Changes in peripapillary retinal nerve fiber layer thickness in patients with primary open-angle glaucoma after deep sclerectomy

Table 1 Demographic and clinical features of the studied patients

Parameters	Surgery group	Control group	P value1
No. of patients	35
Age (yr)	62.2 ± 2.5
Gender
Male	18 (51%)
Female	17 (49%)
Diabetes mellitus	8
Hypertension	25
Cup/Disc ratio	0.76 ± 2.4	0.57 ± 2.1	F = 3.52
			P = 0.0121
IOP diurnal range2	12.17 ± 2.21	8.26 ± 3.31	F = 4.64
			P = 0.0151
Preoperative IOP (mmHg)	23.4 ± 6.1	18.5 ± 2.3	F = 3.54
			P = 0.0151
Preoperative medication	3.1 ± 0.5	1.7 ± 0.4	F = 2.56
			P = 0.0211
Preoperative VF MD (dB)	-9.2 ± 5.3	-4.5 ± 4.1	F = 4.21
			P = 0.0171
Preoperative VF PSD (dB)	5.7 ± 3.1	4.8 ± 2.9	F = 4.56
			P = 0.25
Preoperative VA (logMAR)	0.73 ± 0.4	0.86 ± 0.2	F = 3.61
			P = 0.36

¹Significant at P < 0.05;

²Difference between the lowest and highest recorded intraocular pressure (IOP). One-way ANOVA test (F) and χ² test were used. VF: Visual field; MD: Mean deviation; VA: Visual acuity; PSD: Pattern standard deviation; logMAR: Logarithm of minimal angle of resolution.

Table 2 Mean peripapillary retinal nerve fiber layer thickness measurements in eyes that underwent deep sclerectomy compared with the contralateral eye of the same patient as measured by optical coherence tomography

Parameter	Pre-operative (μm)	Post-operative (μm)	P value1
Overall
Surgery group	71.6 ± 18.6	89.5 ± 21.2	0.0151
Control group	72.5 ± 17.8	71.7 ± 20.3	0.165
Superior quadrant
Surgery group	85.8 ± 25.1	96.7 ± 23.2	0.0211
Control group	85.7 ± 24.1	86.5 ± 21.5	0.114
Nasal quadrant
Surgery group	54.6 ± 21.5	72.0 ± 25.1	0.0141
Control group	56.5 ± 18.9	58.2 ± 22.1	0.356
Inferior quadrant
Surgery group	81.3 ± 25.1	69.2 ± 22.5	0.0231
Control group	83.1 ± 18.2	83.3 ± 20.1	0.453
Temporal quadrant
Surgery group	56.2 ± 19.2	75.2 ± 20.1	0.0161
Control group	57.0 ± 18.5	58.1 ± 21.5	0.451

¹Significant at P < 0.05.

Table 3 Pearson's correlation between change in mean retinal nerve fiber layer thickness and age, intraocular pressure, and global visual field indices in the surgery group

	r	P value1
Age	-0.164	0.276
IOP change (mmHg)	-0.235	0.023
IOP change (%)	-0.453	0.036
BCVA	-0.153	0.216
Preoperative VF MD (dB)	0.374	0.075
Preoperative VF PSD (dB)	-0.182	0.383
Change in VF MD	0.395	0.064
Change in VF PSD	0.186	0.625

¹Significant at P < 0.05. IOP: Intraocular pressure; BCVA: Best corrected visual acuity; VF: Visual field; MD: Mean deviation; PSD: Pattern standard deviation.