Neuroretinal rim in non-glaucomatous large optic nerve heads: a comparison of confocal scanning laser tomography and spectral domain optical coherence tomography.
To compare margin-based rim area measurements from confocal scanning laser tomography (CSLT) with Bruch's membrane opening (BMO)-based measurements from spectral domain optical coherence tomography (SD-OCT) by analysis of a group of non-glaucomatous eyes with large optic discs, so-called macrodiscs (disc size >2.45 mm2in CSLT). Objective is to create a reference base for large optic nerve heads in SD-OCT diagnostics.



102 eyes received CSLT and SD-OCT measurements and clinical examination on the same day. Visual field testing confirmed absence of glaucomatous defects. Statistical and correlation analysis was performed for rim area by CSLT as well as retinal nerve fibre layer thickness (RNFLT) and BMO minimal rim width (BMO-MRW) by SD-OCT.



Mean disc size in CSLT was 2.98±0.4 mm2(range 2.45-4.23), mean rim area of 1.55±0.4 mm2. BMO area was 2.51±0.33 mm2(range 1.61-3.51), mean global RNFLT was 79.55±17.2 μm, mean global BMO-MRW was 234.84±48.3 μm. Correlation of BMO-MRW to global RNFLT was stronger (r=0.60, p<10-5) than correlation of CSLT rim area to global RNFLT (r=0.26, p=0.24). BMO-MRW and CSLT rim area correlated with r=0.59 (p<10-5). BMO-MRW and RNFLT significantly decreased with increasing age (p<0.001). Annual loss of BMO-MRW was 0.8 μm/year (R2=0.14, p<0.001), loss of RNFLT was 0.27 μm/year (R2=0.17, p=0.001).



In large optic discs, BMO-MRW is thinner compared with normal-sized discs and correlates better than CSLT parameters with the RNFLT. An age-depended loss of BMO-MRW needs to be taken into account in evaluation of the neuroretinal rim.
Department of Ophthalmology, University Hospital of Cologne, Cologne, Germany.
Philip
P
Enders
Department of Ophthalmology, University Hospital of Cologne, Cologne, Germany.
Friederike
F
Schaub
Department of Ophthalmology, University Hospital of Cologne, Cologne, Germany.
Manuel M
MM
Hermann
Department of Ophthalmology, University Hospital of Cologne, Cologne, Germany.
Claus
C
Cursiefen
Department of Ophthalmology, University Hospital of Cologne, Cologne, Germany.
Ludwig M
LM
Heindl
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016570:Bruch Membrane / Q000473:pathology; D002648:Child; D002675:Child, Preschool; D005260:Female; D005901:Glaucoma / Q000175:diagnosis*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009412:Nerve Fibers / Q000473:pathology; D009898:Optic Disk / Q000002:abnormalities*; D012160:Retina / Q000473:pathology*; D012165:Retinal Ganglion Cells / Q000473:pathology; D012189:Retrospective Studies; D041623:Tomography, Optical Coherence / Q000379:methods; D055815:Young Adult
Glaucoma; Imaging; Optic Nerve