Compressive chiasmal lesions: optical coherence tomography, ganglion cell and inner plexiform layers and visual field tests

Abstract

AbstractPurpose The authors present an analysis of the automated macular ganglion cell complex measurements in patients with compressive chasmal lesions.Methods Observational study of 20 eyes of 20 patients with compressive chiasmal lesions followed at the neurophthalmology outpatient clinic. Optical Coherence Tomography (OCT SPECTRALIS® ‐ Heidelberg Engineering GmbH) was performed and high‐resolution macular scans were obtained. Ganglion cell layer and inner plexiform layer (GCL+IPL) average thickness and retinal nerve fiber layer (RNFL) thickness were also determined. A functional evaluation was performed with Static Computerized Perimetry (Octopus Perimetry®, Haag‐Streit). Statistical analysis was done with SPSS Statistics. A p value < 0.05 was considered statistically significant.Results There was a significant decrease in the RNFL and GCL+IPL thickness when compared with average values from normal population (p<0,05). Average RNFL and GCL+IPL thickness reduction evaluated by OCT were positively correlated. We identified a positive structural and functional correlation between the tomographic and perimetric evaluations. Nevertheless, 4 of the 20 patients had normal visual fields.Conclusion Although the changes determined by OCT and perimetry are different, both methods are useful in studying the relationship between structure and function in patients with chiasmal compressive lesions. Structural damage documented by OCT was associated in the majority of the patients with functional damage. This study also emphasizes the importance of the GCL+IPL thickness measurement with OCT. Evaluation of RNFL and GCL+IPL with OCT appears to be accurate in predicting functional damage.