Ultrasound biomicroscopy study of vitreous incarceration subsequent to intravitreal injections

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.

Cytopathological Evaluation of Ocular Surface and Needle Washings Following Intravitreal Melphalan Injections for Retinoblastoma

PURPOSE

There is concern that injections into eyes with retinoblastoma are dangerous and allow tumor escapement. This study attempted to determine this risk by investigating the presence of malignant cells in ocular surface and needle washings of eyes with retinoblastoma receiving intravitreal injections.

METHODS

Two hundred ocular surface and 202 needle washings were obtained from 280 injections into eyes with retinoblastoma. Each specimen underwent cytopathlogical assessment for the presence of malignant cells.

RESULTS

Cytopathological results revealed no malignant cells in all 200 ocular surface and 202 needle washing specimens. In the ocular surface washings, squamous cells, red blood cells, and inflammatory cells were found in 15, 2, and 2 specimens, respectively. In the needle washings, 4 specimens contained squamous cells but no red blood cells or inflammatory cells were found in any specimen.

CONCLUSION

With this injection and evaluation technique, no malignant cells were recovered, highlighting the low risk of the procedure. [J Pediatr Opthalmol Strabismus. 20XX;XX(XX):XX-XX.].

Vitreous incarceration after ranibizumab injection: an ultrasound biomicroscopy study

BACKGROUND AND OBJECTIVE

The aim of the study was to evaluate vitreous incarceration at the injection site using ultrasound biomicroscopy (UBM) after intravitreal injection of ranibizumab.

PATIENTS AND METHODS

The study included 39 eyes of 34 patients who underwent intravitreal injection of 0.05 mL of ranibizumab. UBM (HiScan; Optikon, Rome, Italy) with a 50 MHz probe was performed 1 day after surgery to determine the existence of vitreous incarceration at the injection site.

RESULTS

The mean patient age was 59.7 (± 10.1) years, and 58.9% were female. Vitreous incarceration into the pars plana site was detected in six eyes (15.3%) the day after intravitreal injection.

CONCLUSION

Vitreous incarceration at the injection site after intravitreal injection is thought to lead to a higher risk for complications such as infection, retinal breaks, retinal detachment, vitreous hemorrhage, and fibrovascular proliferation at the injection site. To understand the clinical importance of vitreous incarceration, further long-term prospective studies are necessary.