Vitreous incarceration after ranibizumab injection: an ultrasound biomicroscopy study

Outcomes of scleral buckling using chandelier endoillumination

PURPOSE

To report the results and complications of scleral buckling for the treatment of rhegmatogenous retinal detachment (RRD) using 25-gauge chandelier endoillumination.

METHODS

A total of 61 patients (61 eyes) with RRD were treated with scleral buckling. For the sclera buckling procedure, a 25-gauge chandelier was inserted through the pars plana for intra-ocular illumination, and retinal tears were identified and treated with episcleral cryotherapy under surgical microscope. On postoperative days 1, 3 and 7, the intra-ocular pressure was measured by a non-contact tonometer. On postoperative months 1 and 3, ultrasound biomicroscopy was used to examine the pars plana incision.

RESULTS

In the surgical procedure, there was no lenticular or retinal damage due to the chandelier insertion. There was no conjunctival bleb formation at pars plana incision and no incidence of endophthalmitis after surgery. The mean intra-ocular pressure was 15.74 ± 2.98, 15.83 ± 2.76 and 16.14 ± 2.52 mmHg on postoperative days 1, 3 and 7, respectively. The one-time retinal reattachment rate was 93.4%. No visible vitreous incarceration was found in the incision of the pars plana.

CONCLUSION

There was no complication found due to the chandelier insertion in early postoperative period. Chandelier endoillumination is a feasible method for retinal visualization under surgical microscope during scleral buckling.

EXPERIMENTAL VISUALIZATION AND QUANTIFICATION OF VITREOUS CONTAMINATION FOLLOWING INTRAVITREAL INJECTIONS

PURPOSE

To detect and quantify vitreous contamination after intravitreal injection using an experimental vitreous contamination model.

METHODS

Enucleated porcine eyes served as a Type 1 experimental vitreous contamination model with fluoresbrite carboxylate microspheres applied to the conjunctival surface. Saline solution (0.05 mL) was injected using a 27-, 30-, or 32-gauge (G) needle. Injection procedures were monitored using an intraocular fiber catheter. Condensed microspheres were applied to an excised sheet of porcine sclera (Type 2 experimental vitreous contamination model). Saline solution (0.05 mL) was injected from the top of an applied condensed microsphere through the sclera using a needle of one of the aforementioned gauges, and samples were then collected. The fluorescence strength of samples was measured using fluorophotometry.

RESULTS

We visually detected fluorescent microspheres in 10/10, 9/10, and 9/10 eyes injected with 27-G, 30-G, and 32-G needles, respectively. In the experimental quantification study, values at all needle gauges were significantly higher than those of controls (P < 0.01). Fluorescence strength was significantly higher in the 27-G group than in the 30- (P < 0.01) and 32-G (P < 0.01) groups.

CONCLUSION

Intravitreal injection carries the risk of introducing contamination directly into the eyes even when a 32-G needle is used. Furthermore, the 27-G needle carries the highest contamination risk.