A look into the techniques of retinal specialists shows that surgeons in the United States participate in a range of patient care techniques  before, during and after intravitreal injections. In order to better understand the intravitreal injection technique practice patterns of retinal specialists, researchers from the Mayo Clinic in Rochester, Minn., administered an anonymous, 20-question, Internet-based questionnaire to all members of the American Academy of Ophthalmology who categorized themselves as specialists in “Retinal/Vitreous Surgery.”

A total of 765 retinal specialists (44 percent) responded to the survey. Most respondents reported wearing gloves (58 percent) and using an eyelid speculum (92 percent) when performing an intravitreal injection. More than 99 percent use povidone-iodine pre-injection. The majority measure the injection site from the limbus (56 percent) and inject straight into the vitreous cavity (96 percent). Most do not displace the conjunctiva (83 percent). Seventy-two percent routinely assess post-injection optic nerve perfusion, primarily by gross visual acuity measurement (32 percent). While nearly one-third of participants use prophylactic topical antibiotics pre-injection, more than two-thirds use topical antibiotics post-injection. Forty-six percent perform bilateral simultaneous intravitreal injections. The majority of respondents use a 30-ga. needle for the injection of ranibizumab (78 percent) and bevacizumab (60 percent). However, respondents use both a 27- and 30-ga. needle for the injection of triamcinolone acetonide. The authors of the study concluded that further investigation is needed to elucidate best practice patterns.

Am J Ophthalmol 2011;151:329-32
Green-Simms AE, Ekdawi NS, Bakri SJ.

Streptococcus Most Common Isolate Seen in Endophthalmitis
New research suggests that Streptococcus species and gram-negative organisms are the most common causative isolates identified in delayed-onset bleb-associated endophthalmitis. Using a retrospective consecutive case series to report the clinical features, organisms and outcomes of patients with the disease, researchers evaluated cases of patients who were treated for delayed-onset bleb-associated endophthalmitis in a single institution between January 1996 and July 2008. Information on visual acuities, clinical characteristics, causative organisms and treatment outcomes were collected. Infections within one month of glaucoma filtering surgery, inadvertent filtering blebs after cataract surgery and patients with glaucoma drainage devices were excluded.

During the case series, a total of 71 eyes from 68 patients were identified. An adjunctive antifibrotic agent was used in 48 eyes (68 percent). The mean time between surgery and endophthalmitis was 4.8 years (range, 0.1 to 16; standard deviation, 3.6). The average follow-up time after initial treatment was 37 months (range one to 144; SD, 41). At presentation, 17 eyes (24 percent) had a bleb leak. Fifty-seven eyes (83 percent) were culture-positive. The most common causative organisms were Streptococcus species in 20 eyes (30 percent), gram-negative organisms in 19 eyes (28 percent) and coagulase-negative Staphylococcus in 12 eyes (18 percent). All gram-positive isolates were sensitive to vancomycin. Nine eyes (13 percent) eventually underwent evisceration or enucleation secondary to pain and/or poor vision. The main outcome measure was best-corrected visual acuity at the last follow-up examination. Final visual acuities in the initial tap/inject group (n=45) versus the initial vitrectomy group (n=24) were as follows: ≥20/40 (29 percent vs. 4.2 percent), 20/50 to 20/400 (36 percent vs. 29 percent) and <5/200 (36 percent vs. 62 percent).

Retina 2011;31:344-52
Leng T, Miller D, Flynn HW Jr, et al.