Correlation analysis between macular thickness and visual field mean defect in pseudoexfoliation glaucoma

Objective

To compare and analyze differences in macular thickness and to discuss the correlation between macular thickness and visual field mean defect (MD) in early and moderate, late pseudoexfoliation glaucoma (PXG) patients and normal control subjects.

Methods

A series of cases-observation study was adopted.Thirty-three early and moderate PXG patients (33 eyes) and 24 late PXG patients (24 eyes) were collected in the First Hospital of Shijiazhuang from May 2013 to May 2018.Meanwhile, 34 age, gender and dioper-matched healthy subjects (34 eyes) were included as normal control group.Spectral domain optical coherence tomography (SD-OCT) was used to measure macular thickness and volume in every quadrant.The correlation between the macular thickness and visual field MD were analyzed.This study followed the Helsinki declaration and was approved by the ethics committee of the First Hospital of Shijiazhuang.Written informed consent was obtained from each subject prior to any medical examination.

Results

The average macular thickness in normal control group, early and moderate PXG group and late PXG group were (305±15), (297±15) and (287±17)μm, respectively; the average macular volume were (0.94±0.05), (0.91±0.05) and (0.89±0.05)μm³, respectively.The macular thickness and volume differences between the 3 groups were statistically significant in nasal inner macula, superior inner macula, temporal inner macula, inferior inner macula, superior outer macula, temporal outer macula, inferior outer macula quadrants (F_thickness=4.226, 9.335, 12.133, 10.115, 11.298, 8.243, 12.142; all at P<0.05.F_volume=3.812, 9.152, 12.774, 8.889, 11.284, 7.937, 11.652; all at P<0.05). The macular thickness of early and moderate PXG group in superior inner macula, temporal inner macula, inferior inner macula, superior outer macula and temporal outer macula quadrants were statistically thinner than those in the normal control group (all at P<0.05); the macular thickness of late PXG group in inferior inner macula, temporal inner macula, superior outer macula and inferior outer macula quadrants were statistically thinner than those in the early and moderate PXG group (all at P<0.05); the macular thickness of late PXG group in inner and outer rings were statistically thinner than those in the normal control group (all at P<0.05). The macular thickness was not correlated with visual field MD in normal control group and the early and moderate PXG group in every quadrants (all at P>0.05), but it was positively correlated with visual field MD in the late PXG group in nasal inner macula, superior outer macula and temporal inner macula quadrants (r=0.527, 0.544, 0.417; all at P<0.05).

Conclusions

SD-OCT can quantify the macular thickness, and can be used an important reference index for the staging and follow-up of PXG combined with perimetry.

Optical coherence tomography; Pseudoexfoliation glaucoma; Macular thickness; Visual field mean defect; Correlation