Microscope-Integrated OCT During Ophthalmic Surgery
October JAMA Ophthalmology
Ehlers et al. assessed the feasibility and effect on surgical decision making of a microscope-integrated intraoperative OCT (iOCT) system. Their report highlights the 1-year results (March 2014-Feb. 2015) from the Rescan 700 (Carl Zeiss Meditec) portion of a single-site, multisurgeon, prospective consecutive case series study known as DISCOVER (Determination of Feasibility of Intraoperative Spectral Domain Microscope Combined/Integrated OCT Visualization During En Face Retinal and Ophthalmic Surgery).
Data on clinical characteristics of patients undergoing ophthalmic surgery were collected, and iOCT was performed at surgical milestones, as directed by the operating surgeon. A questionnaire was issued to each surgeon and completed after each case to evaluate the role of iOCT during surgery. The main outcomes were the percentage of cases with successful image acquisition with iOCT (i.e., its feasibility) and the percentage of cases in which iOCT altered surgical decision making (i.e., its utility).
During year 1 of the DISCOVER study, a total of 227 eyes (91 anterior segment cases and 136 posterior segment cases) underwent imaging with the Rescan 700 system. Successful imaging—that is, the ability to acquire an OCT image of the tissue of interest—was obtained for 224 of 227 eyes (99%). With regard to utility, the iOCT data altered the surgeon’s decision making in 38% of lamellar keratoplasty cases (e.g., showing complete graft apposition when the surgeon believed there was interface fluid). In membrane-peeling procedures, iOCT information was discordant with the surgeon’s impression of completeness of peel in 19% of cases (e.g., lack of residual membrane or presence of occult membrane), which affected surgical maneuvers.
The authors concluded that this study demonstrates the feasibility of real-time iOCT with a microscope-integrated system for use in ophthalmic surgery. The information gained from iOCT appears to allow surgeons to assess subtle details in a unique perspective from standard en face visualization. Although the use of this device affected surgical decision making in some cases, the impact of these changed decisions on outcomes remains unknown. A randomized masked trial would be valuable in confirming these results.
Compounded Bevacizumab and Postinjection Endophthalmitis
October JAMA Ophthalmology
Current draft guidelines set forth by the U.S. FDA for compounded or repackaged medications could greatly limit the use of bevacizumab by ophthalmologists. However, apart from highly publicized case reports, there is little evidence on the need for additional regulations. VanderBeek et al. sought to determine whether bevacizumab distributed through compounding pharmacies increases the risk for endophthalmitis compared with ranibizumab in single-use vials from the manufacturer.
This retrospective cohort study used medical claims data that were submitted to a large national U.S. insurer from ambulatory care centers across the United States. Information was available from 530,382 intravitreal injections administered from Jan. 1, 2005, through Dec. 31, 2012. Individuals from this data set who received at least 1 intravitreal injection of bevacizumab or ranibizumab and had at least 6 months of data before and 1 month after the injection were eligible. Patients were excluded for any previous diagnosis of endophthalmitis, multiple injected drugs on the index day, or intraocular surgery within 15 days of the injection or between the injection and a diagnosis of endophthalmitis. The main outcome was the odds of developing endophthalmitis after an intravitreal injection of bevacizumab compared with ranibizumab.
After exclusions, there were 296,565 injections of bevacizumab (51,116 patients) and 87,245 injections of ranibizumab (7,496 patients). The authors found 71 cases of endophthalmitis (49 in the bevacizumab cohort and 22 in the ranibizumab cohort) for an endophthalmitis rate of 0.017% (1 case per 6,061 injections) for bevacizumab and 0.025% (1 case per 3,968 injections) for ranibizumab. After controlling for age, race, sex, injection-related diagnosis, and year of injection, the authors found no significant association with development of endophthalmitis after bevacizumab injection compared with ranibizumab (odds ratio, 0.66; 95% CI, 0.39-1.09; p = .11).
The results suggest that bevacizumab, as currently administered via intravitreal injection in the United States, does not increase the risk for endophthalmitis; thus, additional regulations on the use of repackaged bevacizumab with respect to endophthalmitis may be unnecessary.
Body Levels of Trace Metals and Glaucoma Prevalence
October JAMA Ophthalmology
Abnormal body levels of essential elements and exposure to toxic trace metals have been postulated to contribute to the pathogenesis of diseases affecting many organ systems. Lin et al. investigated possible associations between trace metals and the prevalence of glaucoma in a cross-sectional population-based study in South Korea.
Blood or urine metallic element levels and information pertaining to ocular disease were available for 2,680 individuals 19 years and older participating in the fourth Korea National Health and Nutrition Examination Survey between Jan. 1, 2008, and Dec. 31, 2009.
Glaucoma diagnosis was based on criteria established by the International Society of Geographic and Epidemiologic Ophthalmology. Demographic, comorbidity, and health-related behavior information was obtained through interviews. Multivariable logistic regression analyses were performed to determine associations between blood and urine trace element levels and the odds of glaucoma diagnosis. The main outcome was the presence or absence of glaucoma.
After adjustment for potential confounders, blood manganese level was negatively associated with the odds of glaucoma diagnosis (odds ratio [OR], 0.44). Blood mercury level was positively associated with glaucoma prevalence (OR, 1.01). No definitive association was identified between blood cadmium or lead levels or urine arsenic level and a diagnosis of glaucoma. Although these findings suggest that a lower blood manganese level and a higher blood mercury level are associated with greater odds of glaucoma, prospective studies are needed to confirm the role of trace minerals in development of glaucoma.
JAMA Ophthalmology summaries are based on authors’ abstracts, as edited by senior editor(s).
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