AIM: To observe the outcome of intravitreal balanced salt solution(BSS)injection to increase intraocular pressure(IOP)after extrascleral subretinal fluid drainage, then scleral buckling(SB)to treat superior bullous retinal detachment(SBRD), and compare it with the effect of conventional surgery(without any intravitreal filling)and postoperative air filling.

METHODS: Retrospective case-control study. A total of 72 patients(73 eyes)who underwent SB for SBRD from January 2018 to December 2022 in ophthalmology department of Xijing Hospital were included. The extrascleral subretinal fluid drainage was performed in all eyes. According to whether intravitreal injection was performed and different injections, patients were divided into three groups: with 24 cases(24 eyes)in the conventional group(no intravitreal injection), 23 cases(23 eyes)in the air group(sterile air was injected after surgery), and 25 cases(26 eyes)in the BSS group(BSS was injected during extrascleral subretinal fluid drainage). All patients were followed up until subretinal fluid was absorbed completely. The average surgery time, postoperative IOP, retinal reattachment rate, subretinal fluid absorption, visual acuity(LogMAR)and major complications were compared.

RESULTS: All surgeries were completed successfully. The average surgery time of the conventional group, air group and BSS group were 63.17±13.22, 61.65±15.55 and 57.30±11.70 min, respectively. There had no significant difference among these groups(F=0.825, P=0.443). On the first post-operative day, the average IOP of the conventional group, air group and BSS group were 13.69±2.69, 16.40±2.86 and 18.35±2.88 mmHg, respectively. The average IOP of the air group and the BSS group were significant higher than that of the conventional group(F=17.18, P<0.001). Primary reattachment rates were 88%, 96%, and 100%, respectively. The postoperative BCVA was 0.71±0.42, 0.59±0.44, and 0.91±0.50, respectively, which were significantly higher than those before operation(all P<0.05), but there was no significant difference among groups(F=3.046, P>0.05). The main complications included subretinal hemorrhage in 1 eye from the conventional group and 1 eye from the air group, and a new retinal tear in 1 eye from the air group, resulting in localized retinal detachment.

CONCLUSIONS: For SBRD patients with hypotony during SB surgery, intravitreal injection of BSS to properly increase the IOP and then complete the surgery can improve the reattachment rate and reduce postoperative complications. This method is safe and effective for selected SBRD patients.