Morphological and Functional Inner and Outer Retinal Layer Abnormalities in Eyes with Permanent Temporal Hemianopia from Chiasmal Compression

Abstract

PurposeThe aims of this study are to compare optical coherence tomography (OCT)-measured macular retinal layers in eyes with permanent temporal hemianopia from chiasmal compression and control eyes; to compare regular and slow-flash multifocal electroretinography (mfERG) in patients and controls; and to assess the correlation between OCT, mfERG, and central visual field (SAP) data.MethodsForty-three eyes of 30 patients with permanent temporal hemianopia due to pituitary tumors who were previously submitted to chiasm decompression and 37 healthy eyes of 19 controls were submitted to macular spectral domain OCT, mfERG, and 10-2 SAP testing. After segmentation, the thickness of the macular retinal nerve fiber layer (RNFL), ganglion cell layer (GCL), inner plexiform layer (IPL), inner nuclear layer (INL), outer plexiform layer (OPL), outer nuclear layer, and photoreceptor layer (PRL) was measured. Amplitudes and oscillatory potentials (OPs) were measured on regular and slow-flash mfERG, respectively, and expressed as the mean values per quadrant and hemifield.ResultsRNFL, GCL, and IPL thickness measurements were significantly reduced in all quadrants, whereas INL, OPL, and PRL thicknesses were significantly increased in the nasal quadrants in patients compared to those in controls. Significant correlations between OCT and 10-2 SAP measurements were positive for the RNFL, GCL, and IPL and negative for the INL, OPL, and PRL. OPs and mfERG N1 amplitudes were significantly reduced in the nasal hemiretina of patients. Significant correlations were found between OP and mfERG amplitudes for inner and outer nasal hemiretina OCT measurements, respectively.ConclusionPatients with permanent temporal hemianopia from previously treated chiasmal compression demonstrated significant thinning of the RNFL, GCL, IPL, and thickening of the INL, OPL, and PRL associated with reduced OP and mfERG N1 amplitudes, suggesting that axonal injury to the inner retina leads to secondary damage to the outer retina in this condition.

Optical coherence tomography analysis of inner and outer retinal layers in eyes with chiasmal compression caused by suprasellar tumours

“…Another study involving 43 eyes with permanent hemianopsia also reported thinning of RNFL, GCL and IPL in all regions similar to our study (de Araujo et al. ). In our study, the thickness of RNFL, GCL, IPL and IRL decreased in patients with chiasmal compression compared with the control group at 1 year postoperatively, consistent with previous reports.…”

“…; de Araujo et al. ). These studies also revealed inner nuclear layer (INL) thickening (Monteiro et al.…”

“…; de Araujo et al. ). The INL thickening involves development of INL microcysts in the area of ganglional loss as retrograde trans‐synaptic degeneration (Vanburen ; Jindahra et al.…”

Identification of clusters in multifocal electrophysiology recordings to maximize discriminant capacity (patients vs. control subjects)

“…• With multifocal visual-evoked potentials, it can be used to analyse mfERG, mfVEP or mfPERG 8,9,10,13,17,20,25,28,34,37,42,45,49,52,53,54,55 0:5125 0:5328 0:5438…”

“…Another study [6] concludes that using the central ring in mfERGs is an appropriately sensitive technique with which to study the progression of age-related macular degeneration over short periods of time. Analysis by quadrant makes it possible to carry out comparisons between mfERG studies and optical coherence tomography (OCT) [7,8]. It is also common to find the results of clustering by ring and quadrant in publications that analyse the technical aspects of mfERG [9,10].…”