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PurposeTo evaluate the ability of frequency domain optical coherence tomography (fd-OCT) to estimate retinal neural loss in eyes with Alzheimer’s disease (AD). We also verified the existence of a correlation between AD-related cognitive impairment and macular and peripapillary retinal nerve fiber layer (RNFL) thickness measurements.Methodsfd-OCT scans were obtained from 45 eyes of 24 patients with AD and 48 control eyes. Peripapillary RNFL, macular full-thickness and segmented inner macular thickness parameters were calculated. The inner macular parameters included macular retinal nerve fiber layer (mRNFL) thickness, ganglion cell layer (GCL) plus inner plexiform layer thickness (GCL+), and RNFL plus GCL+ thickness (GCL++). The Mini-Mental State Examination (MMSE) was used to assess cognition in all subjects. The two groups were compared and the relationship between MMSE scores and fd-OCT measurements was verified.ResultsAverage, superior and inferior quadrant RNFL thickness parameters and all but one of the nine full-thickness macular measurements were significantly reduced in AD patients compared to controls. The segmented layers, GCL+ and GCL++ were significantly reduced in AD eyes. A significant correlation was found between most fd-OCT parameters (especially macular thickness measurements) and MMSE scores.ConclusionsMost fd-OCT peripapillary RNFL and macular full-thickness and segmented inner retinal layers parameters were reduced in AD eyes compared to controls. Moreover, neuronal loss, especially as reflected in macular parameters, correlated well with cognitive impairment in AD. Our results suggest that fd-OCT could be a potentially useful diagnostic tool in the evaluation and follow-up of AD patients.

Although FD-OCT RNFL and macular thickness measurements can reveal subclinical or optic neuritis-related abnormalities in NMO-spectrum and MS patients, abnormalities are predominant in the macula of MS patients and in RFNL measurements in NMO patients. The correlation between OCT and VF abnormalities was stronger in NMO than in MS, suggesting the two conditions differ regarding structural and functional damage. (ClinicalTrials.gov number, NCT01024985.).

Purpose To evaluate the thickness of the inner retinal layers in the macula using frequency domain-optical coherence tomography (fd-OCT) in patients with demyelinating diseases. Design Cross sectional study Participants 301 eyes of 176 subjects were evaluated. Subjects were divided in 5 different groups: controls, neuromyelitis optica (NMO), longitudinally extensive transverse myelitis (LETM), multiple sclerosis with (MS-ON) and without (MS non-ON) history of optic neuritis, respectively. Methods The individual layers from macular fd-OCT cube scans were segmented with an automated algorithm, and then manually hand-corrected. For each scan, we determined the thickness of the retinal nerve fiber layer (RNFL), the combined retinal ganglion cell and inner plexiform layers (RGCL+), and the inner nuclear layer (INL). Main outcome measures Macular RNFL, RGCL+ and INL thickness Results The RNFL was significantly thinner than controls for all patient groups (p≤0.01). Macular RGCL+ thickness was significantly thinner than controls for the NMO, MS-ON and MS non-ON (p<0.001 for the 3 groups). The INL thickness was significantly thicker than controls for the NMO (p=0.003) and LETM (p=0.006) patients but not for MS-ON or MS non-ON. While the RNFL and RGCL+ were not significantly different between the NMO and MS-ON groups, the NMO patients had a significantly thicker INL than the MS-ON (p=0.02) patients. Conclusion Macular RNFL and RGCL+ demonstrate axonal and neural loss in MS, either with or without ON, and in NMO patients. In addition, the INL thickening occurs in NMO and LETM patients and study of this layer may hold promise for differentiating between NMO and MS.

Band atrophy leads to mRNFL and RGCL+ thinning, and INL thickening, and mRNFL and RGCL+ measurements are correlated strongly with VF loss. Segmented macular thickness measurements may be useful for quantifying neuronal loss in chiasmal compression.

Exposure to air pollution reduces tear film stability and influences tear film osmolarity. Combining clinical examination with the assessment of tear osmolarity may help understand ocular surface response to high levels of air pollution.

Aims: To measure axonal loss in patients with band atrophy of the optic nerve caused by optic chiasm compression using optical coherence tomography and to evaluate its ability in identifying this pattern of retinal nerve fibre layer (RNFL) loss. Methods: Twenty eyes from 16 consecutive patients with band atrophy of the optic nerve and permanent temporal hemianopia due to chiasmal compression, and 20 eyes from an age and sex matched control group of 16 healthy individuals, were studied prospectively. All patients were submitted to an ophthalmic examination including perimetry and evaluation of the RNFL using optical coherence tomography. Mean RNFL thickness around the optic disc was compared between the two groups. ivisions provided by the equipment also showed significantly different values between eyes with band atrophy and normal controls. Conclusions: Optical coherence tomography was able to identify axonal loss in all four quadrants as well as in each of the twelve 30˚segments of the disc. Thus, it seems to be a promising instrument in the diagnosis and follow up of neuroophthalmic conditions responsible for RNFL loss, even if predominantly in the nasal and temporal areas of the optic disc.