Risk factors for requirement of filtration surgery after vitrectomy in patients with proliferative diabetic retinopathy

Figures & data

Table 1 Patient demographic characteristics

	Filtration surgery (+)	Filtration surgery (−)	P-value
n	40	21	–
Male sex, %	85	71.4	0.31
Age, years	51.9±10.3	53.3±6.2	0.69
PRP (+), %	62.5	76.2	0.39
Presence of lens before vitrectomy, %	85	95.2	0.40
Rubeosis, %	10	14.3	0.68
TRD (+), %	42.5	23.8	0.17
ME (+), %	15	23.8	0.49
VH (+), %	52.5	66.7	0.41
Use of gas tamponade, %	70	23.8	<0.01
Preoperative logMAR	1.21±0.67	1.36±0.60	0.37
Preoperative IOP, mmHg	14.8±3.4	15.4±3.3	0.39
LogMAR after vitrectomy	1.43±0.8	0.90±0.8	0.02
IOP after vitrectomy, mmHg	37.3±11.6	30.7±7.8	0.03
HbA1c, %	7.1±1.4	7.4±1.7	0.56
FBG, mg/dL	148.0±39.6	195.9±72.0	<0.01
eGFR, mL/min/1.73 m^2	69.4±26.1	82.3±29.2	0.12
Mean time to NVG onset, months	5.1±3.9	11±7.6	<0.01
Preoperative IVB, %	10	15	0.54
IVB immediately after surgery, %	10	3	0.23
Incision size of PPV (25G vs 20G), %	67	73	0.64

Notes: Data are expressed as mean ± SD. The proportion of male patients was analyzed by Fisher’s exact test. Between-group comparisons for a history of PRP, presence/absence of lens before surgery, obvious iris/angle neovascularization, TRD, diabetic macular edema, vitreous hemorrhage, and use of gas tamponade were analyzed by Fisher’s exact test. The values for age, IOP, and visual acuity before vitreous surgery and at NVG onset, HbA_1c, FBG, eGFR, and time to onset of postoperative NVG were analyzed by the Mann–Whitney U test. Between-group comparisons of preoperative IVB, IVB after surgery, and PPV incision size were analyzed by the chi-squared test.

Abbreviations: eGFR, estimated glomerular filtration rate; FBG, fasting blood glucose; HbA_1c, glycated hemoglobin; IOP, intraocular pressure; IVB, intravitreal bevacizumab; ME, macular edema; NVG, neovascular glaucoma; PPV, pars plana vitrectomy; PRP, panretinal photocoagulation; TRD, tractional retinal detachment; VH, vitreous hemorrhage.

Table 2 Logistic regression analysis of the risk factors for requirement of filtration surgery in patients with postoperative neovascular glaucoma after proliferative diabetic retinopathy surgery

	OR (95% CI)	P-value
Male, %	1.68 (0.15–18.60)	0.67
Age, years	0.94 (0.83–1.05)	0.28
PRP (+), %	0.71 (0.06–8.75)	0.79
Presence of lens before vitrectomy, %	0.54 (0.02–15.82)	0.72
Rubeosis, %	1.61 (0.10–25.06)	0.73
TRD (+), %	0.22 (0.01–4.16)	0.31
ME (+), %	0.49 (0.01–17.51)	0.70
VH (+), %	0.23 (0.01–4.75)	0.34
Use of gas tamponade, %	25.5 (0.98–668.84)	0.05
Preoperative logMAR	0.62 (0.09–4.10)	0.62
Preoperative IOP, mmHg	1.05 (0.72–1.52)	0.80
LogMAR after vitrectomy	0.95 (0.24–3.72)	0.94
IOP after vitrectomy, mmHg	1.11 (0.96–1.27)	0.15
HbA1c, %	0.45 (0.16–1.33)	0.15
FBG, mg/dL	1.03 (1.00–1.05)	0.03
eGFR, mL/min/1.73 m^2	0.98 (0.94–1.07)	0.24

Abbreviations: eGFR, estimated glomerular filtration rate; FBG, fasting blood glucose; HbA_1c, glycated hemoglobin; IOP, intraocular pressure; ME, macular edema; OR, odds ratio; PRP, panretinal photocoagulation; TRD, tractional retinal detachment; VH, vitreous hemorrhage.

Table 3 Backward elimination method of logistic regression analysis of the risk factors for the requirement of filtration surgery in patients with postoperative neovascular glaucoma after surgery for proliferative diabetic retinopathy

	OR (95% CI)	P-value
Use of gas tamponade, %	8.22 (1.75–38.52)	0.008
IOP after vitrectomy, mmHg	1.09 (1.00–1.19)	0.04
HbA1c, %	0.50 (0.24–1.01)	0.05
FBG, mg/dL	1.03 (1.01–1.05)	0.008

Abbreviations: FBG, fasting blood glucose; HbA_1c, glycated hemoglobin; IOP, intraocular pressure; OR, odds ratio.