The Clinical Study Of The More Complex Rhegmatogenous Retinal Detachment Cured By The Pars Plana Vitrectomy

Objective: To approach the clinical effects of primary pars plana vitrectomy (PPPV) in the treatment of more complex rhegmatogenous retinal detachment (RRD) without scleral buckling (SB).Methods: 40 patients (40 eyes) with more complex primary rhegmatogenous retinal detachment were included in this study. For all patients: proliferative vitreoretinopathy (PVR) grade were B to C2 and the sizes, shapes, locations, amounts of the retinal tears / holes were more complex. The patients were divided into two groups randomly: one group treated by PPV (PPV Group) while the control one treated with SB (SB Group). Surgical techniques: For the PPV Group, standard three-port pars plana vitrectomy was performed, in which heavy water utilized to flatten the detached retina and endolaser coagulation applied to treat the retinal breaks and degeneration. Cryocoagulation was combined in some cases that the endolaser coagulation not enough for closing the retinal breaks. Intraocular tamponade with C₃F₈ or C₂F₆ was performed after air/liquid exchange; For SB Group, traditional scleral buckling were applied, in which the subretinal fluid was released and the retinal tears were cryocoagulated through indirect ophthalmoscopy. Disinfect air injected into vitreous cave or not was due to the intraocular pressure (IOP). Body position was prescribed to all patients according to the sites of the retinal tears. Some cases needed coagulation postoperatively. All the patients were followed up for 6 -14 months and the average time in PPV Group and SB Group were 9.89±3.67 months and 10.06±3.51months respectively. The data collected included visual acuity, the condition of the retina and the retinal tears, IOP, axial length of the eyeball, corneal curvature and refraction preoperatively and postoperatively.Postoperative complications also were collected. All the data were analyzed by SPSS 13.0.Results: 1. The retinal reattached rate of PPV group and SB group were 95% (19 cases) and 100% (20 cases) respectively. 16 cases (80%) of PPV group and 17 cases (85%) of SB group got reattached retina through only one time operation. 3cases in each group could get reattached retina through reoperation. The retinal reattached rate between the two groups has no statistic difference(P_one=0.676, P_re=1.000; P< 0.05). 2. The best corrected visual acuity had increased in 17 cases (85%) of the PPV group , among them that of 10 cases(20%) had improved 2-5 lines, 7 cases (35%) had improved over 5 lines,even that of 2 eyes had achieved 0.8, and it hadn't changed in 2 eyes, decreased in 1 eyes. But it had increased only in 14 eyes of the SB group, among them that of 10 eyes (50%) had improved 2-5 lines, only 1 eyes(5%) had improved over 5 lines, the maximum corrected visual acuity was only 0.5 while it hadn't changed in 6 eyes, decreased in 3 eyes. The rate of the best corrected visual acuity of PPV group was significantly higher than that of SB group (P=0.0383, P<0.05). The rate of the eyes which the best corrected visual acuity had improved over 5 lines of PPV group was also statistically higher than that of SB group (P=0.0479, P<0.05).3. (1)Compared with preoperative data, the length of axis oculi, the corneal astigmatism and the refraction of PPV group in 1month and 3months postoperatively had no statistically change (P_axis=0.9771,P_astigmatism=0.8262, P_refraction=0.9532, P>0.05). (2)For SB group, the length of the axis oculi of the operation eye increased postoperatively, but the difference had no statistical significance (P=0.1818, P>0.05) while the corneal astigmatism statistically increased either in 1 month or in 3 months postoperatively (P_1month=0.005, P_3month =0.0357 , P<0.05). The refraction developed myopia shift postoperatively. But the differences had statistical significances only in 1 month postoperatively (P₁=0.012, P<0.05),but not in 3 month postoperatively (P₃=0.2034, P>0.05). (3)The variation values of SB group were significantly greater than those of PPV group when the postoperative data compared with preoperative data (P_axis-1month=0.000,P_{astigmatism-1month}=0.000,P_{refraction-1month}=0.000,P_axis-3mongth=0.000,P_{astigmatism-3month}=0.014, P_{refraction-3month}= 0.000, P<0.05) ).4. Complications: The incidence rates of the earlier period cataract and the high intraocular pressure (IOP) of PPV group were higher than those of the SB group statistically (χ²_catract=21.5385,P=0.000;χ²_iop=4.2857,P=0.0383; P<0.05). The incidence rates of the macular retinal fold and dysmorphopsia of the PPV group were significantly lower than those of the SB group(χ²_fold=4.444,P=0.0349;χ²_{dysmorphopsia} =29.5652, P=0.000, P<0.05). But there was no significant difference in the incidence rates of the PVR, corneal edema and retinal hemorrhage between the two groups(χ²_PVR=1.111,P=0.2912;χ²_edema=2.0571, P=0.151;χ²_hemorrhage=0.000, P=1.000; P>0.05).Conclusions: Primary pars plana vitrectomy is safe, effective and reliable in the treatments of more complex RRD. It can result in sooner recovery, better vision and fewer complications.