Half top hat wound configuration for penetrating keratoplasty: 1-year results.

AIMS: To compare the 1-year outcomes after half-top-hat (HTH) penetrating keratoplasty (PK) versus top-hat (TH) PK and regular PK. METHODS: We reviewed the clinical notes of 87 consecutive patients who had undergone either HTH PK (23 eyes), TH PK (36 eyes) or regular PK (35 eyes) at Toronto Western Hospital between 2002 and 2007. We evaluated best-corrected visual acuity (BCVA), topographic and refractive results, high-order ocular aberrations, endothelial cell counts and complication rates. RESULTS: The three groups of patients did not differ significantly in their demographics (age, gender and laterality), donor endothelial cell counts, preoperative visual acuity or intraocular pressure (IOP). At 12 months postoperatively, BCVA was similar in the three groups, as was the mean spherical equivalent and cylinder. The time to sutures removal was significantly shorter in the HTH PK versus regular PK groups (3.8 (1.2) vs 9.7 (1.1) months, p<0.0001), and the endothelial cell counts were significantly higher (p = 0.003). The IOP was higher in the HTH PK patients than in regular PK patients (p = 0.04). All high-order aberrations tested were significantly higher in the HTH PK than in the regular PK groups (p<0.01). Regular PK had a higher rate of astigmatism treated with relaxing incisions (n = 7 vs n = 2 in HTH PK) and dehiscence of wound incision (n = 2, versus n = 0 in HTH PK). CONCLUSIONS: BCVA and refractive results are similar after half-top-hat, top-hat and regular PK. Half-top-hat PK substantially speeds up visual recovery and contributes to significantly higher endothelial cell counts in the grafts 1 year after surgery.

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.

Femtosecond laser versus manual dissection for top hat penetrating keratoplasty.

AIM: To compare the outcomes of IntraLase-enabled top hat penetrating keratoplasty (IEK) versus retrospective results of manual top hat penetrating keratoplasty (TH-PKP) and conventional PKP. PATIENTS/METHODS: This non-randomised prospective study included 94 eyes: 23 eyes underwent IEK, 36 TH-PKP and 35 conventional PKP. Preoperative and postoperative manifest refraction, uncorrected and best-spectacle corrected visual acuity (BSCVA), high-order ocular aberrations (HOA), endothelial cell counts and complications were analysed. RESULTS: At 12 months of follow-up, the mean log MAR BSCVA was 0.32 (SD 0.31) in the IEK group, 0.53 (0.36) in the TH PKP group (p = 0.03) and 0.39 (0.30) in the conventional PKP group (p = 0.4). The mean spherical equivalent was similar between the groups and was less than -2.2 dioptres. The mean cylinder was similar in the IEK and conventional PKP group (3.6 (1.9) dioptres and 4.1 (1.8) dioptres, respectively), and was significantly lower than the TH-PKP group (5.1 (3.2) dioptres, p = 0.04). The complications rate and high-order ocular aberrations were similar between the three groups studied. The mean endothelial cell loss was significantly lower at 12 months of follow-up in the IEK and the TH-PKP groups versus conventional PKP (32.4% and 22.3% vs 40.8%, respectively) (p = 0.05). The mean time to suture removal was 4.1 (1.2) months in the IEK group and 3.9 (1.5) months in the TH-PKP group versus 9.7 (1.1) months in the conventional PKP group (p<0.0001). CONCLUSIONS: IEK is a safe and stable procedure. It results in higher endothelial counts and faster suture removal in comparison with the conventional PKP, and has less astigmatism and better BSCVA in comparison with the manual TH-PKP.

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.

Anesthesia modalities for cataract surgery.

Research articles on anesthesia modalities for cataract surgery are reviewed. A growing trend toward the use of topical anesthesia is apparent. Particular emphasis in the literature is given to determining the safety and efficacy of various forms of topical anesthesia using injectable anesthesia as a frame of reference. A consensus of opinion points toward the use of topical application of anesthetic drops plus intracameral unpreserved lidocaine 1% as the anesthesia modality that provides the best level of analgesia and comfort to patients while not compromising ocular safety. Several articles reporting complications of injectable anesthesia are also reviewed.

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-nine consecutive patients (60 eyes) having phacoemulsification with implantation of a foldable acrylic IOL (AcrySof) 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 preservative-free intracameral lidocaine 1%. The patients' subjective experience of pain was 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 preoperatively and 1 hour, 1 day, 1 week, and 1 month postoperatively. RESULTS: The mean pain score after phacoemulsification 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 phacoemulsification 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.

Establishing guidelines for the role of minor salivary gland biopsy in clinical practice for Sjögren's syndrome.

OBJECTIVE: To evaluate the predictive value of clinical variables for the finding of a positive minor salivary gland biopsy (focus score > or = 2) in patients investigated for Sjögren's syndrome (SS). METHODS: One hundred twenty-one patients with sicca symptoms were referred to a multidisciplinary SS clinic in a tertiary hospital. Each patient was evaluated on protocol and labial salivary gland (LSG) biopsy was obtained. Using the San Diego criteria as a model, patient data were subjected to a cross sectional analysis on an algorithm to determine when the LSG biopsy would be most useful for determining the diagnosis of SS in clinical practice. RESULTS: Eighty-four patients had sufficient data to be included in the study. Forty patients had LSG biopsy with focus score < 2 and 44 had focus score > or = 2. Twenty-three patients had objective evidence of sicca and positive serology according to criteria standards. Eighteen of these had a positive biopsy (78%). The remaining 5 patients had many extraglandular features suggestive of SS, and the biopsies appeared to add little practical information. Patients with incomplete criteria for sicca could be diagnosed as possible SS (3 of 4 criteria) with a positive biopsy in 14 of 18 cases. The finding of anti-Ro or anti-La positivity in patients with incomplete criteria for sicca predicted a positive LSG biopsy in 85.7% of such cases. Patients with incomplete sicca and negative anti-Ro and anti-La had a negative LSG biopsy in 82% of cases. CONCLUSION: The LSG biopsy is most necessary in patients who have partial San Diego criteria for sicca and positive anti-Ro or anti-La antibody. Where SS is not reasonably suspected, or where the diagnosis is clinically obvious, the LSG biopsy adds little useful clinical information.

Postoperative endophthalmitis: incidence, predisposing surgery, clinical course and outcome.

OBJECTIVE: To describe the predisposing surgery, clinical course and final visual outcome for patients with culture-proven and culture-negative postoperative endophthalmitis. DESIGN: Case series. SETTING: University-affiliated teaching hospital in Toronto. PATIENTS: A total of 164 patients with clinically suspected postoperative endophthalmitis admitted between January 1989 and March 1996. OUTCOME MEASURES: Type of surgery, clinical presentation, culture results, infecting organism, treatment and final visual outcome. RESULTS: An infectious agent was identified in 99 cases (60%). The organism most commonly isolated was coagulase-negative Staphylococcus (59 cases [60%]). In the culture-proven group cataract extraction was the most common predisposing surgical procedure, accounting for 85 cases (extracapsular cataract extraction [ECCE] in 60 cases and phacoemulsification in 25). The incidence rates of culture-proven endophthalmitis over the study period at our institution were 0.22% for ECCE and 0.30% for phacoemulsification. Of the 99 patients with culture-proven endophthalmitis 94 received intravitreal injections of antibiotics and 52 underwent vitrectomy. Of the 83 patients in this group for whom the final outcome was known, 29 (35%) had a visual acuity of 20/50 or better, and 15 (18%) had a vision of no light perception, with four eyes undergoing enucleation. Infection with organisms of low virulence (coagulase-negative Staphylococcus or Propionibacterium acnes) was associated with higher rates of 20/50 or better visual acuity compared with more virulent organisms (Staphylococcus aureus, streptococcal species and gram-negative bacilli) (46% vs. 10%) (p < 0.05). The culture-negative group had a significantly lower frequency of hypopyon on presentation (55% vs. 85%) and final outcome of no light perception (2% vs. 18%) (p < 0.01) than the culture-proven group. CONCLUSIONS: Endophthalmitis was most common after cataract surgery. The rates of endophthalmitis after ECCE and phacoemulsification were similar. Postoperative endophthalmitis caused by organisms other than coagulase-negative Staphylococcus or P. acnes carries a poor visual outcome.

Indications for penetrating keratoplasty in Canada, 1986-1995.

PURPOSE: To examine the leading indications for penetrating keratoplasty. METHODS: We retrospectively performed a chart review of 904 cases of penetrating keratoplasty over a 10-year period (1986-1995). Where possible, the clinical indication was corroborated by the pathological report. RESULTS: Leading indications included pseudophakic bullous keratopathy (PBK; 28.5%), regraft (22.4%), keratoconus (10.0%), Fuchs' dystrophy (7.6%), aphakic bullous keratopathy (ABK; 6.1%), herpetic keratopathy (4.2%), bacterial infection (4.2%), physical trauma (4%), interstitial keratitis (3.7%), and corneal scarring (2.8%). The most common type of intraocular lens found in patients with PBK was the anterior-chamber lens [AC IOL, 71.6%; posterior-chamber lens (PC IOL), 16%; iris-plane IOL (IP IOL; 12.5%]. In our series, we noted decreasing trends in the incidences of ABK (p < 0.001) and PBK (p < 0.04) and an increasing trend in the incidence of regraft (p < 0.0083). Our data do not show statistically significant changes in the incidences of Fuchs' dystrophy and keratoconus. Gender differences were present for Fuchs' dystrophy with female exceeding male patients by a 3:1 ratio (p < 0.001). Male exceeded female patients by 2:1 for keratoconus (p < 0.001). Male exceeded female patients by 3:1 for trauma (p < 0.001). CONCLUSIONS: In this series, the leading indications for penetrating keratoplasty were found to be generally in agreement with the data reported in recent literature. Variations may reflect the wide variations in practice and referral patterns.

Preoperative ultrasound biomicroscopy to assess ease of haptic removal before penetrating keratoplasty combined with lens exchange.

PURPOSE: To evaluate a method of assessing anterior chamber intraocular lens (IOL) haptics before combined penetrating keratoplasty and IOL exchange in eyes with poor corneal clarity resulting from pseudophakic bullous keratopathy (PBK). SETTING: Department of Ophthalmology, Toronto Hospital, Ontario, Canada. METHODS: Twelve eyes (25 haptics) with PBK were studied using ultrasound biomicroscopy (UBM). The degree of haptic encasement was graded. The result was compared with the degree of difficulty and the complications encountered in removing the IOL at the time of surgery. The surgeons were masked as to the UBM results. RESULTS: All haptics were easily visualized with UBM, with 23 in the angle and 2 passing through a peripheral iridectomy. On UBM, 9 haptics were noted to lie free in the angle, and 16 were encased by fibrotic tissue. Eight were covered by less than 100 microns and 8 by more than 100 microns of tissue. Calculations using Kappa statistics found a strong predictive value for the UBM in identifying the presence or absence of fibrotic encasement and degree of difficulty in removing the anterior chamber IOL haptics. Ultrasound biomicroscopy also allowed assessment of the adjacent angle for synechias. CONCLUSION: Ultrasound biomicroscopy provides an alternative method for evaluating anterior chamber IOL haptics when gonioscopy is not possible because of corneal opacity. This method allows the surgeon to predict preoperatively the degree of difficulty that will be encountered in explanting the IOL.

Microbial etiology and predisposing factors among patients hospitalized for corneal ulceration.

OBJECTIVE: To report the spectrum of microorganisms causing corneal ulceration in patients treated on an inpatient basis and to characterize the predisposing factors. DESIGN: Case series. SETTING: Large university-affiliated hospital in Toronto. PATIENTS: All inpatients with corneal ulcers managed between February 1991 and February 1993 (n = 95). RESULTS: Coagulase-negative staphylococci (30% of the 60 culture-positive cases), Staphylococcus aureus (23%), Streptococcus pneumoniae (12%), Pseudomonas aeruginosa (12%) and Moraxella (7%) were the predominant isolates. Previous eye surgery (cataract extraction in 30 cases [32%], penetrating keratoplasty in 12 [13%] and both procedures in 9 [9%]) was a common predisposing factor. Eleven cases (12%) were associated with the use of contact lenses, in all cases extended-wear soft contact lenses; six patients wore bandage lenses and five wore contact lenses for cosmetic reasons. Pseudomonas was the predominant isolate among contact lens wearers (four cases). Most of the 95 cases involved older patients (average age 62.5 years) with concomitant eye or systemic disease. Sixteen patients (17%) ultimately required penetrating keratoplasty. CONCLUSIONS: Recognition of the risk factors for corneal ulceration and prompt, intensive therapy are important to decrease the morbidity associated with this potentially blinding disease.

Visual acuity, refractive and keratometric results of 140 consecutive radial keratotomy procedures.

We reviewed the results of the first 140 consecutive radial keratotomy procedures (83 patients) performed by one surgeon from March 1986 to April 1992. The mean follow-up time per eye was 9.9 (standard deviation [SD] 9.1) months. The mean preoperative spherical equivalent refraction of -3.74 (SD 1.70) dioptres decreased by a mean of 2.75 D (SD 1.11 D) to a postoperative mean refraction of -0.99 D (SD 1.50 D). The postoperative uncorrected visual acuity was 20/40 or better in 120 eyes (86%). All eyes had a postoperative best corrected visual acuity of 20/40 or better. Correction to within +/- 1 D of emmetropia occurred in 98 eyes (70%), and no overcorrection of more than 1 D occurred. The mean amount of corneal flattening, as determined with keratometry, was 2.68 D (SD 1.23 D). Of the 42 eyes with high myopia (-4.50 to -9.12 D) preoperatively 57% had uncorrected vision of 20/40 or better postoperatively, and 31% had correction to within +/- 1 D of emmetropia. The corresponding figures for the 39 eyes with moderate myopia (-3.25 to -4.37 D) were 100% and 82%, and for the 59 eyes with low myopia (-1.00 to -3.12 D) 98% and 90%. There were no vision-threatening complications. The only significant loss of best corrected visual acuity occurred in one eye (1%) that lost two Snellen lines.

The effects of donor age and cause of death on corneal graft survival.

The Ontario Corneal Recipient Registry followed 299 recipients of 326 corneal transplants performed between October 1985 and October 1987. This report describes the joint effects of donor age and cause of death on subsequent graft survival in these procedures up to two years after surgery. Cox regression analysis established that grafts from donors dying of injury experienced half the risk of graft failure of those from donors dying of heart disease or other natural causes (P less than 0.05). Although donor age differed substantially between these causes of death, controlling for donor age did not alter the association. There were no statistically or clinically significant differences in graft survival associated with either donor age or recipient age. These results suggest that the health of the donor and the circumstances surrounding death may influence the quality of corneal tissue, and deserve more attention and detailed study.

Acanthamoeba keratitis with two species of Acanthamoeba.

We describe a case of Acanthamoeba keratitis related to soft contact lens wear. The patient presented with a 3-week history of severe uniocular pain, radial stromal infiltrates and subepithelial infiltrates with no epithelial defect. Acanthamoeba was cultured from the corneal biopsy specimen, contact lens and lens case. The corneal biopsy culture grew both A. castellani and A. polyphaga as well as Escherichia coli. The patient was treated with topical dibromopropamidine isethionate (Brolene) drops, neomycin and polymyxin B drops and fortified gentamicin drops. Gradual clinical improvement ensued.

Disposable contact lenses vs. contact lens maintenance for extended wear.

We compared a disposable extended wear contact lens modality with conventional extended wear over a 6-week period. To do so, we refit 31 patients who had successfully worn conventional extended wear contact lenses for more than 1 year. One eye was fit with the AcuvueR disposable contact lens, and a new extended wear lens of the type the patient had been wearing was placed on the other eye. At weekly intervals the disposable lens was discarded and a new disposable lens inserted. At the same time, the conventional lens on the fellow eye was cleaned, disinfected, and reinserted. After 6 weeks the ocular response, subjective impressions, and condition of the lenses in the two eyes were compared. Both lenses were then cultured. Three subjects had to discontinue disposable lens wear because of adverse reactions to trapped cellular debris and corneal microcysts. Although the results were not statistically significant, the Acuvue lens appeared to perform better than or equal to the conventional lens in biomicroscopic observation, visual acuity measurement, and subjective patient preference. Eighty-seven percent of patients preferred to continue with the disposable system. There were no differences found in the type or degree of microbial contamination of the lenses.

A prospective study of angiographic cystoid macular edema one year after Nd: YAG posterior capsulotomy.

We prospectively studied 120 eyes with intact opacified posterior capsules in 120 consecutive patients to determine the incidence of new late-onset angiographic cystoid macular edema (CME) after neodynium: yttrium aluminum garnet (Nd:YAG) laser posterior capsulotomy. Fifty-seven of 120 patients (48%) had both precapsulotomy and one-year post-capsulotomy angiograms done. Of these 57 patients, three eyes had angiographic CME before capsulotomy and two of these three cases had persistent CME one year after capsulotomy. In the other 54 patients, three new late-onset cases occurred (5.6%). Because the incidence of postcapsulotomy new CME was low, the statistical significance of possible risk factors, such as rupture of the anterior hyaloid face or pseudophakic status cannot be determined. However, aphakic patients with vitreous prolapse after capsulotomy tended to have a higher incidence to CME than pseudophakic patients. We recommend fluorescein angiography to identify occult CME in cases of unexplained visual-acuity decrease after capsulotomy.

Comparison of 2% hydroxypropyl methylcellulose and 1% sodium hyaluronate in implant surgery.

We conducted a prospective randomized clinical trial of 2% hydroxypropyl methylcellulose and 1% sodium hyaluronate (Healon) in routine extracapsular cataract surgery with implantation of a posterior chamber intraocular lens. Of the 84 patients 40 received methylcellulose and 44 received sodium hyaluronate. There was no statistically significant difference in endothelial-cell loss or induced cellular polymegathism between the two groups. The intraocular pressure before and after surgery was similar in the two groups, as was the visual acuity 8 weeks after surgery. The results suggest that 2% hydroxypropyl methylcellulose is a safe and effective alternative to 1% sodium hyaluronate in routine implant surgery.