Discussion
PDR, hemorrhagic complications, ’ blood glucose, retinal detachment, retinal neovascularization, vitreous hemorrhage, hypertension
POSTOPERATIVE HYPOTENSION, RETINA, RETINAL DAMAGE, ADHESION, ADVERSE EVENT, PROLIFERATIVE, RETINAL NEOVASCULARIZATION, RETINAL DETACHMENT, VITREOUS HEMORRHAGE, LEAKAGE, HYPERTENSION, COMPLICATIONS
Due to retinal neovascularization in PDR patients, vitreous hemorrhage and proliferative membranes occur frequently. The latter applies traction to the retina and easily results in retinal detachment [Regarding MIVS for PDR treatment, most people believe that a smaller VP can more easily enter the gap below the proliferative membrane to achieve an accurate operation. However, some studies have shown that the traditional 27G vitrectomy system does not have many advantages over other systems [According to the existing clinical and fluidics studies, due to its small gauge, the conventional 27G vitrectomy system may take a longer time to cut the vitreous, which can also affect the overall surgical process [In other aspects of the surgery, the proportion of eyes with postoperative scleral suture in the 27G group was significantly lower. This has also been reported in other studies on traditional MIVS systems [In terms of postoperative outcomes, compared with that at baseline, the BCVA of all patients gradually improved at 1 week, 1 month, 3 months and 6 months after surgery. The degree of improvement was similar between the two groups. Furthermore, except for a significant elevation at 1 week after the surgery, the IOP was maintained at normal levels at most time point. However, temporary intraocular hypertension is not a serious adverse event [The safety of surgery is also a topic of concern for surgeons. According to the analysis of the data, the 27G group produced fewer hemorrhagic complications and needed less electrocoagulation, which could ensure a clear surgical field, as well as reduce retinal damage. During the 6-month follow-up period, there were no serious complications except for occasional recurrent vitreous hemorrhage. We believe that it is closely related to the patients’ blood glucose and other indicators, so more emphasis should be placed on patient education. To our surprise, the proportion of postoperative hypotension in the 27G group was slightly higher even though a smaller incision was made. We speculate that to ensure no serious leakage, more patients in the 25G group underwent scleral suturing. This may have been the reason for their IOP stability in the short term postoperatively. However, after observation with some potential intervention, the IOP of all patients returned to normal. The above results showed that the safety of the two vitrectomy systems was similar, and both of them can provide safe treatment for PDR patients.Currently, there have not been many prospective comparative clinical studies on the treatment of PDR patients with beveled-tip MIVS. We found some unique advantages with this system in this specific operation and affirmed its effectiveness and safety. Moreover, we observed the productivity of cutting the membrane with a novel quantitative method. As described in previous literature, it was estimated based on the operation time, which might be affected by several confounding variables that could result in measurement error. This method can more objectively and visually present the results. However, there are also some limitations in this study. Due to the limited number of patients, we compared only two types of vitrectomy systems. Some ophthalmologists consider 25G MIVS as the first choice for surgery for PDR because of the faster vitreous cutting and greater hardness, so the 25G flat-tip MIVS was set as the control group. Therefore, the effect of gauge and cutting rate on the results cannot be excluded in the study. In addition, when we assessed the severity of the proliferative membrane at baseline, factors such as the degree of adhesion between the membrane and retina or the thickness of the membrane were not considered, which may have influenced the experimental outcomes.