Survey of intravitreal injection techniques and treatment protocols among retina specialists in Canada.

OBJECTIVE: To describe intravitreal injection (IVI) techniques and treatment protocols by retina specialists in Canada from August 1, 2012, to October 1, 2012. DESIGN: Cross-sectional survey. PARTICIPANTS: All fellowship-trained retina specialists across Canada, as identified from the Canadian Ophthalmological Society directory and the Canadian Retina and Vitreous Society directory. METHODS: An anonymous 28-question survey was sent to 125 retina specialists across Canada by email. Reminder letters were sent by email, mail, and fax as necessary. RESULTS: A total of 75 (63%) retina specialists responded to the survey. Most IVIs were performed in the office. Most surgeons did not use gloves (61%), sterile draping (91%), or surgical mask (71%). Antisepsis was used on conjunctiva by 100% and on periocular skin by 48%. Nearly all specialists used a sterile lid speculum (91%). Common anaesthetics included topical proparacaine or lidocaine drops (90%), topical lidocaine gel (25%), topical pledget (23%), and subconjunctival lidocaine injections (23%). Most (83%) dilate the pupil before IVI. Prophylactic topical antibiotics were used by 43%; 50% of these were started immediately after IVI. Injection location was estimated by visualization by 45%. A majority (63%) inject inferotemporally. Anterior chamber paracentesis was performed routinely by 5%. Optic nerve perfusion was formally assessed by 48%. The most common treatment protocol for age-related macular degeneration was treat and extend. For both diabetic and retinal vein occlusion-related macular edema, the most common protocol was 3 initial monthly injections with PRN follow-up. CONCLUSIONS: A wide variety of IVI practice patterns exist in terms of aseptic technique, anaesthetics, prophylactic antibiotics, postinjection monitoring, and treatment protocol.

Resistance of ocular flora to gatifloxacin in patients undergoing intravitreal injections.

OBJECTIVE: To compare gatifloxacin resistance in a population of ophthalmology patients who had received intravitreal injections (IVIs) with prophylactic topical gatifloxacin use to resistance in a similar population of patients who had not received IVI. DESIGN: Nested case-control study. PARTICIPANTS: Fifty eyes of 50 patients who received prior IVI were enrolled, as were 50 control eyes. METHODS: Each patient had a conjunctival swab performed on the study eye, which underwent microbial identification and testing for gatifloxacin resistance using the ellipsoid test to determine a minimum inhibitory concentration (MIC) value for each isolate. The primary outcome was susceptibility to gatifloxacin, as measured by the MIC of each isolate. RESULTS: A total of 111 bacterial isolates were obtained from 60 eyes; the remainder was culture negative. There were no significant differences in bacterial species or culture positivity rate between case and control eyes (50% in cases vs. 66% in controls, p = 0.16). The most common organism was coagulase-negative staphylococcus, comprising 64% of all isolates. Resistance to gatifloxacin was observed in 76% of the bacterial isolates and 38% of patients in the case group, as compared with 3% of bacterial isolates and 4% of patients in the control group, a result that was statistically significant (p = 0.0002 and 0.0008, respectively). The mean gatifloxacin MIC was also significantly higher in the case group. CONCLUSIONS: Topical gatifloxacin prophylaxis in those who receive IVI is associated with an increased rate of gatifloxacin resistance among conjunctival isolates.

Using patient positioning to promote resorption of subretinal fluid in rhegmatogenous retinal detachment before pneumatic retinopexy.

PURPOSE: The purpose of this study was to determine if the volume of subretinal fluid in patients with acute rhegmatogenous retinal detachment may be reduced through patient positioning before pneumatic retinopexy. METHODS: This was a prospective, masked nonrandomized cohort study examining the change in subretinal fluid volume in patients with rhegmatogenous retinal detachment before and after a 1-hour period of specific head positioning, as measured using B-scan ultrasonography. A series of B-scans, each 2 mm apart in the sagittal plane, were acquired for each eye both before and after the positioning period with the patient lying in a supine position. RESULTS: Ten patients with acute unilateral rhegmatogenous retinal detachment were enrolled. All patients experienced a reduction in subretinal fluid volume, from a mean prepositioning volume of 0.89 ± 0.63 mL to a mean postpositioning volume of 0.45 ± 0.43 mL. The mean relative reduction in subretinal fluid measured as a percentage of prepositioning subretinal fluid volume was 55.4% ± 20%, ranging from 35.3% to 93.5%. CONCLUSION: In patients with acute rhegmatogenous retinal detachment that fall within the classic indications for pneumatic retinopexy, significant reduction of subretinal fluid volume may be obtained through a 1-hour period of patient positioning in a retinal break-dependent manner.

Ranibizumab for idiopathic epiretinal membranes: A retrospective case series.

PURPOSE: To study the effect of intravitreal ranibizumab on idiopathic epiretinal membranes (ERMs). METHODS: A retrospective cohort study on a consecutive series of ranibizumab intravitreal injections for epiretinal membranes was performed. Four cases were identified by reviewing a claims database linked to electronic medical records. All patients received a total of three 0.05 mg/0.05 ml ranibizumab intravitreal injections at a monthly interval. The primary outcome measure was the final best-corrected visual acuity (BCVA) at the end of the injection series, and the final central macular thickness (CMT). RESULTS: All four patients completed 3 months follow-up after the last ranibizumab injection. The mean baseline CMT was 509 microns (SD = 111). A trend was noticed for reduction in CMT (Δ = 41 microns) P = 0.08. Three patients improved by one line in their BCVA. The remaining patient maintained the same BCVA. No complications were noted. CONCLUSION: In this study, intravitreal injection of ranibizumab marginally reduced retinal thickness in four patients with minimal improvement in visual acuity. No safety concerns were noticed. Further basic science and clinical studies may be warranted to assess the role of vascular endothelial growth factor and the effect of ranibizumab on idiopathic epiretinal membranes.

Peripapillary choroidal neovascular membrane in a teenage boy: presenting feature of idiopathic intracranial hypertension and resolution with intravitreal bevacizumab.

Peripapillary choroidal neovascular membrane (ppCNVM) is an infrequent finding in patients with idiopathic intracranial hypertension (IIH). In the pediatric subgroup there is only a single previously reported case. We describe the use of intravitreal bevacizumab for ppCNVM in a teenage boy with IIH.

10-Year Framingham risk in patients with retinal vein occlusion: a systematic review and meta-analysis.

OBJECTIVE: Cardiovascular risk factors predispose individuals to retinal vein occlusions (RVOs). Yet, the future risk for development of cardiovascular disease in persons with RVOs is uncertain. We performed a literature review and meta-analysis of studies to determine the 10-year Framingham risk for individuals with RVO. METHODS: A literature search was performed in MEDLINE and EMBASE. Studies were eligible if they included subjects with RVO and presented data on age, sex, smoking status, systolic blood pressure, total cholesterol, and high-density lipoprotein. The 10-year Framingham risk was calculated. Sensitivity analysis was performed and hypothesis testing was carried out using the upper tail z test with α = 0.05 to compare the estimated Framingham risk in RVO patients with the risk in the general Canadian population. Subgroup meta-analysis was carried out by Cochrane Collaboration Review Manager 4.5 software (Cochrane IMS, Copenhagen, Denmark). RESULTS: A final list of 6 articles was included. The estimated 10-year Framingham risk score in subjects with RVO was 10.1% (95% CI 9.9-10.2). Sensitivity analysis found Framingham risk score to be greatest in male smokers. The Framingham risk in subjects with RVO was significantly greater than the general Canadian population. In a subgroup analysis, the 10-year risk was significantly greater in subjects with RVO compared with control subjects. CONCLUSIONS: Patients with RVO have an increased 10-year risk for cardiovascular disease. This risk is greatest for male smokers (high risk). These patients may benefit from therapy aimed at controlling their risk factors. All individuals with an increased Framingham risk should be warned about vision loss as a potential complication of systemic atherosclerotic disease.

Anatomical and visual outcomes of macular hole surgery with short-duration 3-day face-down positioning.

PURPOSE: The role of face-down posturing after macular hole (MH) surgery remains unclear and controversial. We evaluated the anatomical and visual outcomes of MH repair using a short duration (3 days) of prone positioning. METHODS: Prospective series of 50 consecutive eyes in 50 patients with Stage 2 or Stage 3 idiopathic MHs. All eyes underwent vitrectomy MH surgery with internal limiting membrane peeling and 20% sulfur hexafluoride (SF6) gas tamponade. The procedure was combined with phacoemulsification cataract surgery in phakic eyes. Surgical outcomes, MH closure rates, complications, and postoperative visual acuity were investigated. RESULTS: Anatomical closure of MHs was achieved in 49 (98%) of 50 eyes by 1 surgery. Postoperative logarithm of the minimum angle of resolution visual acuity decreased (i.e., improved) by 0.271 (95% confidence interval, 0.101-0.441 [P = 0.0024]). One complication of intraocular lens pupillary capture and one case of chronic cystoid macular edema were observed. There were no complications attributed to intraocular pressure fluctuations. CONCLUSION: Vitrectomy with internal limiting membrane peeling and gas tamponade with SF6 followed by short-duration 3-day face-down positioning is a successful surgical intervention for Stage 2 and Stage 3 idiopathic MHs. This method possessed minimal complications and offered significant improvement in visual acuity.

Visual function and vision-related quality of life after macular hole surgery with short-duration, 3-day face-down positioning.

OBJECTIVE: To investigate the relationship of vision-related quality of life (VRQOL) and visual function in patients undergoing macular-hole (MH) repair with and without cataract surgery and short-duration, 3-day prone posturing. Previous communications have assessed VRQOL in European and Japanese populations, but this is the first study to investigate VRQOL after MH surgery in a Canadian population. DESIGN: Prospective interventional case series. PARTICIPANTS: We studied 20 consecutive eyes in 19 patients with stage 2 and 3 idiopathic macular holes. Of those, 15 received combined cataract and MH surgery, and 5 received MH repair alone. METHODS: Patients completed the self-administered National Eye Institute 25-item Visual Function Questionnaire before and after surgery. All patients received full ocular examinations pre- and postsurgery. Along with the questionnaire scores, we examined macular-hole closure rates, complications, postoperative visual acuity, and intraocular pressure. RESULTS: Macular-hole closure was achieved in 20 of 20 eyes (100%). Mean postoperative logMAR decreased (i.e., improved) by -0.303 (95% CI, -0.501-- -0.105, p = 0.0047). The Visual Function Questionnaire composite score rose from 82.019 ± 12.612 SD to 88.499 ± 7.963 SD (p = 0.012). Subscale scores, including general vision, near activities, mental health, role difficulties, and dependency were all significantly improved (p < 0.05). No complications or intraocular pressure increases were observed. CONCLUSIONS: Macular-hole surgery followed by short-duration, 3-day face-down positioning significantly improved VRQOL and visual acuity in a group of Canadian patients. The use of VRQOL tools alongside anatomic outcomes provide a more comprehensive overview of patients' experiences and satisfaction after surgical intervention.

Practice patterns of Canadian vitreoretinal specialists in diabetic macular edema treatment.

OBJECTIVE: To establish the practice patterns of Canadian vitreoretinal (VR) specialists in the treatment of diabetic macular edema (DME). DESIGN: A survey was mailed, faxed, e-mailed, and published online for access by all Canadian VR specialists. PARTICIPANTS: All VR specialists identified from the Canadian Ophthalmology Society directory and the Canadian Retina and Vitreous Society directory. METHODS: A 19-item survey investigating treatment of DME was mailed to all VR specialists. A reminder fax and e-mail was sent with the survey attached. In all correspondence, physicians were given information regarding an available online version of the survey. The survey data was descriptively analyzed with the Statistical Package for the Social Sciences. RESULTS: With clinically significant macular edema (CSME) that is either away from the foveal avascular zone (FAZ) or diffuse, the most common first-line treatment option was macular photocoagulation 48 (78.8%) and 33 (54.1%), respectively. For microaneurysms within the FAZ, 33 (54.1%) of respondents chose intravitreal antivascular endothelial growth factor agents as their first-line treatment. In all, 51 respondents (83.6%) felt that vitrectomy played a role in the management of treatment-resistant CSME. Before utilizing intravitreal triamcinolone acetonide (IVT) injections, 34 (55.7%) of respondents did use a topical steroid trial to look for raised intraocular pressure whereas 16 (26.2%) of respondents did not use IVT injections at all. CONCLUSIONS: This survey provides valuable practical information on how DME is currently being treated in Canada and may serve as a baseline to assess how these patterns evolve over time.

Brachial plexus neuropathy secondary to postoperative prone positioning for macular hole surgery.

PURPOSE: To report a case of unilateral brachial plexus neuropathy after prone positioning for macular hole repair. METHODS: Case report. RESULTS: After 7 days of strict prone positioning post-macular hole surgery, a 60-year-old patient developed severe pain and weakness in the left arm. Neurologic examination, imaging, and electromyography showed that the patient developed a unilateral brachial plexus neuropathy. Her strength and pain quickly improved after hospitalization and treatment with intravenous solumedrol, pain control, and physiotherapy. Her best-corrected vision improved from 20/400 to 20/40, however, she was left with frozen shoulder syndrome. CONCLUSION: After macular hole surgery, prone positioning with persistent abduction of the shoulder such that the patient's hands rest above the head may put patients at risk for a brachial plexus neuropathy. However, this risk may be minimized by the use of positioning assistive devices, reducing the duration in the prone position, instituting frequent breaks, and warning patients to look for signs of neuropathy.

A trial of topical prednisolone acetate before intravitreal triamcinolone acetonide decreases intraocular pressure spikes.

OBJECTIVE: To compare adverse intraocular pressure (IOP) spikes in patients receiving intravitreal triamcinolone acetonide (IVTA) in 2 cohorts: (i) patients who underwent a topical prednisolone acetate trial (PAT) without incurring a short-term IOP rise, and (ii) control patients who did not undergo a PAT. DESIGN: Retrospective cohort study. PARTICIPANTS: Charts of all patients who underwent any intravitreal injection during the study period were reviewed (n = 1150). METHODS: Patients in the PAT group received a 6-week course of prednisolone acetate 1% 4 times per day and had an IOP that did not rise above 25 mm Hg or above 8 mm Hg over the IOP in the contralateral eye. Patients undergoing a PAT and having a short-term IOP rise were not studied. Control patients did not receive a PAT. All patients received 12-20 mg of IVTA. Patients were followed for a minimum of 6 weeks and follow-up lasted for 1 year or until intraocular surgery or another IVTA injection was performed. RESULTS: There were 97 patients in the PAT cohort and 75 control patients. Patients in the PAT cohort had a lower proportional rise between maximum IOP and baseline (43%) compared with controls (64%) (p = 0.035). Patients in the PAT group also had a lower risk of incurring a 40% (p = 0.05), 60% (p = 0.018), and 100% (p = 0.045) increase in maximum IOP (vs baseline) compared with controls and were less likely to require glaucoma filtration surgery (p = 0.035). CONCLUSIONS: Patients undergoing a PAT who did not have a subsequent short-term IOP rise had a lower risk of severe IOP spikes after IVTA compared with those patients receiving IVTA but not having undergone a PAT.

Comparison of the in vitro toxicity of indocyanine green to that of trypan blue in human retinal pigment epithelium cell cultures.

PURPOSE: To compare the in vitro toxicity of indocyanine green (ICG) to that of trypan blue (TB) in human retinal pigment epithelium cell cultures. The use of ICG and TB in macular hole surgery is discussed. DESIGN: In vitro cell biology experimental study. METHODS: The ICG dye and TB were applied to ARPE-19, a commercially available human retinal pigment epithelium cell line. Cultures were established and maintained according to supplier protocols. The ICG dye, TB or Hank's balanced salt solution (controls) were then applied to the cells at varying concentrations and over various exposure periods. Fiberoptic light was also applied to cells to assess for the possibility of a potentiating phototoxic effect. Cell viability fractions were determined using a well-studied mitochondrial dehydrogenase assay. RESULTS: The TB was not toxic to the retinal pigment epithelium cell cultures at any concentration or over any period of exposure, whereas ICG dye demonstrated dose-dependent and exposure-dependent toxicity. The ICG dye was found to be toxic to the cells at all tested concentrations between 5.0 mg/ml (stock concentration, 26.1% cell survival) and 0.5 mg/ml (92.8% cell survival) over a 3-minute exposure. No toxicity to TB was seen at the stock concentration of 1.5 mg/mL. Addition of light to the cultures did not significantly alter cell viability with either dye. Long periods of exposure, 2 hours, 24 hours, and 72 hours, to minute concentrations of either dye did not produce significant cell death. CONCLUSIONS: Indocyanine green demonstrates more toxicity than TB to human retinal pigment epithelium cell cultures. This is independent of any phototoxic potentiating effect of fiberoptic light or solvent toxicity. A clinically useful concentration of 0.5-mg/ml ICG causes low cytotoxicity at 3 minutes' exposure (cell survival 92.8%) and shows no detectable toxicity at 1-minute exposure (cell survival 102%).

Central serous chorioretinopathy in a patient taking sildenafil citrate.

A 37-year-old man presented with decreased vision in the right eye following increased use of sildenafil citrate. The visual and clinical findings worsened during the following week with continued use and then resolved rapidly with discontinuation of sildenafil citrate.