Outcomes of transconjunctival sutureless 27-gauge micro-incision vitrectomy surgery in diabetic vitreous haemorrhage

27‑Gauge vitrectomy vs. 25‑gauge vitrectomy in the management of proliferative diabetic retinopathy with preoperative intravitreal injection of conbercept

Small-gauge vitrectomy has become popular due to its notable advantages, including less trauma, shortened convalescence and improved manoeuvrability. The aim of the present study was to compare the surgical outcomes of 27-gauge (27-G) vitrectomy with those of 25-gauge (25-G) vitrectomy in the management of proliferative diabetic retinopathy (PDR) with preoperative intravitreal injection of conbercept. The data of 48 consecutive patients with PDR (48 eyes) were retrospectively collected. The patients underwent conbercept intravitreal injection and pars plana vitrectomy with a 27-G group (23 eyes) or 25-G group (25 eyes) vitrectomy system. The operating time, suturing rate, endodiathermy rate, postoperative best-corrected visual acuity (BCVA), intraocular pressure (IOP) and complications were recorded. The mean postoperative BCVA at final follow-up was significantly improved compared with that at the baseline in both groups (P<0.001 for both). The differences in the mean BCVA changes between the two groups were not significant (P>0.99), and no differences were observed in the final central foveal thickness (P=0.51) between the two groups. The final IOP remained stable compared with that at the baseline in the 27-G group (P=0.36) and the 25-G group (P=0.05). The suturing rate was significantly decreased in the 27-G group compared with the 25-G group (P=0.04). There were no significant differences between the two groups in terms of the operating time (P=0.18), rate of endodiathermy use (P>0.99), iatrogenic retinal breaks (P=0.42) or postoperative recurrent vitreous haemorrhage (P>0.99). In addition, no case of ocular hypotony was observed in either group. In conclusion, 27-G vitrectomy was as efficient and safe as 25-G vitrectomy in the management of PDR in terms of operating time and complications. With reference to the literature, preoperative conbercept injection appears to assist in decreasing the incidence of intraoperative and postoperative complications.

Impact of different manufacturers and gauge sizes on the performance of backflush needle

The present study aimed to identify the factors regulating aspiration rate (AR) of backflush needles and to compare those factors across various backflush needles from different manufacturers. The 27-gauge (27G), 25-gauge, and 23-gauge backflush needles from four different manufacturers, Alcon, MedOne, VitreQ, and DORC, were used for this experiment. AR was measured at four different aspiration vacuum levels: 100, 200, 400, and 650 mmHg. AR was significantly increased as the aspiration vacuum level increased when both aspirating balanced salt solution (BSS) and ethylene glycol; however, 27G products from VitreQ and MedOne were unable to aspirate ethylene glycol at the low aspiration vacuum level of 100 mmHg. When aspirating BSS at the high aspiration vacuum level of 650 mmHg, a smaller gauge number generally resulted in a significantly higher AR. AR, inner diameter, and cross-sectional area in Alcon products were significantly larger in any gauge, and the shaft length of Alcon products was significantly shorter than those of other manufacturers’ products in any gauge. Cross-sectional area negatively correlated with the degree of shaft deflection (r² = 0.21, p = 0.042). These results imply that AR differs significantly among backflush needles and among companies depending on the shaft cross-sectional area.

Surgical outcomes of 27-gauge and 25-gauge vitrectomy day surgery for proliferative diabetic retinopathy

PURPOSE

To compare postoperative outcomes of 27-gauge (G) and 25-G vitrectomy conducted as day surgery for proliferative diabetic retinopathy (PDR).

METHODS

One hundred eighty-five consecutive PDR patients (185 eyes) who underwent primary vitrectomy (27-G in 64 eyes, 25-G in 121 eyes) were analyzed.

RESULTS

The 27-G and 25-G groups did not differ significantly in preoperative Early Treatment Diabetic Retinopathy Study (ETDRS) score, age, or preoperative intraocular pressure. The proportions of simultaneous cataract surgery (27-G vs. 25-G: 59.4% vs. 62.4%) and air-filled eyes (76.6% vs. 85.1%) were not significantly different between two groups. Both groups showed significant improvement in ETDRS score at postoperative 1, 3, and 6 months (all, P < 0.0001). Mean gain in ETDRS score from baseline was apparently better in 27-G group than in 25-G group at 1, 3, and 6 months, but there were no significant differences (1 month: 20.3 vs. 13.1 letters, P = 0.0703; 3 months: 22.9 vs. 17.5 letters, P = 0.1561; 6 months: 24.3 vs. 19.3 letters, P = 0.3313). Operation time was apparently longer for 27-G vitrectomy, but there was no significant difference (54.0 vs. 51.1 min, P = 0.3676). The same was observed for postoperative intraocular pressure at postoperative day 1 (19.7 vs. 18.1 mmHg, P = 0.1353). Incidence of postoperative retinal detachment (1.6% vs. 0.8%) and reoperation due to vitreous hemorrhage (6.3% vs. 6.6%) was not different between two groups.

CONCLUSIONS

The 27G system is as safe and as useful as the 25G system when used for PDR and can be expected to achieve earlier recovery of postoperative visual acuity.

Retrospective Comparison of 27-Gauge and 25-Gauge Microincision Vitrectomy Surgery with Silicone Oil for the Treatment of Primary Rhegmatogenous Retinal Detachment

Aim

To retrospectively compare the safety and effectiveness of 27-gauge (27G) microincision vitrectomy surgery (MIVS) with 25-guage (25G) MIVS for the treatment of primary rhegmatogenous retinal detachment (RRD) with silicone oil tamponade.

Methods

Ninety-two patients with RRD who underwent MIVS from May 1, 2015, to June 30, 2017, were included in this study. Fifty-eight eyes underwent 25G MIVS and 34 eyes underwent 27G MIVS. We analyzed the characteristics of the patients, surgical time, main clinical outcomes, and rate of complications.

Results

The mean surgical time was 56.7 ± 35.9 min for the 25G MIVS and 55.7 ± 36.1 min for the 27G MIVS, and there was no significant difference (P=0.894) between the two groups. The primary anatomical success rate after a single operation was 94.8% for 25G MIVS and 91.2% for 27G MIVS (P=0.666). Baseline and final visit best-corrected visual acuity (BCVA) were 1.9 ± 1.1 and 1.0 ± 0.8 in the 25G group, and 1.7 ± 1.0 and 1.1 ± 0.8 in the 27G group. Last visit BCVA increased significantly in both groups (P < 0.001). However, there were no significant differences in terms of visual improvement ratio (>0.2 logMAR) between the two groups (P=0.173). No severe intraoperative complication was observed. Iatrogenic retinal breaks occurred in 2 eyes (3.4%) in the 25G group and 1 eye (2.9%) in the 27G group during the peripheral vitreous base shaving. The transient ocular hypertension (>25 mmHg) within postoperative week 1 was 25.9% in the 25G group and 11.8% in the 27G group (P=0.120).

Conclusions

This study found no significant anatomical or functional difference between 27G and 25G MIVS in the treatment of primary RRD. Therefore, 27G vitrectomy appears to be a safe and effective surgery for the treatment of primary RRD.