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Persistent Exogenous Bacterial Endophthalmitis
May 2016
Leung et al. performed a consecutive case series to investigate the characteristics and outcomes of persistently vitreous culture–positive bacterial exogenous endophthalmitis. They found that despite antibiotic therapy, visual outcomes were generally poor, with no statistically significant improvement in visual acuity (VA) between the initial and final examinations.
The 36 participants in this series were patients with exogenous endophthalmitis who were treated at the same tertiary care center between 1981 and 2015 and in whom vitreous culture identified the same bacteria on 2 or more visits (most common organisms, gram-positive Staphylococcus and Streptococcus). By comparison, over the same time period at the same institution, there were 1,189 patients with bacterial endophthalmitis who had only 1 positive culture. In the 36 patients with persistently positive cultures, 50% had developed endophthalmitis after cataract surgery, 31% after trabeculectomy, and the rest after other procedures or trauma. On presentation, mean VA was 2.16 ± 0.77 logMAR (Snellen equivalent approximately 20/2,900).
On the day of endophthalmitis diagnosis, all patients received intravitreal vancomycin and adjunctive topical antibiotics, 92% received an added intravitreal antibiotic, and 36% received systemic antibiotics. In 94%, topical steroids were used within 24 hours after initiation of antibiotics. In addition to these medications, 78% of patients had a vitreous tap, while 22% had a pars plana vitrectomy. Patients received further therapy if they were not improving. Ultimately, 92% of patients had a vitrectomy.
After a mean follow-up of 26.5 months, the mean final BCVA was 2.08 ± 0.97 logMAR (Snellen approximately 20/2,400). Of the 36 patients, 33% had a final VA of 20/200 or better, while 31% had no light perception or were enucleated.
The researchers could not identify any statistically significant associations between outcomes and initial vitreous tap vs. vitrectomy, use of steroids, type of bacteria, or timing of second treatment. The only group that experienced significant improvement in VA after treatment was patients with a history of uncomplicated phacoemulsification. Also, patients whose vision was hand motions or better at diagnosis were more likely to recover 20/200 or better vision at the final visit.
Intravitreal Aflibercept and Ranibizumab Injections for PCV
May 2016
In a study conducted in South Korea, Cho et al. compared the effectiveness of intravitreal aflibercept and ranibizumab in patients with polypoidal choroidal vasculopathy (PCV). They found no significant difference between the treatments in visual acuity (VA) results but observed that aflibercept caused more polyp regression.
Participants in this chart review study were 98 patients aged 50 years or older with angiography-confirmed PCV who were treated with either aflibercept or ranibizumab alone. The main outcome measure was mean change in VA at 3, 6, 9, and 12 months; the secondary outcome was mean change in central foveal thickness (CFT) at those same time points. All patients received a loading dose of 1 intravitreal injection of the study drug every month for 3 months; subsequent injections were made on an as-needed basis.
The aflibercept group had a VA improvement from 20/85 (Snellen equivalent) at baseline to 20/55 at 12 months, while the ranibizumab group improved from 20/91 to 20/61 at the same points. In the aflibercept group, CFT was reduced from 396 ± 167 μm at baseline to 212 ± 144 μm at 12 months; in the ranibizumab group, CFT was reduced from 402 ± 198 μm to 240 ± 183 μm. Although the within-group improvements were significant, there was no statistically significant difference between the groups.
The only statistically significant difference between groups was in polyp regression: 39.5% of the aflibercept group experienced polyp regression compared with 21.7% of the ranibizumab group. The reason for this difference is unclear, although the authors said that some experts have posited that it is due to aflibercept’s ability to bind VEGF-B and placental growth factor in addition to VEGF-A, the target for ranibizumab.
What Does Femtosecond Technology Add to Phaco?
May 2016
In an editorial that asks the question “What exactly does femtosecond technology add to phacoemulsification based on objective studies to date?” Olson discusses femtosecond laser–assisted cataract surgery (FLACS) in the context of past ophthalmic innovations.
The author describes acceptance of technological change as coming in waves, which may be “very small and fleeting” (for example, epikeratophakia or hexagonal keratotomy), larger but not enduring (radial keratotomy), or a lasting “tsunami” (phacoemulsification). He noted that, in retrospect, the adoption of phaco did not seem assured when it was introduced; it was initially criticized by some surgeons as having unacceptable complications and took 20 years of improvement and familiarity before the tipping point was reached. In the author’s opinion, the situation of FLACS at this point is similar to that of phaco 5 years after its introduction.
He presents 2 key principles regarding new ophthalmic technologies: (1) It is inherently unfair to compare a well-evolved technology to one that is just emerging and will undergo further improvements; and (2) any new technology brings with it new complications, which need to be recognized and “weighted for incidence and importance” as part of the acceptance process.
After briefly reviewing 14 published studies on FLACS—which reached differing conclusions about its value—the author stated that “the jury is still out” and that many cataract surgeons remain “underwhelmed” by the idea of FLACS supplanting phaco. He encouraged supporters of FLACS to provide more robust evidence that, in conjunction with further technological advancement, could change that point of view.
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American Journal of Ophthalmology summaries are written by Peggy Denny and edited by Richard K. Parrish II, MD.
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