Infection prophylaxis with silastic sponge explants in retinal detachment surgery

Organo-Selenium Coatings Inhibit Gram-Negative and Gram-Positive Bacterial Attachment to Ophthalmic Scleral Buckle Material

Purpose

Biofilm formation is a problem for solid and sponge-type scleral buckles. This can lead to complications that require removal of the buckle, and result in vision loss due to related ocular morbidity, primarily infection, or recurrent retinal detachment. We investigate the ability of a covalent organo-selenium coating to inhibit biofilm formation on a scleral buckle.

Methods

Sponge and solid Labtican brand scleral buckles were coated with organo-selenium coupled to a silyation reagent. Staphylococcus aureus biofilm formation was monitored by a standard colony-forming unit assay and the confocal laser scanning microscopy, while Pseudomonas aeruginosa biofilm formation was examined by scanning electron microscopy. Stability studies were done, by soaking in phosphate buffer saline (PBS) at room temperature for 2 months. Toxicity against human corneal epithelial cell was examined by growing the cells in the presence of organo-selenium–coated scleral buckles.

Results

The organo-selenium coating inhibited biofilm formation by gram-negative and gram-positive bacteria. The buckle coatings also were shown to be fully active after soaking in PBS for 2 months. The organo-selenium coatings had no effect on the viability of human corneal epithelial cells.

Conclusions

Organo-selenium can be used to covalently coat a scleral buckle, which is stable and inhibits biofilm formation for gram-negative and gram-positive bacteria. The organo-selenium buckle coating was stable and nontoxic to cell culture.

Translational Relevance

This technology provides a means to inhibit bacterial attachment to devices attached to the eye, without damage to ocular cells.

Suprachoroidal septic effusion leading to panophthalmitis following strabismus surgery

We describe a case of endophthalmitis following strabismus surgery. Drainage of the suprachoroidal effusion with injection of antibiotics was unsuccessful in salvaging vision. Endophthalmitis following strabismus surgery may present with findings simulating a choroidal effusion or hemorrhage. Treating physicians should be alert to signs and symptoms of this severe complication of strabismus surgery in preverbal children.

Biofilm and scleral buckle-associated infections. A mechanism for persistence

Scleral buckle infections tend to be persistent as well as resistant to antimicrobial treatment. Often, scleral buckle infections require removal of the buckling elements for resolution. To determine if bacteria are able to persist on scleral buckles by elaborating a glycocalyx matrix or biofilm that offers protection against host defenses and antimicrobial treatment, the authors cultured 28 scleral buckle elements removed for infection and extrusion. Bacteria were isolated from 18 elements (64%). The most frequently isolated bacteria were Staphylococcus epidermidis and other coagulase-negative staphylococci (8), Staphylococcus aureus (3), corynebacteria (3), Mycobacterium chelonei (3), and Proteus mirabilis (3). Eleven (65%) of 17 buckles evaluated with scanning electron microscopy demonstrated the presence of bacteria encased in biofilm. Biofilm was demonstrated on the surfaces and ends of solid silicon elements. In the silicon sponges, biofilm also extended into the matrix of the sponges. The authors believe that bacterial production of biofilm offers an explanation for the persistence of scleral buckle infections and their ability to withstand antimicrobial treatment.

Pneumatic retinopexy. A two-step outpatient operation without conjunctival incision

1,000 consecutive patients operated for retinal detachment were studied prospectively to determine the incidence of complications. Two parts of the operation were responsible for most of the vision-threatening complications: subretinal fluid drainage and the scleral buckle. In an attempt to reduce the complications of retinal detachment surgery, we have utilized a simplified procedure of transconjunctival cryotherapy and intravitreal gas injection with postoperative positioning. This study was limited to detachments with one or more breaks within one clock hour located within the superior eight clock hours of the fundus without signs of proliferative vitreoretinopathy. In a series of 20 consecutive patients, retinal reattachment was initially achieved in all cases. There were two recurrences that were reattached with scleral buckling. The final cure rate for the single pneumatic procedure, with six months follow-up, was 90%. No major complications were observed. This preliminary report suggests that pneumatic retinopexy has the advantages of reduced tissue trauma, no hospitalization, minimal complications, and reduced expense. The major disadvantage is the need for postoperative positioning for five days.

Preoperative antibiotic soaking of silicone sponges. Does it make a difference?

A prospective randomized trial was carried out during the years 1974 to 1981 to determine whether preoperative antibiotic soaking of silicone sponges used in retinal detachment surgery would reduce the incidence of postoperative infection and extrusion. During this period 2972 consecutive primary scleral buckles were performed and in 921 (31%) of the cases an episcleral sponge was utilized either alone or in conjunction with a hard silicone encircling band. In alternate cases the sponge was soaked in an antibiotic solution for at least 30 minutes prior to insertion. In the remaining cases the sponge was not soaked. Overall, a statistically significant (P = 0.00018) seven-fold reduction in the rate of infection or extrusion was observed in cases where the silicone sponge was soaked preoperatively in antibiotics. An additional result of the study showed the rate of sponge removal was significantly increased by the use of multiple episcleral sponges (P = 0.00002).