The correlation of ganglion cell layer thickness with visual field defect in non-functional pituitary adenoma with chiasm compression

Abstract

Objective: To investigate the consequences of the thickness of ganglion cell layer (GCL) and visual field defect of non-functional pituitary adenoma with chiasm compression. Methods: A case control study. The study included 40 (80 eyes) non-functional pituitary adenoma patients in Peking Union Medical College Hospital from March 2015 to February 2017. Twenty patients (no visual field defect group, 40 eyes) of them were detected to be chiasm compressed or touched by the adenoma with no visual field defect detected, and the other 20 patients (visual field defect group, 40 eyes) were the sex-and-age matched pituitary adenoma patients with bitemporal heminopsia. This study also included 20 (control group, 40 eyes) sex-and-age matched healthy controls. The para-papillary retinal nerve fiber layer (RNFL) thickness in 6 quadrants including nasal, temporal, nasal superior, temporal superior, nasal inferior and temporal inferior as well as the macular GCL thickness and ganglion cell-inner plexiform layer (GCIPL) thickness in 4 quadrants including nasal superior, nasal inferior, temporal superior and temporal inferior were measured. The non-parametric test was used to compare the RNFL, GCL and GCIPL thickness among the three groups. Results: The mean age among the three groups was (46±10) years and the difference among the three groups was not significant (P=0.88). The sex ratio of the three groups was 9∶11 (male∶female) and the difference among the three groups was not significant. The mean axial length among the three groups was (23.22±0.90) mm and the difference among the three groups was not significant (P=0.51). The thickness of para-papillary RNFL of temporal superior, temporal, nasal superior, nasal, nasal inferior quadrants and whole circumference was significantly thinner in the visual field defect group than the control group [(129.88±28.64) μm, (63.63±26.84) μm, (88.08±32.16) μm, (50.68±19.99) μm, (92.48±25.06) μm, and (85.00±20.65) μm vs. (141.10±18.95) μm, (79.12±16.78) μm, (113.68±21.28) μm, (69.67±14.23) μm, (117.80±31.32) μm, and (102.80±9.68) μm, t=2.26, 3.06, 4.14, 4.84, 4.25, 4.88, all P<0.05]. In the nasal quadrant, the para-papillary RNFL of the no visual field defect group was significantly thinner compared with the control group [(61.45±9.83) μm vs. (69.67±14.23) μm, t=2.97, P<0.05]. The total GCL thickness was (30.48±5.42) μm in the visual field defect group, (31.35±2.77) μm in the no visual field defect group, thinner than that in the control group [(33.32±2.92) μm, t=2.92, 3.62; both P<0.05]. The total GCIPL thickness showed no significant difference among the three groups (P=0.07). In the superior and inferior temporal quadrants, the GCL and GCIPL thickness showed no significant difference among the three groups (all P>0.05). In the superior and inferior nasal quadrants, the GCL thickness was (29.41±5.97) μm, and (28.47±5.13) μm in the visual field defect group, (31.15±3.27) μm and (30.61±2.96) μm in the no visual field defect group, and (34.23±3.16) μm and (32.97±2.78) μm in the control group. The GCL thickness in the nasal quadrant was thinner in the visual field defect group (t=4.45, 4.82)and the no visual field defect group(t=4.23, 3.63) than in the control group (all P<0.01). However, no significant difference in GCL thickness was detected between the visual field defect group and the no visual field defect group (both P>0.05). In the superior and inferior nasal quadrants, the GCIPL thickness was (54.06±10.50) μm and (51.77±9.18) μm in the visual field defect group, (58.03±4.00) μm and (56.23±5.37) μm in the no visual field defect group, and (62.26±7.11) μm and (59.39±6.64) μm in the control group. The GCIPL thickness was thinner in the nasal quadrant in the visual field defect group than in the control group (t=3.95, 4.20, both P<0.01). Only in the Superior nasal quadrant, the GCIPL was significantly thinner in the no visual field defect group than the control group (t=3.25, P<0.01). Conclusion: The optic GCL may get thinner in pituitary nonfunctional adenoma with chiasm compression patients without the RNFL layer thinning and visual field defect. (Chin J Ophthalmol, 2019, 55: 186-194).