Optic neuritis (ON) causes axonal loss as reflected by thinning of retinal nerve fiber layer (RNFL) and can be tracked by optical coherence tomography (OCT) about 6 months after ON onset, when swelling of optic nerve head (ONH) has vanished. Changes of macular ganglion cell layer (GCL) thickness provide another window to track the disease process in ON. GCL thinning over time in relation to RNFL change after ON remains elusive. Using OCT, we followed 4 patients with acute unilateral isolated ON for more than 9 months. A diagnosis of multiple sclerosis (MS) was established in all 4 patients. First follow-up was 2-3 weeks after ON onset, and thereafter every 2-3 months. RNFL swelling peaked during first month after acute ON, followed by rapidly reduced swelling (pseudoatrophy) during following 2 months, and thereafter successively vanished 6 months after ON onset. GCL thinning was observed 1-3 months after ON onset, i.e. already during optic disk swelling and before real RNFL thinning. The results imply that quantifying GCL thickness provides opportunities to monitor early axonal loss and ON-to-MS progression, and facilitates distinguishing real atrophy from pseudoatrophy of RNFL after acute ON.

Objective: Severity of papilledema and vision loss constitute a basis for therapeutic intervention in idiopathic intracranial hypertension (IIH), but both are often subjective and insensitive in guiding clinical management. The aim of this study was to identify reliable and sensitive measurements of optic nerve head (ONH) and macula, to provide objective guidance for prognostic evaluation and treatment in IIH. We analyzed potential of spectral domain optical coherence tomography (SD-OCT), to measure neuro-retinal rim thickness and area, optic cup-to-disc ratio (C/D) and cup volume of ONH which have not previously been reported in IIH. In parallel, thickness of peripapillary retinal nerve fiber layer (RNFL) and macular ganglion cell layer (GCL) together with inner plexiform layer (IPL) (GCL-IPL) were examined. Results: All 7 enrolled IIH patients had increased neuro-retinal rim thickness (p less than 0.01 for both eyes) and rim area (p less than 0.05), decreased C/D (p less than 0.01) and optic cup volume (p less than 0.01) when compared to findings in 18 sex- and age-matched healthy controls (HC). In a longitudinal study, two IIH patients were followed repetitively by SD-OCT before and after measurement of intracranial pressure (ICP) and removal of cerebrospinal fluid (CSF) by lumbar puncture. Rim thickness and area, C/D and optic cup volume remained altered. RNFL thickness may change with very high ICP, but not immediately after CSF removal. GCL-IPL thickness was unchanged irrespective of ICP change or CSF removal. Conclusion: SD-OCT allows detection of ONH changes even in subtle IIH without papilledema and has potential for routine use in IIH.

Background The ganglion cell layer (GCL) measurements with Optical Coherence Tomography (OCT) are important for both ophthalmologists and neurologists because of their association with many ophthalmic and neurological diseases. Different factors can affect these measurements, such as brain pathologies, ocular axial length (AL) as well as age and sex. Studies conducted to measure the GCL have overlooked many of these factors. The purpose of this study is to examine the effect of age, sex, and AL on normal retinal GCL thickness and volume in a healthy population without any neurological diseases. Methods A prospective cross-sectional study was designed to measure GCL thickness and total volume with OCT with automated segmentation and manual correction where needed. Visual acuity, AL, and autorefraction were also measured. A mixed linear model was used to determine the association of the effect of the various parameters on the GCL thickness and volume. Results One hundred and sixteen eyes of 60 subjects (12-76 years of age, 55% female) were examined of which 77% had 0 +/- 2 D of spherical equivalent, and mean axial length was 23.86 mm. About 25% of the OCT-automated GCL measurements required manual correction. GCL thickness did not differ in similar anatomic regions in right and left eyes (P > 0.05). GCL volume was greater in males relative to females after adjustment for age and axial length (1.13 +/- 0.07 mm(3) for males vs 1.09 +/- 0.09 mm(3) for females; P = 0.031). GCL thickness differed between males and females in the inner retinal ring (P = 0.025) but not in the outer ring (P = 0.66). GCL volume declined with age (P = 0.031) but not after adjustment for sex and axial length (P = 0.138). GCL volume declined with longer axial length after adjustment for age and sex (P = 0.048). Conclusion Age, sex and axial length should be taken into consideration when measuring the GCL thickness and volume with OCT. Automated OCT segmentation should be reviewed for manual adjustments.

A benign form of multiple sclerosis (BMS) is not easily diagnosed, but changes of the retinal ganglion cell layer-inner plexiform layer (GCL-IPL) and retinal nerve fiber layer (RNFL) may be sensitive to the disease. The aim of this study was to use optical coherence tomography (OCT) to investigate longitudinal changes of GCL-IPL and RNFL in BMS. Eighteen patients with BMS and 22 healthy control (HC) subjects were included, with a mean follow-up period of 32.1 months in BMS and 34.3 months in HC. Mean disease duration in BMS was 23.3 years, with 14 patients left untreated. Unilateral optic neuritis (ON) was found in eight patients. Non-ON eyes showed thinner GCL-IPL layer in the BMS group relative to HC (p < 0.001). The thinning rate of GCL-IPL in non-ON BMS, however, was -0.19 +/- 0.15 mu m/year vs. 0 +/- 0.11 mu m/year for HC (p = 0.573, age-adjusted). Thinning rate of RNFL in non-ON BMS was -0.2 +/- 0.27 mu m/year vs. -0.05 +/- 0.3 mu m/year for HC (p = 0.454, age adjusted). Conclusions: Thinning rate of the GCL-IPL and RNFL in BMS is similar to the healthy population but differs from the thinning rate in relapsing-remitting MS, presenting a non-invasive OCT-based criterion for assessing a benign course in multiple sclerosis.