Transconjunctival 20-Gauge Vitrectomy: A Pilot Study

Abstract

Purpose: To determine the efficacy of a novel technique for a ‘transconjunctival 20-gauge vitrectomy’ (T20V). Methods: In total, 12 eyes of 12 consecutive patients were included in a prospective study. The mean age was 58 years (range: 38–74 years); 4 patients were male and 8 were female. The T20V was indicated when short-duration vitrectomy was envisioned: macular surgery for macular hole and epiretinal membrane therapy, moderate vitreous hemorrhage due to retina vein occlusions or diabetic retinopathy, or neurotomy for central retinal vein occlusion. Results: The average time for each procedure was 35 ± 30 min (SD). The preoperative visual acuity ranged from 20/200 to hand motions, while postoperative vision was between 20/30 and counting fingers. The average intraocular pressure changed from 16.1 ± 5.6 mm Hg preoperatively to 15.8 ± 8.1 mm Hg in the first postoperative day, and 17.8 ± 9.4 mm Hg 1 week after surgery – these differences were not statistically significant (p > 0.05). Subjective postoperative pain and foreign body sensation at postoperative day 1 and week 1 were mild to moderate. The chemosis observed 1 h after surgery was minimal, and disappeared quickly during the 1-week follow-up. Conclusion: The T20V is suitable to perform short-duration vitrectomy surgery, and has a low rate of ocular complications, similar to 25- or 23-gauge sutureless vitrectomy systems.

Outcome of 20-gauge transconjunctival cannulated sutureless vitrectomy using silicone oil or air tamponade

“…Our series had no cases of postoperative vitreous hemorrhage in either group in comparison with the study reported by Aguni et al, which showed mild vitreous hemorrhage in 25% of cases; however, these all spontaneously cleared up within weeks 14. We also had no cases of vitreous incarceration at the sclerotomy, whereas Aguni et al did have one case of this 14…”

“…Disadvantages of the trocar system include the longer intraoperative time, a slightly higher risk of scleral wound trauma, and the increased cost of the surgery 13,14…”

Corneal topographic changes following trans-conjunctival 20 gauge sutureless vitrectomy (TC20V)

“…The induced astigmatism is usually transient and returns to the baseline level by 1 to 4 months after surgery. The increase in the postoperative astigmatism may be attributed to the scleral cautery and suturing at the entry port 4–6. Yanyali et al concluded that regular and irregular astigmatism of the cornea did not change when 25-gauge TSV was used 7…”

Scleral Incisions Evaluated By with Anterior Segment Optical Coherence Tomography

“…Both studies suggested that oblique incisions in a beveled or tunneled fashion provide better wound apposition and stability compared to straight incisions. Oblique scleral incisions promoted also for "transconjunctival 20gauge vitrectomies" a safe approach, 3 while straight or tangential injections may remain open, inducing leakage and ocular hypotony even with 30-gauge needles. 4 Oblique or angled incisions are believed to decrease wound leakage by having an internal lip that presses against the outer lip through the elevated intraocular pressure, helping to close the wound.…”