Optic Nerve Head Morphology in Nonarteritic Anterior Ischemic Optic Neuropathy Compared to Open-Angle Glaucoma.
OBJECTIVE
To compare optic nerve head (ONH) morphology of optic nerve atrophy between eyes with primary open-angle glaucoma (POAG) and eyes with a history of nonarteritic anterior ischemic optic atrophy (NAION) using enhanced depth imaging (EDI) with spectral-domain optical coherence tomography (SD-OCT).


METHODS
In this cross-sectional study, 121 eyes of 91 patients consisted of moderate to severe POAG (n = 32 eyes), visual field mean deviation-matched NAION (n = 30 eyes) and their fellow eyes (n = 30 eyes), and healthy controls (n = 29). The optic discs were scanned using SD-OCT and measurements were obtained using HEYEX software 6.0. Lamina cribrosa (LC) thickness and anterior lamina cribrosa depth (ALD) at three scans (midsuperior, central, and midinferior) were determined and compared. In addition, prelaminar tissue thickness was measured at three points of a single central scan.


RESULTS
There was no significant difference in the visual field mean deviation (MD) between the NAION and POAG groups (P > 0.99), but both groups had a significantly worse MD than the healthy group (P < 0.001). The NAION and POAG groups had similar peripapillary retinal nerve fiber layer (pRNFL) thickness (P < 0.99). Eyes with POAG had greater ALD and thinner LC than control eyes and NAION eyes in all regions of the ONH (P < 0.001 for both). There was a marked prelaminar tissue thinning in POAG eyes compared to control and NAION eyes (P < 0.001). Lamina cribrosa thickness and ALD of NAION eyes were not different from their fellow eyes and control eyes. Although prelaminar thickness was thinner in NAION eyes compared to their fellow eyes (P = 0.005), it was thicker than in control eyes (P < 0.001).


CONCLUSIONS
Despite profound thinning and posterior displacement of LC in POAG, the thickness and position of LC in NAION eyes are similar to those seen in healthy control and their fellow eyes.
Eye Research Center, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran.
Masoud Aghsaei
MA
Fard
Eye Research Center, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran.
Marjan
M
Afzali
Eye Research Center, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran.
Parisa
P
Abdi
Case Western Reserve University School of Medicine, Cleveland, Ohio, United States 3Department of Ophthalmology, University of California-San Francisco, San Francisco, California, United States.
Rebecca
R
Chen
Eye Research Center, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran 4Department of Epidemiology and Biostatistics, Tehran University of Medical Sciences, Tehran, Iran.
Mehdi
M
Yaseri
Eye Research Center, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran.
Ebrahim
E
Azaripour
Eye Research Center, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran 3Department of Ophthalmology, University of California-San Francisco, San Francisco, California, United States.
Sasan
S
Moghimi
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003430:Cross-Sectional Studies; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D005902:Glaucoma, Open-Angle / Q000175:diagnosis* / Q000503:physiopathology; D006801:Humans; D007089:Image Enhancement; D007429:Intraocular Pressure; D008297:Male; D008875:Middle Aged; D009898:Optic Disk / Q000473:pathology*; D018917:Optic Neuropathy, Ischemic / Q000175:diagnosis* / Q000503:physiopathology; D012165:Retinal Ganglion Cells / Q000473:pathology; D012189:Retrospective Studies; D012720:Severity of Illness Index; D041623:Tomography, Optical Coherence / Q000379:methods*; D014794:Visual Fields