We had proposed the short-term external buckling with pneumatic retinopexy as a novel and effective treatment for rhegmatogenous retinal detachment (RRD) with inferior retinal breaks, with a comparable success rate to other treatment methods.

Xiao and associates had questioned the role of vitreous traction and the need for pneumatic retinopexy for these patients. Surely vitreous traction is an important and major causative factor of RRD. The concern about the possibly persistent vitreous traction after the removal of the external buckle had also been mentioned in our study.

Will vitreous traction be released after pneumatic retinopexy? Will it be further lessened after external buckling, though transient in our study?

Lincoff and associates reported that the cortical vitreous of the normal cynomolgus monkey eyes appeared to be a lamellar structure composed of sheets of collagen mesh. But in the perfluorocarbon gas–treated eyes, there was shrinking and tearing of the lamellae. Hikichi and associates reported, in eyes with retinopathy of prematurity (ROP) that underwent retinal cryopexy and/or photocoagulation, that the extensive vitreous liquefaction that affected a large segment of the vitreous was present in all the eyes. It was also reported that intraocular gas injection, such as intravitreal injection of perfluoropropane gas (C ₃ F ₈ ) in our study, may result in vitreous dissection and enhance posterior vitreous detachment during the days immediately after gas injection, which had been shown on optical coherence tomography (OCT).

From the clinical observation, most of the vitreous traction was released after the processing in our study; however, we did not have OCT results for proof currently. Actually, it is still difficult to perform an OCT investigation for far peripheral vitreoretina. The vitreous conformation is also difficult to describe without vitreous window enhancement by commercially available OCT. Thus, we suggested that the patients should be followed up closely during the critical period between the removal of the buckle and the formation of stable chorioretinal adhesion for the uncertainty.

Though it is known that the buckle itself can provoke reabsorption of subretinal fluid in RRD, the role of intraocular gas injection is essential. As mentioned in our study, gas provides a further tamponading force from inside and helps to seal the breaks. The contact surface between gas and retina may be increased with the aid of the external buckling and the face-down position with 5 to 10 degrees of neck flexion. Transconjunctival cryopexy and laser retinopexy were also important to provide a secure chorioretinal adhesion in our study for sealing the inferior retinal breaks.

We do not know whether applying an external buckle only, to treat RRD with inferior retinal breaks, will have successful results or not. In our study, it was necessary to employ pneumatic retinopexy and external buckling. Further investigation is warranted.