Jeffrey N. Bloom

Retinal Perforation in Strabismus Surgery

PURPOSE Perforation of the retina is a major complication of strabismus surgery. The reported incidence of perforation varies from 0.13% to 12%. This study was undertaken to determine, from a large collaborative database, the incidence of suspected and unsuspected retinal and choroidal injury in pediatric horizontal muscle surgery. METHOD All children with horizontal strabismus surgery seen between September 1992 and October 1995 were examined with Indirect ophthalmoscopy immediately following their procedure. Surgery was performed by both resident and attending physicians. Cases involving muscle reoperation, high myopia, or patients with connective tissue disorders were excluded. RESULTS Strabismus surgery was performed on 765 patients, who underwent 1129 muscle recessions and 349 muscle resections. These children also had 161 vertical or oblique muscle procedures performed. Intraocular trauma resulting from horizontal muscle surgery was noted in 14 patient, including three retinal perforations. One of these patients was treated with cryotherapy; the other two received no therapy other than intraoperative and postoperative antibiotics. DISCUSSION The incidence of retinal perforation was 0.4% and the incidence of choroidal injury without perforation was 1.4% in this large series of children undergoing horizontal strabismus surgery. Retinal detachment or endophthalmitis did not develop during the 6-week follow-up period.

LIPOSOME-ENCAPSULATED CLODRONATE RETARDS THE DEVELOPMENT OF EXPERIMENTAL AUTOIMMUNE UVEITIS

AbstractA study was undertaken to determine if the intravenous injection of liposome-encapsulated dichloromethylene diphosphonate (C12MDP; Clodronat), a treatment known to deplete monocytes, as well as liver and spleen macrophages, would reduce the number of macrophages in the retina of animals with experimental autoimmune uveitis (EAU) and decrease the severity of the disease. EAU was induced in Lewis rats by immunization with S-antigen (S-Ag). Monocytes and macrophages were depleted via an intravenous injection of Cl2MDP encapsulated in liposomes. Control groups included rats that received no S-Ag (n= 18), S-Ag and no treatment (n=23), S-Ag and free drug (n = 20), or empty liposomes (n=14). Treated animals received injections of the Cl2MDP-liposomes, free drug, or empty liposomes. Animals were sacrificed at 14, 21 and 28 days post-S-Ag administration. Intravenous, Cl2MDP-liposomes produced a statistically significant reduction in the severity of the EAU when compared to controls at both days 14 and 21 f...

Composites containing albumin protein or cyanoacrylate adhesives and biodegradable scaffolds: I. Acute wound closure study in a rat model

Our Scaffold-Enhanced Biological Adhesive (SEBA) system was investigated as an alternative to sutures or adhesives alone for repair of wounds. Two scaffold materials were investigated: (i) a synthetic biodegradable material fabricated from poly(L-lactic-co-glycolic acid); and (ii) a biologic material, small intestinal submucosa, manufactured by Cook BioTech. Two adhesive materials were also investigated: (i) a biologic adhesive composed of 50%(w/v) bovine serum albumin solder and 0.5mg/ml indocyanine green dye mixed in deionized water, and activated with an 808-nm diode laser; and (ii) Ethicon’s Dermabond, a 2-octyl-cyanoacrylate. The tensile strength and time-to-failure of skin incisions repaired in vivo in a rat model were measured at seven days postoperative. Incisions closed by protein solder alone, by Dermabond alone, or by suture, were also tested for comparison. The tensile strength of repairs formed using the SEBA system were 50% to 65% stronger than repairs formed by suture or either adhesive alone, with significantly less variations within each experimental group (average standard deviations of 15% for SEBA versus 38% for suture and 28% for adhesive alone). In addition, the time-to-failure curves showed a longevity not previously seen with the suture or adhesive alone techniques. The SEBA system acts to keep the dermis in tight apposition during the critical early phase of wound healing when tissue gaps are bridged by scar and granulation tissue. It has the property of being more flexible than either of the adhesives alone and may allow the apposed edges to move in conjunction with each other as a unit for a longer period of time and over a greater range of stresses than adhesives alone. This permits more rapid healing and establishment of integrity since the microgaps between the dermis edges are significantly reduced. By the time the scaffolds are sloughed from the wound site, there is greater strength and healing than that produced by adhesive alone or by wounds following suture removal. This hypothesis is supported by the data of this study, as well as, the acute tensile strength data of Part I of this study.

A scaffold-enhanced light-activated surgical adhesive technique: surface selection for enhanced tensile strength in wound repair

An ex vivo study was conducted to determine the effect of the irregularity of the scaffold surface on the tensile strength of repairs formed using our Scaffold-Enhanced Biological Adhesive (SEBA). Two different scaffold materials were investigated: (i) a synthetic biodegradable material fabricated from poly(L-lactic-co-glycolic acid); and (ii) a biological material, small intestinal submucosa, manufactured by Cook BioTech. The scaffolds were doped with protein solder composed of 50%(w/v) bovine serum albumin solder and 0.5mg/ml indocyanine green dye mixed in deionized water, and activated with an 808-nm diode laser. The tensile strength of repairs performed on bovine thoracic aorta, liver, spleen, small intestine and lung, using the smooth and irregular surfaces of the above scaffold-enhanced materials were measured and the time-to-failure was recorded. The tensile strength of repairs formed using the irregular surfaces of the scaffolds were consistently higher than those formed using the smooth surfaces of the scaffolds. The largest difference was observed on repairs formed on the aorta and small intestine, where the repairs were, on average, 50% stronger using the irregular versus the smooth scaffold surfaces. In addition, the time-to-failure of repairs formed using the irregular surfaces of the scaffolds were between 50% and 100% longer than that achieved using the smooth surfaces of the scaffolds. It has previously been shown that distributing or dispersing the adhesive forces over the increased surface area of the scaffold, either smooth or irregular, produces stronger repairs than albumin solder alone. The increase in the absolute strength and longevity of repairs seen in this new study when the irregular surfaces of the scaffolds are used is thought to be due to the distribution of forces between the many independent micro-adhesions provided by the irregular surfaces.