MTN: Consultant and Lecturer—Allergan, Alcon. LMS: Financial support—Allergan; Lecturer—Allergan, Alcon. BCC: Consultant—Allergan, Heidelberg Engineering; Lecturer—Allergan; Equipment support—Heidelberg Engineering, Topcon.
Patient consent Not required.
Ethics approval Nova Scotia Health Authority Research Ethics Board.
Provenance and peer review Not commissioned; externally peer reviewed.