Panos G. Christakis

Original articleThe Ahmed Versus Baerveldt Study: One-Year Treatment Outcomes

OBJECTIVE To report the 1-year treatment outcomes of the Ahmed Versus Baerveldt (AVB) Study. DESIGN Multicenter randomized clinical trial. PARTICIPANTS A total of 238 patients were enrolled in the study, including 124 in the Ahmed group and 114 in the Baerveldt group. METHODS Patients aged 18 years or older with uncontrolled glaucoma refractory to medicinal, laser, and surgical therapy were randomized to undergo implantation of an Ahmed-FP7 valve (New World Medical, Inc., Rancho Cucamonga, CA) or a Baerveldt-350 implant (Abbott Medical Optics, Inc., Santa Ana, CA), to be followed for 5 years. MAIN OUTCOME MEASURES The primary outcome measure was failure, defined as intraocular pressure (IOP) out of target range (5-18 mmHg with ≥ 20% reduction from baseline) for 2 consecutive visits after 3 months, vision-threatening complications, additional glaucoma procedures, or loss of light perception. Secondary outcome measures included IOP, medication use, visual acuity, complications, and interventions. RESULTS There were no significant differences in baseline ocular or demographic characteristics between the study groups with the exception of sex. Preoperatively, the study group had a mean IOP of 31.4 ± 10.8 mmHg on a mean of 3.1 ± 1.0 glaucoma medications with a median Snellen acuity of 20/100. The cumulative probability of failure a 1-year was 43% in the Ahmed group and 28% in the Baerveldt group (P = 0.02). The mean IOP at 1 year was 16.5 ± 5.3 mmHg in the Ahmed group and 13.6 ± 4.8 mmHg in the Baerveldt group (P < 0.001). The mean number of glaucoma medications required was 1.6 ± 1.3 in the Ahmed group and 1.2 ± 1.3 in the Baerveldt group (P = 0.03). Visual acuity was similar in both groups at all visits in the first year (P = 0.66). In the first year after surgery, there were a similar number of patients who experienced postoperative complications in the 2 groups (45% Ahmed, 54% Baerveldt, P = 0.19), but a greater number of patients in the Baerveldt group required interventions (26% Ahmed vs. 42% Baerveldt, P = 0.009). CONCLUSIONS The Baerveldt-350 group had a higher success rate than the Ahmed-FP7 group after 1 year of follow-up, but required a greater number of interventions. FINANCIAL DISCLOSURE(S) Proprietary or commercial disclosure may be found after the references.

The Ahmed Versus Baerveldt Study: Design, Baseline Patient Characteristics, and Intraoperative Complications

OBJECTIVE To report the design, baseline patient characteristics, and intraoperative complications of the Ahmed Versus Baerveldt (AVB) Study. DESIGN Multicenter, randomized, clinical trial. PARTICIPANTS Patients were recruited from 7 international clinical sites and treated by 10 surgeons between 2005 and 2009. Inclusion criteria required that patients be at least 18 years of age and have uncontrolled glaucoma refractory to medicinal, laser, and surgical therapy. METHODS Eligible patients were randomized to undergo implantation of an Ahmed-FP7 valve (New World Medical, Inc., Rancho Cucamonga, CA) or a Baerveldt-350 implant (Abbott Medical Optics, Inc., Santa Ana, CA) using standardized surgical technique, to be followed for 5 years. MAIN OUTCOME MEASURES The primary outcome measure was failure, defined as intraocular pressure (IOP) out of target range (5-18 mmHg with ≥ 20% reduction from baseline) for 2 consecutive visits after 3 months, vision-threatening complications, additional glaucoma procedures, or loss of light perception. Secondary outcome measures included IOP, medication use, visual acuity, complications, and interventions. RESULTS A total of 238 patients were enrolled in the study; 124 received the Ahmed-FP7 valve implant and 114 received the Baerveldt-350 implant. The 2 treatment groups did not differ in any baseline characteristics with the exception of sex. The mean age of the study group was 66 ± 16 years, and 55% were women, with a greater proportion in the Baerveldt group (P=0.01). The mean baseline IOP of the study group was 31.4 ± 10.8 on a mean of 3.1 ± 1.0 glaucoma medications. The median Snellen visual acuity was 20/100, mean number of previous laser therapies was 0.9 ± 1.1, and mean number of previous surgeries was 1.7 ± 1.2. Five (4%) patients in the Ahmed group and 4 (4%) patients in the Baerveldt group experienced significant intraoperative complications. CONCLUSIONS Aqueous drainage devices are being increasingly used for glaucoma refractory to conventional treatment, and the AVB Study compares the 2 most commonly implanted devices. The 2 groups had similar baseline characteristics, and there were a similar number of intraoperative complications for both devices. FINANCIAL DISCLOSURE(S) Proprietary or commercial disclosure may be found after the references.

Progressive multifocal leukoencephalopathy in an immunocompetent patient

A 69-year old man presents with a subacute history of worsening confusion, anxiety and abnormal gait. Brain MRI revealed an extensive non-enhancing signal abnormality of parieto-occipito-temporal white matter. CSF PCR was positive for JC virus, suggestive of progressive multifocal leukoencephalopathy (PML). Extensive workup for occult immunosuppression was negative. Although PML in an immunocompetent patient is exceedingly rare, biopsy confirmed the diagnosis. Mirtazapine and mefloquine therapies were initiated and JCV DNA titre decreased by 100-fold at six months. One year later, his clinical course had stabilized and neuroimaging was improved. Our case suggests that PML can rarely afflict immunocompetent individuals and that serotonin receptor targeting pharmacological therapy may improve the outcome.

Idiopathic hypertrophic pachymeningitis mimicking neurosarcoidosis.

The approach to a patient presenting with multiple cranial europathies is complex given the diverse number of causes includng neoplastic, vascular, traumatic, infectious, autoimmune and nflammatory etiologies. In cases where imaging reveals thickened ura with enhancement around multiple cranial nerves and no priary cause can be found, the diagnosis of idiopathic hypertrophic achymeningitis (IHP) is given [1–3]. Here we present the case of a atient with multiple worsening cranial neuropathies who underent extensive evaluation consistent with neurosarcoidosis, but hose dural biopsy revealed IHP.

Referral characteristics and wait times for uveitis consultation at academic tertiary care centres in Toronto

OBJECTIVE To assess the characteristics of referrals to academic uveitis tertiary care centres in Toronto and identify determinants of wait time for consultation. DESIGN Retrospective case series. METHODS Consecutive new uveitis referrals received at 5 University of Toronto-affiliated uveitis tertiary care centres, between February 2016 and November 2016, were included. RESULTS A total of 159 new uveitis referrals were received from academic (69%) and community (31%) providers. A large proportion of referrals were sent by comprehensive ophthalmologists (33%) and retina specialists (38%). Disease was bilateral in 46% of cases, had an acute onset in 43% of cases, and was classified as posterior uveitis in 38% of cases. Disease etiology at the time of referral was unknown in 55% of cases. Only 43% of all referrals included a basic uveitis workup, and patients who had undergone diagnostic testing had a shorter wait time for consultation (41 ± 43 vs. 59 ± 54 days, p = 0.033). Acute uveitis had a shorter wait time compared with recurrent and chronic uveitis (33 ± 42 vs. 66 ± 44 and 59 ± 58 days, p < 0.001). Referrals triaged as urgent had significantly shorter wait times compared with referrals triaged as semiurgent or elective (7 ± 10 vs. 54 ± 43 and 88 ± 59, p < 0.001). CONCLUSIONS Referrals to academic uveitis tertiary care centres in Toronto are often acute, bilateral cases affecting the posterior segment without a known etiology. Approximately half of referrals include no diagnostic workup, which may delay diagnosis for patients and lengthen wait times for consultation. We provide a set of recommendations for investigations that should be included in uveitis referrals.

The Ahmed Versus Baerveldt (AVB) Study

G laucoma drainage devices are being increasingly used in the treatment of advanced glaucoma refractory to medical therapy or in cases that have failed trabeculectomy with antimetabolite. The Ahmed Versus Baerveldt (AVB) Study is an international, multicenter, randomized clinical trial comparing the two most frequently used devices. Five-year results have been recently published providing high quality evidence to guide a surgeon’s decision on which device to use.

Comparison of the Ahmed and Baerveldt glaucoma shunts with combined cataract extraction

OBJECTIVE To compare the surgical outcomes of combined phacoemulsification with either Ahmed glaucoma valve (AGV) or Baerveldt glaucoma implant (BGI). DESIGN Retrospective cohort study. PARTICIPANTS A total of 104 eyes that underwent combined phacoemulsification with either AGV (PhacoAGV; n = 57) or BGI (PhacoBGI; n = 47) implantation. METHODS Failure was defined as uncontrolled intraocular pressure (IOP; <5 mm Hg, ≥18 mm Hg, or <20% reduction), additional glaucoma surgery, vision-threatening complications, or progression to no-light-perception vision. RESULTS The PhacoAGV group was older (p = 0.03), had poorer baseline visual acuity (VA; p = 0.001), and had fewer previous glaucoma surgeries (p = 0.04). Both groups had similar baseline IOP (PhacoAGV: 26.4 ± 8.3 mm Hg; PhacoBGI: 25.7 ± 7.3; p = 0.66) and glaucoma medications (PhacoAGV: 3.8 ± 1.0; PhacoBGI: 3.6 ± 1.5; p = 0.54). At 2 years, failure rates were 44% in the PhacoAGV group and 23% in the PhacoBGI group (p = 0.02). Both groups had similar mean IOP reduction (PhacoAGV: 45%; PhacoBGI: 47%, p = 0.67) and medication use reduction (PhacoAGV: 47%; PhacoBGI: 58%, p = 0.38). The PhacoBGI group had higher IOP and medication use up to 1 month (p < 0.05). Both groups improved in VA from baseline (p < 0.05) and had similar overall complication rates (p = 0.31). The PhacoBGI group required more overall interventions (p < 0.0005). CONCLUSIONS This comparative study found no difference in IOP, glaucoma medications, or complication rates between PhacoAGV and PhacoBGI at 2 years, despite BGIs being implanted in patients at higher risk for failure. The PhacoAGV group had higher failure rates at 2 years. Both groups had significant improvements in VA due to removal of their cataracts. The PhacoBGI group required more interventions, but most of these were minor slit-lamp procedures.

Medical students' attitudes on diversity when applying to Toronto's ophthalmology residency program

BACKGROUND Affirmative action is a controversial admissions policy practised by universities in the United States and other countries around the world. It is currently not used at the University of Toronto ophthalmology residency program. A survey was conducted to determine the opinions of applicants as to the role that affirmative action and quotas should play during the admissions process and to determine the current ethnic breakdown of the applicants to ophthalmology. METHODS A survey of 14 questions was sent out to all 72 medical students applying for a residency position in our program. The response rate was 58%. The students were asked to agree or disagree on a 5-point Likert scale with statements related to ethnicity, gender, and whether affirmative action policies exist or should exist for certain groups. RESULTS The majority of the respondents (26/42, 62%) considered themselves an ethnic minority, and 57% (24/42) considered themselves a visible minority. Most (32/42) felt that the sex of the applicant should not play a role in the selection process. Only 24% (10/42) supported affirmative action, and only 12% (5/42) supported quotas for minority applicants. INTERPRETATION The majority of survey respondents in this study did not support affirmative action or quotas at the University of Toronto ophthalmology program. The applicants to this program represent a diverse group of individuals from a multitude of ethnic, cultural, and racial backgrounds, and, in their average opinion, affirmative action policies would not benefit our admissions program.