Improving the ablastic capacity of intravitreal chemotherapy for retinoblastoma

Background: Intravitreally (IV) administered cytostatics are believed to be a promising local chemotherapy for retinoblastoma (RB) because this approach enables the highest level of chemotherapeutic agent after its direct injection into the ocular cavity. Intravitreal administration is, however, invasive. Among the factors that prevent the wide use of intravitreal chemotherapy (IVitC) for RB is the risk of intraocular complications. In addition, exteriorization of the intraocular tumor may occur through the injection channel or extrabulbar tumor spread may occur. Purpose: To develop a technique of IVitC for intraocular RB to improve its ablastic capacity through the prevention of extrabulbar tumor spread. Material and Methods: An ablastic technique of IVitC was developed at the Department of Pediatric Eye Disorders, the Filatov institute, and used to perform 253 IV injections in 30 children (37 eyes) with T1 to T3 retinoblastoma. Results: The advantages of the newly developed IVitC technique are as follows: achieving ocular hypotony without additional paracentesis; preventing reflux from the vitreous cavity by displacing the conjunctiva above the intravitreal entry point and forming an obliquely perpendicular injection channel; treating the site of scleral puncture with cotton swab tamponade and applying antibiotic solution subconjunctivally; preventing an infection of the vitreous and scleral thinning in repeat IVitC. There were no perioperative or postoperative complications. In addition, there were no signs of extrabulbar tumor spread during follow-up after IVitC. The number of IV injections per eye ranged from 1 to 13. Conclusion: An improved ablastic capacity of the developed IVitC technique was achieved by reducing (a) reflux from the vitreous through a number of above manipulations and (b) traumatic effect of intervention, as well as preventing complications, which enabled the minimal invasiveness and safety of the technique

Infrared thermography of external ocular surface in patients with absolute glaucoma in transscleral cyclophotocoagulation: a pilot study

Background: Changes in the temperature of external ocular surface in patients with absolute neovascular glaucoma (including the changes after transscleral contact cyclophotocoagulation with scleral compression (TCCSC)) are still to be investigated. Purpose: To use infrared thermography (1) to investigate thermal patterns and to estimate the temperature of the external ocular surface in healthy individuals and (2) to compare these characteristics in the glaucomatous eyes versus intact fellow eyes of patients with absolute glaucoma undergoing treatment with 1064-nm TCCSC. Materials and Methods: Twenty healthy volunteers (40 eyes) and 45 patients (90 eyes) with absolute glaucoma were under observation. All 130 eyes underwent visual acuity assessment, anterior eye photography, and infrared thermography of the external corneal surface. Each patient underwent three sessions of 1 064-nm TCCSC. Results: In healthy subjects, mean external ocular surface temperature was 34.5 ± 0.7°C. For patients with absolute glaucoma, external corneal surface temperature at baseline was higher in intact fellow eyes than in glaucomatous eyes (34.3 ± 0.9°C versus 33.1 ± 0.8°С, P = 0.0008). In addition, increases in the temperature of external ocular surface were observed in the course of decrease in IOP after 1 064-nm TCCSC. Conclusion: In patients with absolute glaucoma, infrared thermography found a marked thermal pattern asymmety between glaucomatous eyes and intact fellow eyes. In addition, increases in the temperature of external ocular surface in the course of decrease in IOP after 1064-nm TCCSC may be apparently attributed to improved ocular blood flow and inflammatory response of the ciliary body to laser photocoagulation