Effects of vitrectomy combined with internal limiting membrane peeling in patients with diabetic macular edema

Table 1 Baseline demographic and clinical data of the study participants (n = 81, 92 eyes)

Group (number of cases/eyes affected)	Gender (n)		Age, mean ± SD (yr)	Diabetes classification (n)		Intraocular pressure, mean ± SD (mmHg)	Duration of diabetes, mean ± SD (yr)
	Male	Female		Type I	Type II
Control group (41/47)	21	20	51.46 ± 8.41	8	33	15.16 ± 2.77	10.06 ± 2.91
Stripping group (40/45)	17	23	53.73 ± 9.56	11	29	15.23 ± 3.83	10.03 ± 3.22
t/χ2	0.618		1.135	0.720		0.094	0.044
P value	0.432		0.260	0.396		0.925	0.965

Table 2 Comparison of central macular thickness between the two study groups (n = 92 eyes)

Group (number of affected eyes)	CMT (μm) (mean ± SD)			F	P value
	Preoperative	1 month after surgery	3 months after surgery
Control group (n = 47)	383.83 ± 84.31	334.37 ± 95.46	270.95 ± 76.24	Fgroup = 8.854	Pintergroup = 0.004
Stripping group (n = 45)	372.75 ± 104.76	262.35 ± 83.85	214.48 ± 69.69	Ftime = 500.634	Ptime < 0.001
t	0.560	3.838	3.703	Finteraction = 7.403	Pinteraction = 0.001
P value	0.577	< 0.001	< 0.001

CMT: Central macular thickness.

Table 3 Comparison of best-corrected visual acuity levels between the two study groups (n = 92 eyes)

Group (number of affected eyes)	BCVA (logMAR) (mean ± SD)			F	P value
	Before surgery	1 month after surgery	3 months after surgery
Control group (n = 47)	1.84 ± 0.64	1.39 ± 0.54	1.04 ± 0.39	Fgroup = 7.978	Pintergroup = 0.006
Stripping group (n = 45)	1.67 ± 0.46	1.03 ± 0.32	0.79 ± 0.30	Ftime = 441.237	Ptime < 0.001
t	1.457	3.868	0.436	Finteraction = 17.105	Pinteraction < 0.001
P value	0.149	< 0.001	< 0.001

BCVA: Best-corrected visual acuity.

Table 4 Comparison of the volume of cystoid macular edema between the two groups (n = 92 eyes)

Group (number of affected eyes)	Macular edema cyst volume (mm3) (mean ± SD)			F	P value
	1 week after surgery	1 month after surgery	3 months after surgery
Control group (n = 47)	12.77 ± 1.58	12.06 ± 1.28	11.19 ± 1.30	Fgroup = 9.374	Pintergroup = 0.003
Stripping group (n = 45)	12.89 ± 1.27	10.99 ± 1.34	9.57 ± 1.34	Ftime = 1838.956	Ptime < 0.001
t	0.400	3.917	5.886	Finteraction = 210.654	Pinteraction < 0.001
P value	0.690	< 0.001	< 0.001