A Novel Combination Point-of-View (POV) Action Camera Recording to Capture the Surgical Field and Instrument Ergonomics in Oculoplastic Surgery.

PURPOSE: To evaluate a novel combination head-mounted/chest-mounted point-of-view recording system for oculoplastic surgical procedures. METHODS: The point-of-view head camera captures the surgical field, while the point-of-view chest camera captures a wide field of view to record instrument ergonomics. Various methods of recording were trialed. RESULTS: The head camera with a narrow field of view was better for recording fine details of the surgical field. The chest camera recording a wide field of view was optimal for recording hand positions. Stereoscopic recording of the instrument ergonomics was helpful in relaying the relative positions of the surgeon's hands and instruments. CONCLUSIONS: Point-of-view cameras are cost-effective means of recording oculoplastics procedures. The authors feel simultaneously recording the surgeon's ergonomics and the corresponding instrument movements within the surgical field, from the "surgeon's view", will augment surgical education.

Efficacy of gonioscopy-assisted transluminal trabeculotomy in advanced-age glaucoma patients.

BACKGROUND: The prevalence and severity of many etiologies of glaucoma increase with age, often requiring surgery later in life. Surgery in the most aged demographic, however, poses multiple unique physiologic and psychosocial challenges with variable outcomes. In this study, we evaluate the efficacy and safety of gonioscopy-assisted transluminal trabeculotomy (GATT) in an advanced-age population (>85 years of age). METHODS: This is a single-centre retrospective cohort study of consecutive patients who underwent GATT at or above 85 years of age. This included patients with GATT of any circumferential extent (90°-360°) with or without concurrent phacoemulsification cataract surgery. The primary outcome measure was proportion of successful surgeries at 1 year by the "complete success" criteria (intraocular pressure [IOP] <17 mm Hg on no medications 3 months after surgery with no additional interventions). Secondary outcomes included proportion of successful surgeries by alternative criteria, cross-sectional analyses of IOPs and medication use, and analyses of postoperative complications and interventions. RESULTS: Forty eyes of 31 patients were included in the study. Mean baseline IOP was 16.75 ± 7.33 mm Hg on 1.60 ± 1.43 classes of medication. At 1 year, the cumulative survival by Kaplan-Meier analysis was 46.6%. There was a statistically significant reduction in IOP at all postoperative time points to a mean of 11.78 ± 3.07 mm Hg at the last follow-up. There were postoperative complications in 18 eyes, with hyphema and corneal edema accounting for the majority. CONCLUSIONS: This study provides evidence that GATT is a safe and effective intervention in advanced-age glaucoma populations.

Gonioscopy-assisted transluminal trabeculotomy is an effective surgical treatment for uveitic glaucoma.

BACKGROUND: To assess the efficacy and safety of gonioscopy-assisted transluminal trabeculotomy (GATT) in uveitic glaucoma (UG). METHODS: A retrospective interventional case series in which 33 eyes of 32 patients with UG underwent GATT with or without concomitant cataract extraction and intraocular lens implantation (CE/IOL) at three Canadian treatment centres from October 2015 to 2020. The main outcome measure was surgical success defined as an intraocular pressure (IOP) ≤18 mm Hg and at least one of the following: IOP within one mm Hg of baseline on fewer glaucoma medications as compared with baseline or a 30% IOP reduction from baseline on the same or fewer medications. Secondary outcome measures were IOP, medication usage and surgical complications. RESULTS: Mean patient age (mean±SD) was 49±16 years (range: 18-79) and 44% were female. GATT was performed as a standalone procedure in 52% of cases and the remainder were combined with CE/IOL. Surgical success was achieved in 71.8% (SE: 8.7%) of cases. Mean preoperative IOP (±SD) was 31.4±10.8 mm Hg on a median of 4 medications. 59% of patients were on oral carbonic anhydrase inhibitors (CAIs) prior to surgery. After 1 year, average IOP was 13.8 mm Hg on a median 1 medication, with 6% of patients being on oral CAIs. No sight threatening complications occurred during surgery or follow-up. CONCLUSION: GATT is an effective surgical strategy in the management of UG. This microinvasive conjunctival-sparing procedure should be considered early in these patients.

Segmental Suture Gonioscopy-Assisted Transluminal Trabeculotomy: Comparison of Superior Versus Inferior Hemisphere Outcomes.

PRCIS: Analysis of efficacy, safety, and risk factors for failure of superior versus inferior 180-degree segmental gonioscopy-assisted transluminal trabeculectomy showed no significant difference between approaches, with novel risk factors for failure identified. PURPOSE: Compare the efficacy, safety, and risk factors for failure of superior versus inferior 180-degree segmental suture gonioscopy-assisted transluminal trabeculotomy (GATT). DESIGN: Multicenter, retrospective interventional cohort study of 297 eyes of 243 glaucomatous patients, which underwent superior or inferior 180-degree suture hemi-GATT surgery combined with phacoemulsification at one of 3 Canadian ophthalmological surgical centres in Calgary, Alberta or Toronto, Ontario. MAIN OUTCOME MEASURES: The primary outcome measure was the hazard ratio (HR) of failure for the "primary success" criteria. "Primary success" was defined as an intraocular pressure (IOP) <18 mm Hg and either 1) IOP reduced by ≥20% from baseline on the same number of IOP-lowering medications or 2) IOP ≤ baseline on fewer medications. Secondary outcome measures included HRs of failure for alternative criteria ("complete success", "qualified success" and "20% IOP reduction"), cross-sectional analysis, and Cox proportional hazard analysis for risk factors associated with increased failure for the complete cohort. RESULTS: Baseline characteristics were similar between groups. The crude and adjusted HR of failure for the "primary success" criteria for superior surgeries relative to inferior surgeries were 1.27 (95% CI = 0.86-1.88) and 1.50 (95% CI = 0.91-2.46), with no statistically significant difference between approaches. Of the secondary criteria, there was statistical significance in favor of inferior surgeries only for crude analysis of the "20% reduction" criteria (1.40/1.27 (95% CI = 1.01-1.92). Increased risk of failure by the "primary success" measure for either intervention was seen with primary open angle glaucoma, advanced disease, and age below 70 years. There were no significant differences in the frequency of postoperative complications between cohorts, which were present in 72 superior (44.4%) and 67 inferior (49.6%; P value = 0.41) eyes; mostly early postoperative hyphema, iritis, and corneal edema. CONCLUSIONS: This retrospective study showed no difference in inferior versus superior 180 degrees of hemi-GATT/phacoemulsification cataract surgeries through the majority of analyses. Nonmodifiable factors including glaucoma type, advanced disease, and younger age were associated with a significantly higher risk of failure in this cohort. Further study is warranted.

Face and Content Validity of an Artificial Eye Model for Secondary Intraocular Lens Fixation via Yamane Technique.

Purpose: To assess the face and content validity of an artificial eye model for secondary intraocular lens (IOL) fixation via the Yamane technique. Methods: Ophthalmologists and residents participated in a 90-minute simulation session on secondary IOL fixation via the Yamane technique. Hands-on practice of this technique was performed on an artificial eye, the Bioniko Okulo BR8. After, all ophthalmologists answered an 18-question survey assessing the face and content validity of the model. Survey responses were recorded on a 5-point double-headed Likert scale, ranging from strongly agree (1)-to-strongly disagree (5) (Figure 1). Results: Twenty-three surveys were completed. Respondents rated the survey with a median response of 1 (strongly agree)-to-3 (neutral). Highest ratings for the model were received for "usefulness for training residents", and "easier to set up and clean-up compared to a cadaver". Lowest ratings were received for realism of the model compared to cadaveric eyes. Statistical analysis revealed no significant difference among identified groups. Ratings for face and content validity were viewed favorably, both with an overall median response of 2.00 (agree). Conclusion: The Bioniko Okulo BR8 shows promise as a valid tool for practicing secondary IOL fixation via the Yamane technique. Considering recent guidelines in competency-based ophthalmology education programs, this model may be a valuable tool over traditional techniques for teaching and improving surgical skill amongst trainees.

Comparison of 3D heads-up display system with conventional surgical microscopy for minimally invasive glaucoma surgery on an artificial eye model.

OBJECTIVE: To survey ophthalmic surgeons' opinions comparing a novel three-dimensional (3D) heads-up display system with a conventional surgical microscopy for minimally invasive glaucoma surgery (MIGS) on an artificial eye model. MATERIALS AND METHODS: Twenty-one ophthalmologists at the 2021 Canadian Ophthalmological Society Annual Meeting in Halifax, Nova Scotia, underwent a 90-minute skills-transfer course on MIGS. Using an artificial eye model (SimulEYE iTrack Model; InsEYE LLC, Westlake Village, Calif.), participants engaged in hands-on practice of MIGS via both a 3D heads-up display system (3D HUDS) (Zeiss Artevo 800; Carl Zeiss Meditec, Jena, Germany) and a conventional surgical microscope. Following completion, participants and instructors answered a 16-question survey comparing the 2 systems (3D HUDS vs conventional surgical microscope). Survey responses were recorded on a 9-point double-headed Likert scale ranging from strongly favour 3D HUDS (1) to strongly favour conventional surgical microscopy (9). Mann-Whitney U nonparametric analysis was used to compare instructor versus participants and experts versus nonexperts. RESULTS: Survey ratings favoured the 3D HUDS over the conventional surgical microscopy, with respondent ratings for all survey questions ranging from a response of 1 (strongly favour 3D HUDS) to 5 (equal). Mann-Whitney U statistical analysis revealed no significant difference between instructor versus participant as well as between expert versus nonexpert. Most ratings for the 3D HUDS were received for ergonomic setup of the surgical modality, depth of field (or) field of view, and usefulness in training residents for MIGS. Equal ratings for the 3D HUDS and conventional surgical microscope were received for system malfunctions and lag during surgery. CONCLUSIONS: The 3D HUDS was favoured over conventional microscopy for the performance of simulated MIGS by ophthalmologists with varying levels of experience. The survey results suggest that the 3D HUDS in an artificial eye model is useful for teaching minimally invasive glaucoma surgery, particularly with the advent of competency-based ophthalmology education programs.

Safety and efficacy of micropulse transscleral cyclophotocoagulation: 2-year follow-up in a tertiary Canadian centre.

OBJECTIVE: To describe the long-term results of patients undergoing micropulse cyclophotocoagulation (MPCPC). METHODS: Retrospective review of patients undergoing MPCPC with 1 surgeon between July 2016 and January 2017. Data collected included preoperative intraocular pressure (IOP), number of medications, daily acetazolamide use, and whether inferior, superior, or circumferential MPCPC was performed. This was assessed at postoperative week 1 and postoperative months 1, 3, 6, 12, 18, and 24. RESULTS: A total of 49 patients undergoing MPCPC with 2-year follow-up data was included. Ages ranged from 20 to 91 years (mean age, 69 years; 50% female). Following MPCPC, IOP was significantly lower at all points of follow-up (p < 0.05). At 2-year follow-up, the average IOP was 15 mm Hg (35% reduction). Six patients remained on acetazolamide (average daily dose, 333 mg). Average number of medications had decreased to 2.6 (p > 0.05). No significant structural complications occurred, but 53% required repeat MPCPC applications. The most common complication was failure requiring a secondary IOP-lowering surgical procedure. This occurred in 33% of patients. Subsequent glaucoma surgeries included gonioscopy-assisted transluminal trabeculotomy, iStent, Xen glaucoma implant, and Ahmed glaucoma valve. CONCLUSIONS: MPCPC was successful in reducing IOP in conjunction with a nonsignificant reduction in topical glaucoma medications. However, a large proportion of patients required repeat micropulse applications or invasive glaucoma surgery to achieve IOP control. These results suggest that the clinical efficacy of MPCPC may be lower than that reported in the literature.

Assessing the quality of online information on glaucoma procedures.

OBJECTIVE: To investigate the quality of information related to glaucoma procedures found online using 2 different assessment tools. DESIGN: Cross-sectional survey of 100 web sites found via Google search engine. METHODS: The terms "peripheral iridotomy" and "trabeculectomy" along with synonymous keywords were inputted into Google's search engine. The first 50 functional websites for each term were assessed by 2 independent raters using the DISCERN instrument as well as a quality assessment tool by the Journal of the American Medical Association (JAMA). Statistical analysis included an evaluation of intra-rater reproducibility and interclass correlation between the 2 scales. MAIN OUTCOME MEASURES: (i) Quality of web site content based on DISCERN and JAMA scores, (ii) quality of web site based on categorization of web site (iii), intra-rater reproducibility of each scale, and (iv) interclass correlation between the 2 rating scales. RESULTS: Only 22% of the web sites for peripheral iridotomy and 34% of the web sites for trabeculectomy met all the criteria for JAMA's quality assessment. The mean DISCERN scores for peripheral iridotomy and trabeculectomy were 44 and 43.7, respectively, indicating poor quality. For the DISCERN scale, level of agreement between raters for each question ranged from κ = 0.550 (95% confidence interval [CI] 0.700-1.026) to κ = 0.884 (95% CI 0.751-1.017). For the JAMA 4 scale, level of agreement for each question ranged from κ = 0.874 (95% CI 0.734-1.01) to κ = 1.00. CONCLUSION: Our study indicates that information found online for two common ophthalmic procedures is of variable and poor quality. Thus, patients may be receiving misinformation online and better measures need to be implemented to avoid the dissemination of low-quality health information.

Factors Affecting the Use of Medical Articles for Citation and Academic Reference.

Introduction: Increases in publication quantity and the onset of open access have increased the complexity of conducting a literature search. Bibliometric markers, like impact factor (IF), have traditionally been used to help identify high-quality research. These markers exist amongst a variety of other factors, which poses the following question: what factors are examined when considering articles for clinical and academic research? Objective: To determine what factors are involved when authors choose citations to include in their publications. Methods: A voluntary and anonymous questionnaire-based survey was distributed to medical students, residents, and faculty from multiple medical schools across Canada during the 2020/2021 academic year. Survey ratings were scored on a 5-point Likert scale and open word response. Results: The study collected 156 complete sets of responses including 78 trainees (61 medical students and 17 residents), and 78 faculty. Language of the article (3.93) and availability on PubMed/Medline (3.77) were found more important than country of origin (2.14), institution (2.26), and IF (2.97). Trainees found the following factors more important than faculty: year of publication (3.94 vs 3.47, p = 0.0016), availability on Google/Google Scholar (2.51 vs 1.88, p = 0.0013), Open-access (2.46 vs 1.87, p = 0.0011), and Free access (2.73 vs 2.31, p = 0.049). Conclusion: Our study identified differences in faculty and trainee literature search preferences, bias towards English language publications, and the movement towards online literature sources. This knowledge provides insight into what biases individuals may be exposed to based on their language and literature search preferences. Future areas of research include how trainees' opinions change over time, identifying trainee ability to recognize predatory journals, and the need for better online journal article translators to mitigate the language bias. We believe this will lead to higher quality evidence and optimal patient care amongst healthcare workers.

Face and content validity of an artificial eye model for Ab-Interno Goniotomy.

PURPOSE: To determine the face and content validity of an artificial eye model for ab-interno goniotomy (SimulEYE KDB model, InsEYEt, Westlake Village, CA) by surveying ophthalmologists with varying experience using a Kahook Dual Blade (KDB; New World Medical, Rancho Cucamonga, CA, USA) following a 90-min wet-lab course using the model. PARTICIPANTS: Overall 13 ophthalmologists participated following a surgical simulation session on goniotomy using the goniotomy blade at the 2019 Canadian Ophthalmological Society annual meeting. METHODS: A 17-question survey to assess the face and content validity of the model was given immediately following the surgical simulation session on goniotomy using the goniotomy blade. Responses to each survey question were recorded on a 5-point Likert scale ranging from (1) strongly agree to (5) strongly disagree. RESULTS: Respondents rated statements regarding the model with a median response of 1 (Strongly Agree) to 3 (Neither agree or disagree). Mann-Whitney U nonparametric analysis revealed no significant difference in responses between instructor vs. non-instructor or between prior experience vs. no prior experience for any of the survey statements. The model received highest survey ratings for utility in training residents, acquisition of surgical skills, accessibility, and higher likelihood of success with the procedure than theory and observation alone. Lowest ratings were for realism of the model compared to a human cadaveric eye. CONCLUSION: Our results suggest the SimulEYE KDB model is a reasonably cost-effective solution for simulating angle-based surgeries. Additionally, our project shows that experienced ophthalmologists found the artificial eye models useful and helpful for angle-based surgery training.

Competency-based medical education in ophthalmology residency training: a review.

Competency-based medical education (CBME) is an outcomes-based training model that has become the new standard of medical education internationally. Regulatory and accrediting bodies have responded by establishing key competencies that residency programs may use to reshape their curricula. Available literature on the implementation of CBME in ophthalmology residency training programs across North America was examined. Ophthalmology-specific residency training objectives and milestones have been proposed within North America in the last 4 years. Curriculum guidelines and implementation blueprints and principles have also been proffered from various sources internationally but have met with some barriers. Assessment tools within ophthalmology have seen the most innovative development within the domain of surgical skills objectives. Competencies outside of the medical expert and patient care roles have proven more challenging to teach and assess. One ophthalmology program in Canada has undergone early implementation of a novel CBME curriculum. There is still considerable work to be done to successfully implement CBME curricula within ophthalmology residency programs in North America. Collaborative efforts to develop customizable curricula, tackle implementation barriers, and create specific assessment modalities will assist programs in meeting the competency mandates of CBME.

Ab Interno Canaloplasty in Open-angle Glaucoma Patients Combined With In Vivo Trypan Blue Aqueous Venography.

PURPOSE: To demonstrate canalogram patterns observed when trypan blue tracer is combined with oculoviscoelastic device during ab interno canaloplasty, and discuss surgical results and potential implications for diagnosis, prognosis, and treatment. METHODS: This is a retrospective small case series study. RESULTS: The authors performed this procedure on 5 patients with informed consent with 4 to 18 months of follow-up. All procedures have been complication free. The average preoperative intraocular pressure was 16.4 mm Hg with an average number of topical glaucoma medications being equal to 3.6. Postoperatively, the average intraocular pressure for the group was reduced to 13 mm Hg with a concurrent drop in the average number of topical medications used equaling 1.8. CONCLUSIONS: Currently, there are limited practical options to evaluate the patency of the aqueous outflow system in our patients. The primary purpose of this paper is to describe canalogram patterns observed during ab interno canaloplasty with trypan blue. This technique may allow us to further our understanding of the aqueous outflow system and its role in the underlying pathophysiology of glaucoma. Further research is required to evaluate the prognostic and diagnostic significance of this technique.

Management of Ocular Surface Disease in Glaucoma: A Survey of Canadian Glaucoma Specialists.

PRéCIS:: Ocular surface disease (OSD) in glaucoma is an area for improvement in the management of patients with glaucoma. This study explores the knowledge of glaucoma subspecialists toward OSD in glaucoma, then provides a suggested treatment algorithm. PURPOSE: To assess the attitudes, knowledge, and level of comfort of Canadian glaucoma specialists with respect to the assessment and management of OSD among patients with glaucoma. METHODS: Ophthalmologist members of the Canadian Glaucoma Society with fellowship training in glaucoma were contacted to participate in this cross-sectional survey study. Responses were recorded to statements regarding attitudes toward OSD in glaucoma, and assessment and management modalities. These were recorded primarily in the form of a Likert scale rated 1 to 7 from "strongly disagree" to "strongly agree." Descriptive statistics were generated, and mean and SD for responses on Likert scales. RESULTS: Thirty-six responses were included. All respondents agreed that comprehensive management of OSD could improve quality of life, 97% agreed it could lead to better glaucoma outcomes, whereas only 22% agreed it is presently being adequately managed in glaucoma practices. Respondents were asked to list all treatment modalities they felt knowledgeable about, ranging from 100% for optimizing topical glaucoma therapies to 31% for serum tears. Nearly all respondents (92%) agreed that a suggested algorithm for the treatment of OSD in glaucoma could improve their approach to management. CONCLUSION: OSD is a common comorbidity of glaucoma. Although respondents overwhelmingly agreed that comprehensive management of OSD may lead to improved quality of life and glaucoma-related outcomes, only a small percentage felt it was presently adequately managed. Increasing knowledge related to the assessment and management of OSD in glaucoma may in the future improve patient care.

Competency-Based Education Assessment Tools for Laser Capsulotomy, Peripheral Iridotomy, and Selective Laser Trabeculoplasty.

PURPOSE: To produce Competency-Based Education Assessment Tools (C-BEAT) for performance of neodymium-doped yttrium aluminum garnet (Nd:YAG) laser capsulotomy, laser peripheral iridotomy (LPI), and selective laser trabeculoplasty (SLT) on an artificial eye model that can be used in competency-based medical education (CBME) of ophthalmology residents. DESIGN: Survey. PARTICIPANTS: Eight content experts (residency program director and faculty members involved in ophthalmology resident training). METHODS: Task-specific checklists were created to assess the performance of Nd:YAG capsulotomy, LPI, and SLT on artificial eye models designed for each of these procedures, as well as a global rating scale (GRS). A modified Delphi process was used to establish face and content validity of the C-BEAT for lasers. Eight content experts participated in the Delphi process, and the consensus was achieved after 4 rounds. MAIN OUTCOME MEASURE: Survey responses. RESULTS: Final versions of checklists for Nd:YAG capsulotomy, LPI, and SLT, and a GRS for these laser procedures were produced with face and content validity. Modifications to the energy settings and the number of applications in the capsulotomy and peripheral iridotomy were implemented into the checklist and instructions, because the artificial models were not identical in their responses to the laser applications compared with real tissue. CONCLUSIONS: The C-BEAT for lasers can be used in an examination setting within ophthalmology residency training programs to establish competency in these procedures before performing them on real patients. These tools help to meet the demand for assessment modalities within a CBME model that is being implemented into residency training worldwide. To establish interrater and construct validities, further studies are required.

Surgeon and Assistant Point of View Simultaneous Video Recording.

Video recording has become a very common practice in surgery and is one of the paramount methods to teach proper surgical techniques. Traditionally it has been limited by a variety of factors including cost, the need for constant camera reposition, and the use of external photographers, which is both costly and labor-intensive. We describe the use of dual modified point of view (POV) GoPro head mounted cameras to record synchronized POV surgery for the purpose of training surgical assistants. POV cameras are inexpensive, easy to use and manipulate. The GoPro camera was mounted using a head strap on both the surgeon's and surgical assistant's head, providing different optimal views. We used the GoPro Hero4 Silver for the surgeon and the GoPro Hero3+ Black Edition for the assistant. The lens used was optimized for our purposes. With the modified camera for the primary surgeon, the magnification was satisfactory in recording of fine details, and provided a usable depth of field and field of view. We found that using two synchronized POV GoPro head mounted cameras was an innovative way to record otolaryngology surgery and provided excellent video footage which can be used for the education of both surgeons and surgical assistants.

Cadaver corneoscleral model for angle surgery training.

PURPOSE: To assess a new training model (Tackdriver) for new-generation microinvasive glaucoma surgeries (MIGS). SETTING: Resident training centers in Canada. DESIGN: Evaluation of technology. METHODS: Human cadaver corneoscleral rims recovered after Descemet-stripping endothelial keratoplasty or not suitable for transplantation were acquired from an eye bank. The tissue was fixated with a single tack through the center of the cornea, which was inverted in a concave fashion. A water-based medical lubricant was used for placement of a goniolens after visualization of the anterior chamber and the trabecular meshwork. Microbypass stent (iStent) insertion and gonioscopy-assisted transluminal trabeculotomy (GATT) were practiced on this model. The model was qualitatively assessed for ease of preparation, accuracy of surgical simulation, and the number and variety of MIGS procedures that can be performed. RESULTS: Efficient high-volume training was performed for microbypass stent insertion using first-generation and second-generation microbypass stents. The GATT procedure was also performed as a final step in a titratable fashion in 90-, 180-, or 270-degree segments or a complete 360-degree treatment. The model simulated bimanual angle surgery with good fidelity. CONCLUSIONS: The training model allowed for high-volume bimanual MIGS training for techniques such as microbypass stent insertion and removal as well as GATT. Preparation was relatively simple, efficient, and cost-effective compared with other models. Inverting the specimen allowed the trainee to practice MIGS techniques independent of the tissue's corneal clarity. Other MIGS techniques and angle training procedures can be adopted to this model.

K-RIM (Corneal Rim) Angle Surgery Training Model.

PURPOSE: To develop an angle surgery training model for training an array of microincisional glaucoma surgery (MIGS) procedures. METHODS: We describe a method for preparing an angle surgery training model using human cadaveric corneoscleral rims. The model provides realistic tactile tissue simulation and excellent angle visualization requiring bimanual technique. Corneoscleral rims may be used multiple times and are prepared at low cost, allowing for a high volume of practice surgeries. RESULTS: This model allows for practice in bimanual surgical training using the gonioscopy lens for visualize alongside surgical tools. The in vivo surgical conditions and limited tactile feedback are recreated using human cadaveric eyes which nonhuman models fail to provide. Our model is prepared at low cost, with relative ease and also provides appropriate positioning of Schlemm canal and for high volume of practice as the canal can be used in 90-degree segments. CONCLUSIONS: Few angle surgery training models currently exist and none provide these necessary features. The model presented here aims to meet the growing demand for adequate training models required for technically advanced MIGS techniques.

Comparison of the incidence of opacification of Hydroview hydrogel intraocular lenses with the ophthalmic viscosurgical device used during surgery.

PURPOSE: To determine the effect of intraoperative ophthalmic viscosurgical devices (OVDs) on late opacification of the Hydroview hydrogel intraocular lens (IOL) (Bausch & Lomb Surgical). SETTING: Hamilton Health Sciences, McMaster University, Hamilton, Ontario, Canada. METHODS: A retrospective study of 949 cases of Hydroview IOL implantations from February 1998 to September 2000 was conducted. Of the 949 implantations, 462 were performed by 1 surgeon (J.H.S.) using Viscoat (sodium chondroitin sulfate 4.0%-sodium hyaluronate 3.0%) and 487 were performed by a second surgeon (W.A.N.) using Biolon (sodium hyaluronate 1.0%). Surgical techniques were identical with the exception of surgeon OVD preference. The number of IOLs opacifying and requiring explantation was determined in each group. RESULTS: Seventy-one Hydroview IOLs had surface calcification deposits that presented a mean of 39 months postoperatively. Twenty-two IOLs opacified sufficiently to warrant a recommendation of IOL explantation; 20 IOLs were explanted, and 2 surgeries were cancelled due to death or disability. In all cases of opacification, Viscoat had been used intraoperatively. This represented a 15.4% incidence of opacification in the Viscoat group, with 31.0% cases severe enough to warrant a recommendation of explantation. CONCLUSION: The results suggest that the intraoperative use of Viscoat has a facilitating role in the development of late calcification and opacification of the Hydroview IOL.

Acanthamoeba keratitis: persistent organisms without inflammation after 1 year of topical chlorhexidine.

PURPOSE: To report a non-contact lens wearer with persistent Acanthamoeba organisms in the cornea after being treated with medical therapy that included topical chlorhexidine as 1 agent for 1 year. METHODS: A 53-year-old man with Acanthamoeba keratitis was treated with medical therapy for >1 year, followed by a penetrating keratoplasty. RESULTS: Histopathologic examination of the keratoplasty specimen revealed viable-appearing Acanthamoeba cysts and trophozoites within the deep corneal stroma in a focus of corneal scarring. CONCLUSIONS: The use of chlorhexidine as 1 agent in the medical management of Acanthamoeba keratitis may not eradicate the organisms.