Sourabh Arora

Northern Alberta remote teleglaucoma program: clinical outcomes and patient disposition.

OBJECTIVE To review the diagnostic outcomes and clinical referral pathways of patients assessed and managed through a collaborative care patient-centred teleglaucoma program. STUDY DESIGN Retrospective cohort study. METHODS Eligible patients were those assessed by the referring optometrist or ophthalmologist to be open-angle glaucoma suspects or to have definite early open-angle glaucoma. A glaucoma specialist graded each case through virtual consultation. Clinical referral pathways were noted: in-person consultation with glaucoma specialist, repeat teleconsultation, collaborative glaucoma management with optometrist, or referral for nonglaucomatous ophthalmic pathology. RESULTS A total of 247 patients were referred to the program from 2008 to 2012. Of all teleconsults, 31.1% were diagnosed with glaucoma, 42.1% were suspects, and 26.7% were unaffected. Of all patients, 27% were referred for in-person glaucoma evaluation; 69% of patients could be managed by their referring optometrist, with 48% of patients requiring repeat teleconsultation. Treatment was initiated before being seen for 87% of patients with definite glaucoma and 28% of glaucoma suspects. CONCLUSIONS Of all patients seen through the remote teleglaucoma program, most did not require an in-person consultation with an ophthalmologist and could be managed through distance collaboration. For the approximately one third who were diagnosed with glaucoma based on virtual assessment, medication was started in the majority of cases and in-person consultation was arranged. Further studies to validate and consider cost-effectiveness of this system are under way.

Implantation of 2 trabecular microbypass stents in a patient with primary open-angle glaucoma refractory to previous glaucoma-filtering surgeries

UNLABELLED A 77-year-old woman with primary open-angle glaucoma was referred for surgical evaluation after failing to achieve target intraocular pressure (IOP) despite previous combined phacotrabeculectomy and Ahmed valve implantations. The IOP prior to surgery was 28 mm Hg on topical dorzolamide-timolol, latanoprost, and brimonidine. Trabecular bypass surgery with implantation of 2 iStents was performed. The IOP decreased by 11 mm Hg to 17 mm Hg after surgery and has remained stable for 2 years. This is the first published case reporting this magnitude of IOP reduction sustained for more than 2 years following insertion of 2 trabecular microbypass stents in a patient who had previous glaucoma-filtering surgeries. Further prospective studies are needed to establish expanded surgical indications for implantation of trabecular microbypass stents. FINANCIAL DISCLOSURE No author has a financial or proprietary interest in any material or method mentioned.

Phaco-trabectome versus phaco-iStent in patients with open-angle glaucoma

OBJECTIVE To investigate efficacy and safety of phaco-trabectome (PT) versus phaco-iStent (Pi) for intraocular pressure (IOP) control in open-angle glaucoma (OAG). DESIGN Retrospective comparative case series. PARTICIPANTS A total of 70 eyes of 55 patients with OAG underwent either PT surgery by a single surgeon or Pi (insertion of 2 stents) by another surgeon in Canada between January 2010 and December 2012. METHODS The medical records of consecutive adult patients who underwent either PT or Pi surgery were reviewed. All patients who satisfied both the inclusion and exclusion criteria were included in the outcomes analyses. IOP reduction, reduction in glaucoma medication, safety profile, and best-corrected visual acuity were evaluated. RESULTS Thirty-six eyes of 30 patients had PT and 34 eyes of 25 patients had Pi. Baseline IOP was higher in the PT group (20.92 ± 5.07 mm Hg) than in the Pi group (17.47 ± 4.87 mm Hg; p = 0.026). At 12 months there was no significant difference between groups in relative reduction of mean IOP (PT -5.09 ± 5.73, 24% relative reduction vs. Pi -3.84 ± 3.80, 22% relative reduction; p = 0.331) or glaucoma medication use (PT -0.49 ± 1.17 vs. Pi -0.26 ± 0.73; p = 0.168) from baseline. However, Pi had significantly fewer individual complications (PT 20 vs. Pi 5; p < 0.0001) throughout the postoperative period. CONCLUSION At 12 months of follow-up, both techniques significantly lowered IOP, but fewer complications were observed in the Pi group.

Tonometer tip disinfection: principles, evidence, and importance of end-user engagement in policy formulation

Contact Goldmann applanation tonometry (GAT) is a gold standard component of the eye examination. The best current evidence reveals that clinical incidence of infections transmitted by tonometers is low and is limited to less invasive microorganisms. Laboratory studies of more invasive microorganisms suggest a risk for transmission that is not supported by clinical evidence. Disinfection protocols and medical device classification should also consider the basic principles of ocular surface tissue and the tear film. In light of the aforementioned, current manufacturer recommendations suggest a protocol that, in our opinion, is not evidence or best practice based, and poses an inordinate increase in financial and human resource costs. We suggest ophthalmologists engage proactively in dialogue and policy formulation on this issue so that thoughtful, pragmatic options for disinfection can be developed. Several provinces have or are developing protocols around tonometer tip disinfection, and this is, therefore, an opportune time to consider best practices and thinking in this area. Not surprisingly, tonometer disinfection practices and guidelines vary widely and, in the absence of solid evidence to support any single technique, there appears to be no agreement on a method that adequately ensures patient safety, whereas taking into account another fundamental consideration: optimal use of finite resources. It is hoped that that this editorial will initiate an open dialogue that actively engages users themselves to devise practical and cost-effective disinfection protocol options. Measuring intraocular pressure (IOP) is supported by the Canadian Ophthalmological Society clinical guidelines as a gold standard element of the eye examination. Monitoring precise changes in IOP is of the utmost importance, particularly in diagnosing and managing patients with glaucoma where each millimeter of mercury can make a difference to the health of the optic nerve, visual field, or both. Research supports GAT as the most precise and reliable method of measuring IOP. Other methods, including disposable prisms, are not considered on par, because they may not be as accurate and typically have more variability associated with them, especially at very low or high pressures. In addition, it has been reported that use of disposable tips does not completely prevent bacterial or viral infection as staff admit to touching the face of the prism. There have been reports of infectious keratoconjunctivitis (primarily involving adenovirus) being transmitted from ocular equipment, such as GAT prisms, to patients

Porcine cataract creation using formalin or microwave treatment for an ophthalmology wet lab

OBJECTIVE Wet labs are an important part of ophthalmology residency training in order to develop intraocular surgical proficiency. The purpose of this study was to compare the effectiveness of formalin versus microwave treatment to produce porcine cadaveric cataracts. DESIGN This study was a comparative observational study at a single centre. METHODS Cataracts were created through the injection of 0.1 mL of 100% ethanol into the anterior chamber followed by the infiltration of 0.1 mL of 37% formalin using a short 30-gauge needle into the lens by introduction through the pars plana. The comparison group investigated porcine eyes treated with a microwave for 5-13 seconds using a 700 W power setting. Two observers used a validated nuclear opalescence and corneal clarity scale to independently grade the treated eyes. RESULTS In total, 70 eyes were treated with either formalin or by microwave. The formalin eyes had an average lens opacity score of 0.04 ± 0.03 and 1.91 ± 01.10 pre- and post-treatment (p < 0.001). Microwaved eyes had an average pretreatment lens opacity of score 0.10 ± 0.31, which increased to 2.86 ± 0.1.08 post-treatment (p < 0.001). Post-treatment lens opacity was significantly greater in microwave eyes than in formalin-treated eyes (p = 0.003). Pretreatment corneal clarity was 3.65 ± 0.73 in the formalin group, and 3.70 ± 0.93 in the microwave group. After treatment, there was a significant reduction in corneal clarity within the formalin (3.01 ± 1.04, p = 0.0012) and microwave groups (3.03 ± 1.07, p < 0.001). CONCLUSIONS Porcine eye models provide a realistic way to simulate cataracts and so residents can practice the basics of cataract surgery. Both microwave and formalin-based treatments are able to opacify the porcine lens with acceptable reductions in corneal clarity.

Association of pseudoexfoliation syndrome with cardiovascular and cerebrovascular disease: a systematic review and meta-analysis

OBJECTIVE Pseudoexfoliation syndrome (PEX) is a systemic disease, but evidence of its association with cardiovascular disease (CVD) and cerebrovascular disease (CVA) is controversial. A quantitative systematic review will provide an accurate summary of the current body of the literature. DESIGN Meta-analysis. PARTICIPANTS Not applicable. METHODS A comprehensive literature search of published and unpublished English-language studies was performed. Summary statistics were calculated using inverse variance weighting and are presented in forest plots. Sources of variance were evaluated statistically. RESULTS After screening 4547 studies, 47 articles were reviewed, and 25 eligible studies were selected that reported patients from around the world. Twenty studies enrolling 9583 individuals with PEX evaluated CVD, providing a summary odds ratio (OR) of 1.61 (95% CI 1.37-1.90). Eleven studies, enrolling 1308 PEX patients, evaluated CVA and generated a summary OR of 1.76 (1.40-2.22). For any vascular event (AVE) using all 25 studies, there were 9716 PEX patients and 363,312 control patients, yielding a summary OR of 1.64 (95% CI 1.39-1.92). Analysis for publication bias with the Eggers test was not significant for studies reporting CVD and AVE (p = 0.92 and 0.64, respectively) but was significant for CVA (p = 0.03). Asymmetry of Beggs funnel plot was noted for the CVA and AVE analyses. Multiple sensitivity analyses were performed, including assessment of study quality; the OR for all 3 outcomes varied minimally and remained significant in all analyses. CONCLUSION There is strong evidence that PEX is significantly associated with both CVD and CVA.

Compressed 3D and 2D digital images versus standard 3D slide film for the evaluation of glaucomatous optic nerve features

Synopsis Clinicians can feel confident compressed three-dimensional digital (3DD) and two-dimensional digital (2DD) imaging evaluating important features of glaucomatous disc damage is comparable to the previous gold standard of stereoscopic slide film photography, supporting the use of digital imaging for teleglaucoma applications. Background/aims To compare the sensitivity and specificity of 3DD and 2DD photography with stereo slide film in detecting glaucomatous optic nerve head features. Methods This prospective, multireader validation study imaged and compressed glaucomatous, suspicious or normal optic nerves using a ratio of 16:1 into 3DD and 2DD (1024×1280 pixels) and compared both to stereo slide film. The primary outcome was vertical cup-to-disc ratio (VCDR) and secondary outcomes, including disc haemorrhage and notching, were also evaluated. Each format was graded randomly by four glaucoma specialists. A protocol was implemented for harmonising data including consensus-based interpretation as needed. Results There were 192 eyes imaged with each format. The mean VCDR for slide, 3DD and 2DD was 0.59±0.20, 0.60±0.18 and 0.62±0.17, respectively. The agreement of VCDR for 3DD versus film was κ=0.781 and for 2DD versus film was κ=0.69. Sensitivity (95.2%), specificity (95.2%) and area under the curve (AUC; 0.953) of 3DD imaging to detect notching were better (p=0.03) than for 2DD (90.5%; 88.6%; AUC=0.895). Similarly, sensitivity (77.8%), specificity (98.9%) and AUC (0.883) of 3DD to detect disc haemorrhage were better (p=0.049) than for 2DD (44.4%; 99.5%; AUC=0.72). There was no difference between 3DD and 2DD imaging in detecting disc tilt (p=0.7), peripapillary atrophy (p=0.16), grey crescent (p=0.1) or pallor (p=0.43), although 3D detected sloping better (p=0.013). Conclusions Both 3DD and 2DD imaging demonstrates excellent reproducibility in comparison to stereo slide film with experts evaluating VCDR, notching and disc haemorrhage. 3DD in this study was slightly more accurate than 2DD for evaluating disc haemorrhage, notching and sloping.

Optic Disk Size Assessment Techniques: Photo Essay

Measuring optic disc size is an essential part of the optic nerve head for evaluation for glaucoma. Large discs that appearing to have large cups may in fact be physiologic because of normal neuroretinal rim area. Small discs may appear to have a normal cup to disc ratio, but have decreased neuroretinal rim area in association with glaucoma. We illustrate relevance of these points with respect to glaucoma diagnosis in two case examples. We then present clinically relevant techniques to assess disc size including direct ophthalmoscopy, slit lamp biomicroscopy, disc macula: disc diameter ratio, planimetric assessment of fundus photographs, and imaging modalities such as OCT as well as HRT.

Phenotypic features of Chinese family members with primary angle closure.

OBJECTIVE To describe ocular phenotypic features in Chinese families with primary angle closure (PAC). DESIGN Prospective cohort study. PARTICIPANTS 428 individuals of 103 eligible families. METHODS Probands identified in clinic and their relatives were examined. Measurements included intraocular pressure, anterior chamber depth, lens thickness, axial length, and gonioscopic features related to the anterior chamber angle. Electroretinogram (ERG) testing for dark and light adaptation on both eyes of each individual examined was also obtained. RESULTS There were 144 PAC affected patients (33.7%), 60 suspects (14%), and 224 unaffected individuals (52.3%). There were more than 2 affected members in 51 families (49.5%). Compared with unaffected individuals, affected individuals were more likely to be female, have shallower peripheral and central anterior chamber depths, narrower angles, thicker lenses, and shorter axial lengths (p<0.001). Affected patients and suspects had similar axial lengths (p>0.05). Compared with unaffected individuals, affected and suspect individuals showed ERG adaptation abnormalities (p<0.05). Of 45 unaffected individuals with mean axial length ≤ 22.00 mm (10.51%), 20 individuals (4.67%) showed ERG adaptation abnormalities similar to affected patients and suspects (p> 0.05). CONCLUSIONS Patients with PAC were significantly more likely to be female, have shorter axial length, and have thicker lenses compared with unaffected individuals. PAC suspects showed similar axial lengths to affected individuals. ERG abnormalities mainly occurred in affected patients and suspects, but also occurred in unaffected individuals with short axial length.