The aim of this study is to evaluate the efficacy of pure perfluoropropane (C3F8) tamponade combined with vitrectomy (PPV) in the treatment of retinal detachment (RD).

Ninety-seven patients (97 eyes) with RD who underwent 23G PPV combined with C3F8 tamponade at the Department of Ophthalmology of Peking University Third Hospital from March to November 2022 were selected as the research subjects. Among them, there were 45 males (45 eyes) and 52 females (52 eyes) ranged from 41 to 71 years with an average age of (56.5±15.2) years. According to the gas tamponade type, the patients were divided into pure gas group with 33 cases (33 eyes) and mixed gas group with 64 cases (64 eyes). All patients were treated by gas tamponade combined with PPV, and the pure gas group was given an appropriate amount of 100% C3F8, and the mixed gas group was given a mixture of non-expanding concentration of C3F8 and sterile air. The best corrected visual acuity (BCVA), intraocular pressure, axial length, the last retinal reattachment rate after operation and postoperative ocular inflammation were determined and recorded. The BCVA, intraocular pressure, axial length were in accordance with the normal distribution, described by ±s, and compared by the independent sample t test for inter-group and paired sample t test for intra-group before and after operation. The range of intraocular pressure and postoperative ocular inflammation in the two groups were described by the eyes number and percentage and compared by rank sum test for inter-group. Fisher′s exact test was used for the last retinal reattachment rate after operation. Repeated measurement data at multiple time points were analyzed by repeated measures ANOVA.

In the pure gas group, the time for intraocular gas preparation, gas injection and C3F8 consumption were (2.48±0.51)s, (5.09±1.21)s and (0.64±0.20)ml, respectively. In the mixed gas group, those were (16.62±6.20)s, (180.34±34.30)s and (4.69±2.59)ml, respectively, and the differences were statistically significant (t= -18.207, -40.836, -12.41; P<0.05). The last retinal reattachment rate was 97.0% in pure gas group and 98.4% in mixed gas group after operation for 6 months, and the difference was not statistically significant (P>0.05). There was no significant difference in the group effect of intraocular pressure between the two groups before surgery, immediately after surgery, after surgery for 1 day and 1 month (F_group=0.032, P>0.05). The time effect was statistically significant (F_time=23.215, P<0.05). The interaction effect was not statistically significant (F_interaction=1.735, P>0.05). In the pure gas group, there were 8 cases (8 eyes) with the highest intraocular pressure < 21 mmHg(1 mmHg=0.133 kPa), 14 cases (14 eyes) with the highest intraocular pressure from 21 mmHg to 30 mmHg, and 11 cases (11 eyes) with the highest intraocular pressure ≥30 mmHg, accounting for 24.2%, 42.4% and 33.3%, respectively. In the mixed gas group, there were 18 cases (18 eyes) with the highest intraocular pressure < 21 mmHg, 32 cases (32 eyes) with the highest intraocular pressure from 21 mmHg to 30 mmHg, and 14 cases (14 eyes) with the highest intraocular pressure ≥30 mmHg, accounting for 28.1%, 50.0% and 21.9%, respectively. There was no significant difference in the distribution of the highest intraocular pressure between the two groups (Z= -0.979, P>0.05). The BCVA of the pure gas group was better than that of the mixed gas group at the last follow-up, and the difference was statistically significant (t= -2.497, P<0.05). There was no significant difference in postoperative ocular inflammation between the pure gas group and the mixed gas group (Z= -1.430, P> 0.05).

Compared with the mixed gas tamponade group, the pure gas group has a better RD efficacy, no postoperative complications, and shows better postoperative BCVA. It can shorten the time of intraocular gas preparation and injection and reduce the dosage of C3F8.