Allan R. Slomovic

Comparison of Posterior Lamellar Keratoplasty Techniques to Penetrating Keratoplasty

PURPOSE To describe the visual outcomes and intraoperative and postoperative complications after penetrating keratoplasty (PK), deep lamellar endothelial keratoplasty (DLEK), Descemet stripping endothelial keratoplasty (DSEK), and Descemet stripping automated endothelial keratoplasty (DSAEK) and to compare the results with those of previously reported series. DESIGN Prospective, comparative, nonrandomized study. PARTICIPANTS One hundred seventy-seven eyes of 161 consecutive patients who had corneal edema resulting from Fuchs endothelial dystrophy, pseudophakic bullous keratopathy, aphakic bullous keratopathy, failed graft or iridocorneal endothelial syndrome. METHODS All patients underwent either PK, DLEK, DSEK, or DSAEK at the Cornea Service of the Toronto Western Hospital. MAIN OUTCOME MEASURES Uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), manifest refraction, corneal endothelial counts, and postoperative complications. RESULTS The average 12-month postoperative BSCVA was 20/53 in the PK group, 20/80 in the DLEK group, 20/56 in the DSEK group, and 20/44 in the DSAEK group. The mean spherical equivalent was similar between groups, but tended toward hyperopia in the DSEK and DSAEK groups. The average refractive astigmatism was 3.78+/-1.91 diopters (D) in the PK group and 1.61+/-1.26 D, 1.86+/-1.1 D, and 1.36+/-0.92 D in the DLEK, DSEK, and DSAEK groups, respectively (P<0.0001). Early postoperative donor disc dislocations occurred in 6 (8.8%) patients in the DLEK group, 2 (12.5%) in the DSEK group, and 7 (15.6%) in the DSAEK group (P = 0.0004). Detached grafts were reattached and repositioned by injecting an air bubble to press the donor against the recipient cornea. Primary graft failure occurred in 1 (2.1%) of the PK cases, 2 (2.9%) of the DLEK cases, and 1 (2.2%) of the DSAEK cases; all underwent the same procedure successfully. Average cell loss at 1 year after surgery was 40.11% and was similar in the 4 groups. CONCLUSIONS The DSAEK surgery enabled rapid and better UCVA and BSCVA when compared with PK, DLEK, and DSEK, with significantly lower astigmatism. Endothelial cell loss was similar, but the dislocation rate was significantly higher in the DSAEK group.

Comparison of Three Different Techniques of Corneal Transplantation for Keratoconus

PURPOSE To compare the visual outcomes following deep anterior lamellar keratoplasty (DALK), penetrating keratoplasty (PK), and manual top-hat PK (TH-PK) in subjects undergoing corneal transplantation for keratoconus (KC). DESIGN A retrospective comparative case series. METHODS settings: Cornea clinic at the Toronto Western Hospital. study population: Fifty patients who underwent corneal transplantation for KC: 17 eyes underwent DALK, 20 eyes underwent traditional PK, and 13 had TH-PK. main outcome measures: Preoperative and postoperative uncorrected and best spectacle-corrected visual acuity (UCVA, BSCVA), high-order aberrations (HOA), complication rate, and endothelial cell counts. RESULTS The median BSCVA at 12 months follow-up was 20/40 in the DALK eyes and 20/30 in the traditional PK and TH-PK eyes. The mean final spherical equivalent power in the three groups was less than -1 diopter (D). The median astigmatism was less than 3.5 D in the three groups. Complication rates were similar for three groups, although the DALK group tended toward more complications. Although DALK and TH-PK procedure results in significantly shorter time to suture removal (P < .01), they caused increased levels of HOAs (P = .02). Endothelial cell counts at 12 months were significantly higher in DALK and TH-PK eyes when compared to the traditional PK eyes (P < .001). CONCLUSIONS DALK, PK, and TH-PK provide comparable visual outcomes in keratoconus patients. Although DALK and TH-PK induce more HOA, they speed up the time to suture removal and provide higher endothelial cell density at one year of follow-up.

Subconjunctival Bevacizumab Injection for Corneal Neovascularization

Purpose: To report on the clinical use of subconjunctival bevacizumab in patients with corneal neovascularization. Methods: The charts of 10 consecutive patients with corneal neovascularization who received subconjunctival injections of bevacizumab (2.5 mg/0.1 mL) were reviewed. Digital photographs of the cornea were graded by 2 masked observers for density, extent, and centricity of corneal vascularization. Image analysis was used to determine the area of cornea covered by neovascularization as a percentage of the total corneal area. Results: No significant ocular or systemic adverse events were observed during 3.5 ± 1.1 months of follow-up. Seven patients showed partial regression of vessels. The extent decreased from 6.0 ± 1.2 (SD) clock hours before the injection to 4.6 ± 1.0 clock hours after bevacizumab injection (P = 0.008). Density decreased from 2.7 ± 0.2 to 1.9 ± 0.3, respectively. (P = 0.007). No change was noticed in the centricity of corneal vessels. Corneal neovascularization covered, on average, 14.8% ± 2.5% (SD) of the corneal surface before the injections, compared with 10.5% ± 2.8% (P = 0.36, t test) after bevacizumab injection. Therefore, bevacizumab decreased corneal neovascularization by 29%. Conclusions: Short-term results suggest that subconjunctival bevacizumab is well tolerated and associated with a partial regression of corneal neovascularization.

SUBCONJUNCTIVAL BEVACIZUMAB INJECTION FOR CORNEAL NEOVASCULARIZATION IN RECURRENT PTERYGIUM

Purpose: We report on the use of subconjunctival bevacizumab on corneal vessel density in recurrent pterygia.Methods: The charts of 5 patients with recurrent pterygium, who received subconjunctival injections of bevacizumab (2.5 mg/0.1 ml) were retrospectively reviewed. Ophthalmic evaluation included Snellen visual acuity (VA), tonometry and complete examination before the injection and at 1 week and 1 and 3 months thereafter. Digital photographs of the eyes were analyzed by image analysis software to determine the area of cornea covered by new vessels as a percentage of the total corneal area. Results: No ocular or systemic adverse events were observed. No change in visual acuity was noted in any patient following the injection. The mean change in corneal vascularization after one bevacizumab injection was 0.03% ± 0.45, while after two injections the change was 0.025% ± 0.19 (both not statistically different than zero, t-test). Conclusions: Short-term results suggest that subconjunctival bevacizumab is well tolerated but does not cause regression of corneal vessels in recurrent pterygium.

Corneal graft outcome study.

Purpose. To determine overall 2-and 5-year corneal graft survival rates and to identify risk factors for corneal graft failure in our patient population. Methods. A retrospective chart review of 696 patients undergoing corneal transplantation performed by a single surgeon at The Toronto Western Hospital over a 7.5-year period. Results. A total of 468 eyes met the inclusion criteria for this study. Overall, the 2-and 5-year graft survival rates were 78.8% and 64.5%, respectively. In a univariate analysis, patient age, gender, history of glaucoma, preoperative diagnosis, type of operative procedure, and postoperative factors all were shown to be significantly associated with graft survival. In a multivariate analysis, six independent predictors of graft failure were identified: preoperative diagnosis, neovascularization of the graft, the presence of peripheral anterior synechiae, gender, occurrence of one or more rejection episodes, and age of the recipient at the time of corneal transplantation. Conclusions. Risk of graft failure can vary substantially within a population of patients receiving a corneal transplant. The outcomes of this study concur with the risk factors for corneal graft failure in the literature and can be used as prognostic guidelines for both surgeons and patients.

Visual function and patient experience after bilateral implantation of toric intraocular lenses

PURPOSE: To evaluate the efficacy, stability, predictability, and patient‐reported outcomes of bilateral toric intraocular lens (IOL) implantation in cases of cataract with preexisting astigmatism. SETTING: Fourteen universities, hospitals, or private practices, Canada. METHODS: Patients with cataracts and corneal astigmatism from 1.00 to 2.50 diopters (D) were included in a prospective study of bilateral AcrySof toric IOL implantation. Binocular uncorrected distance visual acuity (UDVA), manifest refraction, and IOL rotational stability were assessed 1 day and 1, 3, and 6 months postoperatively. Patients completed a questionnaire that assessed spectacle independence, visual disturbances, and satisfaction with vision (1 = completely unsatisfied; 10 = completely satisfied) preoperatively and 3 and 6 months postoperatively. RESULTS: The study included 117 patients (234 eyes). The binocular UDVA was 20/40 or better in 99% of patients and 20/20 or better in 63% of patients. The mean residual refractive astigmatism was 0.4 D ± 0.4 (SD). The spherical equivalent was within ±0.5 D of target in 77% of eyes. At last observation, IOL alignment was within ±5 degrees in 91% of eyes and within ±10 degrees in 99%. Sixty‐nine percent of patients reported never using distance spectacles. The frequency and severity of halos and glare were significantly reduced from preoperatively to postoperatively. Satisfaction with vision was rated 7 or higher by 94% of patients. CONCLUSION: Bilateral implantation of toric IOLs yielded excellent and stable visual outcomes that patients rated as highly satisfactory. Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned. Additional disclosures are found in the footnotes.

Retrospective contralateral study comparing descemet stripping automated endothelial keratoplasty with penetrating keratoplasty.

Purpose: To compare the visual outcomes and complications rate after penetrating keratoplasty (PKP) and Descemet stripping automated endothelial keratoplasty (DSAEK), in the fellow eye of the same subjects, and to evaluate the patients perspective on these operations. Methods: A retrospective cohort study was undertaken in the Cornea Clinic at the Toronto Western Hospital. We reviewed the records of 12 patients (24 eyes) who underwent PKP in one eye and DSAEK surgery in their fellow eye. Patients satisfaction for both procedures was evaluated using a subjective questionnaire. These techniques were compared for intraoperative and postoperative complications and visual and refractive outcomes including contrast acuity, contrast threshold, and high-order ocular aberrations (HOA). Results: All the patients in this study preferred the DSAEK operation. They reported faster recovery time [1.5 week in the DSAEK vs 5.3 weeks in the PKP operation (P = 0.01)], significantly less pain, and better visual outcomes with the DSAEK operation. Uncorrected visual acuity and best-corrected visual acuity were significantly better in the DSAEK operated eyes. The DSAEK surgery was associated with significantly less astigmatism (P = 0.0003) and ametropia. Contrast acuity was significantly better in the eye that underwent DSAEK procedure (P < 0.05), whereas contrast threshold was better in the PKP eye. The PKP operated eyes demonstrated increased level of HOA. Conclusions: Patients preferred the DSAEK operation compared with PKP. Better uncorrected visual acuity, best-corrected visual acuity, and contrast acuity together with avoidance of surgery-induced astigmatism and HOA are the main benefits of the DSAEK technique.

Shifting Trends in Bacterial Keratitis in Toronto: An 11-Year Review

OBJECTIVE To review the distribution, current trends, and resistance patterns of bacterial keratitis isolates in Toronto over the last 11 years. DESIGN Retrospective, observational, case series. PARTICIPANTS Microbiology records of suspected bacterial keratitis cases that underwent a diagnostic corneal scraping and cultures from January 1, 2000, through December 31, 2010, were reviewed. METHODS Culture results and antibiotic sensitivity profiles were reviewed and analyzed. MAIN OUTCOME MEASURES Distribution of the main isolated pathogens as well as in vitro laboratory minimum inhibitory concentration testing results to identify resistance patterns. RESULTS A total of 1701 consecutive corneal scrapings were taken during the 11 years of the study. A pathogen was recovered in 977 samples (57.4%), with bacterial keratitis accounting for 897 of the positive cultures (91.8%). The total number of Gram-positive and Gram-negative isolates was 684 and 213, respectively. We identified a decreasing trend in Gram-positive isolates (P = 0.016). The most common isolate overall was coagulase-negative Staphylococcus (CNS) and the most common Gram-negative bacteria isolated was Pseudomonas aeruginosa. Methicillin-resistant Staphylococcus aureus (MRSA) was present in 1.3% of the S aureus isolates, whereas methicillin-resistant CNS (MRCNS) was present in 43.1% of the CNS isolates. There was a trend toward increasing laboratory resistance to methicillin from 28% during the first 4 years of the study to 38.8% for the last 3 years (P = 0.133). When analyzing the sensitivities of MRSA and MRCNS isolates to other antibiotics, there was resistance to cefazolin and sensitivity to vancomycin in all isolates, whereas resistance to other antibiotics was variable. CONCLUSIONS There was a significant decrease in the percentage of Gram-positive microorganisms over time. The sensitivity of Gram-negative isolates to tested antimicrobials was >97% response for all the reported antibiotics; this was not the case for Gram-positive isolates, in which resistance to the antibiotics was more common. Methicillin-resistant organisms accounted for 29.1% of all Gram-positive cultures in our series, suggesting that the empiric use of vancomycin in the setting of severe suspected bacterial keratitis may be justified.

Fibrin Glue versus Sutures for attaching the Conjunctival Autograft in Pterygium Surgery: A Prospective Observer Masked Clinical Trial

Aims: To compare the degree of conjunctival autograft inflammation, subconjunctival haemorrhage (SCH) and graft stability following the use of sutures or fibrin glue (FG) during pterygium surgery. Methods: Prospective, observer masked, clinical trial. 40 eyes of 40 patients undergoing primary pterygium surgery with conjunctival autograft were allocated into two groups. Group 1 (n = 20) had FG (Tisseel) for attaching the conjunctival autograft, whereas group 2 (n = 20) had sutures. Standardised digital slit-lamp photographs were taken at 1 week, 1 month and 3 months postoperatively. Sutures were masked using commercially available photo-editing software. Two masked observers objectively graded the digital photographs for degree of inflammation, SCH and graft stability. Results: 34 of the 40 patients completed the study. When using FG, the degree of inflammation was significantly less than with sutures at 1 month (p = 0.019) and 3 months (p = 0.001) postoperatively. No significant difference was found for inflammation at 1 week postoperatively (p = 0.518). Conjunctival grafts secured with FG were as stable as those secured with sutures (p = 0.258, p = 0.076 and p = 0.624, at 1 week, 1 month and 3 months, respectively). No significant difference was found in degree of postoperative SCH between the groups (p = 0.417, p = 1 and p = 1, at 1 week, 1 month and 3 months, respectively). Conclusion: This is the first prospective clinical trial confirming that conjunctival grafts secured with FG during pterygium surgery not only are as stable as those secured with sutures, but also produce significantly less inflammation.

Topical tetracaine versus topical tetracaine plus intracameral lidocaine for cataract surgery

Purpose: To compare topical tetracaine 0.5% alone and with intracameral lidocaine 1% as a local anesthetic agent in phacoemulsification with intraocular lens (IOL) implantation. Setting: The Toronto Hospital—Western Division; Toronto, Canada. Methods: Fifty‐trine consecutive patients (60 eyes) having phacoemulsification with implantation of a foldable acrylic IOL (AcrySot) were randomized into 1 of 2 groups: The‐intracameral balanced salt solution (BSS) group received topical tetracaine 0.5% plus intracameral BSS;‐the intracameral lidocaine group received topical tetracaine 0.5.% with preservabve‐free intracameral lidocaine 1%. The patients’ subjective experience of pain, vvas measured at 4 points during surgery using a 4‐point pain scale. Patient and surgeon satisfaction with the anesthesia used was measured using a 5‐point satisfaction scale. Central endothelial cell counts were obtained preoperatively and 1 month postoperatively. Best corrected visual acuity (BCVA) was measured pfeoperatively and 1 hour, i day, 1 week, and 1 month postoperatively. Results: The mean pain score after phaccemulsfication was significantly higher in the intracameral BSS group than in the intracameral lidocaine group (0.63 ± 0.7 [SD] and 0.23 ± 0.4, respectively,‐ P < .019). The mean pain score at the end of surgery was also significantly higher in the intracameral BSS group than in the intracameral lidocaine group (0.60 ± 0.6 and 0.21 ± 0.4, respectively; P < .014). The surgeon satisfaction score was significantly lower for the intracameral BSS group than for’ the intracameral lidocaine group (3.90 1.2 and 4.73 ± 0.8, ’ respectively; P < .0007). There was no difference in patient satisfaction between the intracameral BSS and intracameral lidocaine groups (4.60 ± 0.6 and 4.70 0.8). Endothelial cell loss 1 month postoperatively was similar between the 2 groups (,6:1% ± 8% and 6.7% ± 6%) Ninety‐seven percent of patients (29/30) in each group noted BCVA improvement from preoperatively. The rate of potential visual acuity recovery was similar in both groups. Conclusion: Topical tetracaine 0.5% with intracameral lidocaine was safe and effective in patients having phacoemulsifcation with IOL implantation. The advantage of using intracameral lidocaine 1% over a placebo was a significant decrease in the patients’ subjective experience of pain and in the surgeon’s satisfaction with the anesthesia used. None of the other parameters measured in this study differed significantly between the 2 groups.