Bernard Hurley

Controlled Release of Bevacizumab Through Nanospheres for Extended Treatment of Age-Related Macular Degeneration

Bevacizumab (Avastin®) has been used by ophthalmologists in many countries as an off-label drug for the treatment of wet age-related macular degeneration (AMD). Due to its short half-life necessitating frequent intravitreal injection, a method for sustained delivery is in need. We demonstrated that bevacizumab could be released in a sustained fashion over 90 days from nano- and microspheres fabricated from poly(DL-lactide-co-glycolide) and poly(ethylene glycol)-b-poly(D,L-lactic acid), respectively. The drug release rate could be adjusted by alteration of the drug/polymer ratio. The use of such nano- and microspheres as bevacizumab delivery vehicles may improve the treatment of wet AMD.

Test characteristics of point-of-care ultrasonography for the diagnosis of acute posterior ocular pathology

OBJECTIVES The objective of this study was to determine the test characteristics of point-of-care ultrasonography (POCUS) for the diagnosis of retinal tear (RT), retinal detachment (RD), posterior vitreous detachment (PVD), and vitreous hemorrhage (VH). DESIGN A prospective observation study on a convenience sample of patients presenting to a tertiary care emergency general ophthalmology clinic was performed. PARTICIPANTS Adult patients with acute flashes/floaters or new visual field defects were included (n = 62). METHODS POCUS was performed by a study sonographer and compared with a retina specialist examination without sonography imaging. Sonographers were masked to clinical information. Follow-up was performed by a 6-week health records review. The primary outcome was the diagnosis of RD/RT, PVD, and VH. Analyses included descriptive statistics and test characteristics. RESULTS A total of 62 patients with a mean age of 60.8 years were enrolled; 62.9% were female. The mean time to scan required was 7.4 minutes. There was no change in diagnosis at 6 weeks. The sensitivities and specificities, respectively, are as follows: any pathology (n = 60) 88.3% (95% CI 86.8%-89.9%) and 50% (95% CI 2.7%-97.3%); RD (n = 6) 100% (95% CI 53.9%-100%) and 67.9% (95% CI 62.9%-67.9%); RD/RT (n = 23) 47.8% (95% CI 30.8%-62.2%) and 82.1% (95% CI 72.0%-90.6%); PVD (n = 47) 80.9% (95% CI 74.7%-88.0%) and 33.3% (95% CI 14.0%-55.7%); and VH (n = 14) 43.0% (95% CI 21.4%-58.0%) and 93.8% (95% CI 87.5%-98.2%). CONCLUSIONS Ocular POCUS detected all RDs but has limited use for the diagnosis of RTs. Patients with suspected acute ocular posterior pathology should be referred to ophthalmology independent of ocular POCUS.

Resurrection of the bell-ringer

The bell-ringer has long been an established examination tool in medical education. Moving from one gross anatomy examination station to the next at the sound of a bell is certainly a familiar memory. At the University of Ottawa Eye Institute, there existed a long-standing tradition of inviting patients with interesting findings to weekly Grand Rounds. The patients would be examined by all attendees, allowing participants to approach the examination as if they were the initial consultant. As our department has grown and technology has advanced, this practice has gradually been replaced by computer-generated slideshows with digital photographs and videos demonstrating clinical findings. The newer format is more convenient for both staff and patients, and certainly saves time. Digital images, however, are static, two-dimensional, and often of low quality. In addition, the opportunity to search for other clinical clues at the slit lamp is lost using this format. Finally, examining the patient directly affords the benefit of working through diagnostic possibilities at one’s own pace, without prematurely being given the solution. Although it would be impractical in our department to resume examining patients at Grand Rounds, the bellringer format continues to be a part of our residency training program. On a biannual basis, patients with rare corneal pathologies volunteer to be examined by our residents. Following their individual examinations, the residents return as a group to each patient, and the attending staff guides them through the findings and diagnostic pearls. This affords the residents the possibility to examine many rare patients as if it were a first-time consultation and to make their own diagnosis. In a short period, residents are able to view many rare conditions that they may otherwise never have seen. As well, similar pathologies (the stromal dystrophies are a good example) can be directly compared during one session. In summary, although the bell-ringer has traditionally been an examination tool, we have also found it to be a valuable clinical teaching model. The bell-ringer session described above offers a unique clinical complement to our didactic sessions in cornea and external disease. Plans for bell-ringers in other subspecialties are currently under development.