Wound temperature profiles of coaxial mini-incision versus sleeveless microincision phacoemulsification.

BACKGROUND: Temperature profiles at the corneal wound of coaxial mini-incision (2.4 mm) cataract surgery and sleeveless microincision (1.1 mm) cataract surgery were compared. DESIGN: Prospective, controlled, paired-eye clinical trial conducted in a tertiary care hospital. PARTICIPANTS: Twenty patients with mild-to-moderate bilateral nuclear sclerotic cataract. METHODS: Twenty patients underwent bilateral cataract surgery within a 1-month period. One eye was operated on by conventional coaxial mini-incision (2.4 mm) phacoemulsification. The second eye underwent microincision surgery by using a naked phacoemulsification tip and a specialized 19-gauge anterior chamber maintainer as the sole fluid source (three-port microincision cataract surgery technique). Patients had moderate bilateral cataracts with no other anterior segment pathology. Temperature at the corneal wound was constantly recorded by using infrared thermal imaging. MAIN OUTCOME MEASURES: Temperatures at the corneal wound. RESULTS: Mean temperatures at the corneal surgical wound were not significantly different between the coaxial and sleeveless groups (31.1 °C ± 2.3 vs. 31.0 °C ± 2. 0; P = 0.89). There was also no difference in maximum temperatures reached during phaco-emulsification. Temperatures did not rise above 40 °C during any surgery, and there were no corneal burns. Final visual acuity and intraoperative and postoperative complication rates were similar between the two groups. CONCLUSIONS: The temperature profile at the surgical wound using a microincisional sleeveless phacoemulsification technique is comparable with that of the conventional coaxial mini-incision method.

Prediction of refractive outcomes with toric intraocular lens implantation.

PURPOSE: To evaluate and compare the accuracy of different methods to measure and predict postoperative astigmatism with toric intraocular lens (IOL) implantation. SETTING: Ein-Tal Ophthalmology Center, Tel-Aviv, Israel. DESIGN: Retrospective case series. METHODS: Postoperative corneal astigmatism was measured with 3 devices (IOLMaster 500; optical low-coherence reflectometry [OLCR]-based Lenstar LS 900; Atlas topographer) and compared with the manifest astigmatic refractive outcome in patients with toric IOLs. The error in the predicted residual astigmatism was calculated by vector analysis according to the measurement and calculation method used to predict the required toric IOL cylinder power. RESULTS: The centroid errors in predicted residual astigmatism were against the rule with the Alcon and Holladay toric calculators (0.53 to 0.56 diopter [D]), were lower with the Baylor nomogram (0.21 to 0.26 D), and were lowest for the Barrett toric calculator (0.01 to 0.16 D) (P <.001). The Barrett toric calculator had the lowest median absolute error in predicted residual astigmatism (0.35 to 0.54 D, all devices) compared with the Alcon and Holladay toric calculators with or without the Baylor nomogram (P <.021). The Barrett toric calculator and the OLCR device achieved the most accurate results; 75.0% and 97.1% of eyes were within ±0.50 D and ±0.75 D of the predicted residual astigmatism, respectively. CONCLUSION: Prediction of astigmatic outcomes with toric IOLs can be improved with appropriate measuring devices and methods to establish the required toric IOL power.

Bilateral Sequential NAION following Cataract Extraction: Case Report and Review of the Literature.

We report a 64-year-old patient who developed nonarteritic ischemic optic neuropathy (NAION) in both eyes following cataract extraction. The cataract surgeries in both eyes were uneventful and performed within a year, and NAION occurred a few months postoperatively in both eyes. A review of the literature on this rare complication is provided. This case report serves to raise awareness among cataract surgeons about this potential complication associated with irreversible visual loss, and especially about its high risk of bilaterality.

Simulation of neodymium:YAG posterior capsulotomy for ophthalmologists in training.

UNLABELLED: We describe a new method for training ophthalmologists to perform a neodymium:YAG (Nd:YAG) posterior capsulotomy. Our model consists of an artificial anterior chamber that can be adjusted to fit any laser instrument and houses an intraocular lens (IOL). The posterior surface of the IOL is coated with a crust simulating posterior capsule opacification (PCO). This model PCO reacts similarly to real PCO when the Nd:YAG laser is applied to it. It creates conditions simulating near-real posterior capsulotomy and has been used successfully to train 3 novice residents who had not performed the procedure. The model is simple, reusable, and inexpensive. We believe it may be a valuable tool in training ophthalmologists to perform an Nd:YAG posterior capsulotomy. FINANCIAL DISCLOSURE: Neither author has a financial or proprietary interest in any material or method mentioned.

Temperature profiles of sleeveless and coaxial phacoemulsification.

PURPOSE: To study the temperature profile at the corneal wound during 2 sleeveless techniques versus 2 coaxial phacoemulsification techniques. SETTING: Department of Ophthalmology, Meir Medical Center, Kfar Saba and Ein-Tal Eye Center, Tel-Aviv, Israel. DESIGN: Experimental study. METHODS: Thirty-six porcine eyes were randomized into 4 groups: Group 1: conventional coaxial system (3.0 mm incision); Group 2: coaxial microincision cataract surgery (MICS) system (2.2 mm incision); Group 3: bimanual MICS (1.1 mm incision); Group 4: sleeveless tri-MICS (1.1 mm incision) using a 19-gauge anterior chamber maintainer as the sole fluid source. Temperature measurements were taken using a thermocouple and an infrared thermal imaging system. Measurements were taken in 2 settings; that is, with and without occlusion. RESULTS: With no occlusion, corneal burns did not occur in any group. However, corneal temperatures were lower with the sleeveless systems (Groups 3 and 4) than with the coaxial systems (Groups 1 and 2) (P=.0003). When occlusion was induced, temperatures were kept constantly low in the sleeveless groups, whereas in the coaxial groups, temperatures increased rapidly, causing corneal burns within seconds. The mean temperature elevations at the incision sites were 39 °C, 48.5 °C, 13.6 °C, and 11.3 °C in Groups 1, 2, 3, and 4, respectively (P<.0001). CONCLUSIONS: Sleeveless phacoemulsification maintained lower tissue temperatures than sleeved coaxial methods. During occlusion, fluid flow around the naked tip of the sleeveless systems prevented heat accumulation and corneal burns.

Acute calcific band keratopathy: case report and literature review.

UNLABELLED: An 86-year-old patient developed a significant intraocular inflammatory reaction after having phacoemulsification. Topical therapy did not eliminate the inflammation, and tissue plasminogen activator (tPA) was injected into the anterior chamber. A white corneal plaque appeared in the previously clear cornea within days of the injection. The lesion was diagnosed as calcific band keratopathy and successfully treated with ethylenediaminetetraacetic acid chelation. Electron microscopy and elemental analysis of a corneal scraping from the lesion established its composition to be mainly calcium and phosphate, validating the diagnosis. This is the seventh reported case of rapid formation of calcific band keratopathy after tPA injection. The pathogenesis of this rare complication involves multiple factors, including alkalinization of the intraocular pH, increased phosphate concentration, and endothelial dysfunction. FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned.

Outcome of iris fixation of subluxated intraocular lenses.

BACKGROUND: The aim of this study was to evaluate the efficacy of iris fixation of subluxated intraocular lenses (IOLs). METHODS: A retrospective study of 44 consecutive cases of subluxated IOLs that underwent iris fixation of the IOL. Demographic information, data regarding surgery, and follow-up were retrieved from patient files. All eyes were operated on in a similar fashion by the same anterior segment surgeon (A.M.) utilizing the McCannel suture technique and/or the Siepser slipknot technique. The main outcome measures were visual acuity improvement, surgically induced astigmatism, and assessment of complications. RESULTS: Ten eyes had a documented complication during primary cataract extraction. Pseudoexfoliation was present in 11 eyes (25 %). History of ocular trauma and high myopia were present in six eyes (each). Excluding eyes with macular disease and very low visual acuity, visual acuity improved from 0.4 (± 0.05) logMAR to 0.24 (± 0.05) logMAR (p = 0.047). Eyes with low pre-operative astigmatism did not worsen post-operatively (R square linear = 0.8, p < 0.01). Pupil ovalization was a major aesthetic complication (21 of 44 eyes). Major hemorrhagic complications were uncommon. One patient developed intermediate uveitis 1 year after IOL fixation. CONCLUSIONS: In this study of 44 eyes, iris fixation was proven to be a an effective method for treating subluxated IOLs.

Cataract surgery in megalocornea Comparison of 2 surgical approaches in a single patient.

We describe the outcome of cataract surgery in both eyes of a patient with megalocornea. Phacoemulsification through a scleral tunnel resulted in wound leak; the clear corneal incision was more stable. Using conventional IOL power calculation may result in significant hyperopia.

Capsule anchor to manage subluxated lenses: initial clinical experience.

PURPOSE: To evaluate the use of a capsule anchor to reposition and fixate the capsular bag to the scleral wall in eyes with subluxation of the crystalline lens. SETTING: Department of Ophthalmology, Meir Medical Center, Kfar-Saba, Israel. METHODS: This study evaluated a 1-plane poly(methyl methacrylate) intraocular implant (Capsular Anchor) that is clipped to the anterior capsule to support it. The device is composed of a central rod located in front of the anterior capsule and 2 lateral arms positioned behind the anterior capsule. The anchor is secured to the sclera with a single 9-0 or 10-0 polypropylene suture. A capsular tension ring (CTR) can be implanted in conjunction with the anchor. The anchor was implanted in eyes with subluxated cataractous lenses. After surgery, intraocular lens (IOL) centration and corrected distance visual acuity (CDVA) were monitored for 12 months. RESULTS: The anchor was successfully implanted in 2 patients with traumatic subluxated lenses and 2 patients with Marfan syndrome. In 1 eye, 2 anchors were used because of zonular dehiscence that extended during surgery. In 3 eyes, an IOL was implanted in the bag and in 1 eye, in the sulcus. A CTR was additionally implanted in 3 eyes. During the 12-month follow-up, the IOLs remained well centered and stable. The CDVA improved to 20/20 to 20/25 in all cases. CONCLUSION: The capsule anchor was effective in fixating the lens capsule to the scleral wall in cases of significant zonular dehiscence.

Measurements of intraocular pressure by Goldmann tonometry, Tonopen XL, and the transpalpebral tonometer, TGDc-01, after penetrating keratoplasty: a comparativye study.

PURPOSE: The aim of this study was to compare intraocular pressure (IOP) measurements obtained by Goldmann tonometry (GT), the Tonopen XL, and a new transpalpebral tonometer, TGDc-01, in eyes that had undergone penetrating keratoplasty (PKP). METHODS: IOP was measured in post-PKP eyes by means of GT, Tonopen XL, and TGDc-01. Central corneal thickness measurements were also obtained for all eyes. RESULTS: Forty-five eyes of 43 patients were enrolled in the study. The mean IOP difference (+/-SD) was -0.42 +/- 5.83 mm Hg between GT and Tonopen and 3.20 +/- 7.55 mm Hg between GT and TGDc-01. The correlation coefficient was 0.84 between GT and Tonopen XL (P < 0.001) and 0.71 between GT and TGDc-01 (P < 0.001). Overall 2-way analysis of variance between the means showed no significant differences between the 3 devices (P = 0.077). CONCLUSION: A closer agreement was found between GT and Tonopen XL in post-PKP eyes. TGDc-01 yielded lower IOP readings than the other 2 devices. It remains uncertain whether this new transpalpebral tonometer is simply inaccurate or whether avoiding contact with the corneal graft by measuring IOP through the eyelid enables it to provide more accurate IOP readings than those obtained by transcorneal techniques.

Late-onset laser in situ keratomileusis-related corneal ulcer--a case series.

PURPOSE: To report 4 cases of flap margin-related corneal ulcer that developed 5 years after laser in situ keratomileusis (LASIK) procedures. METHODS: We retrospectively documented the clinical and laboratory characteristics of all patients between 2004 and 2008 who presented with LASIK-related corneal ulcer that appeared >5 years postoperatively. The 4 patients who had this condition were 25-, 33-, 61-, and 62-year-old males. RESULTS: Two patients had cultures positive to Staphylococcus aureus and Streptococcus epidermidis. Two ulcers healed after standard fortified topical antibiotic regimen, 1 ulcer healed after treatment with moxifloxacin, and the fourth healed after treatment with lomefloxacin. All cases presented 5 years after the LASIK procedure. CONCLUSIONS: LASIK procedures can be associated with the risk of corneal infection even years later. The mechanism may be flap margin instability causing epithelial defense barrier disturbance.

Pressure phosphene tonometry versus Goldmann applanation tonometry for measuring intraocular pressure before and after LASIK.

PURPOSE: To compare pressure phosphene tonometry with Goldmann applanation tonometry for measuring intraocular pressure (IOP) before and after LASIK. METHODS: Forty-three (18 men and 25 women) consecutive healthy patients underwent complete pre- and postoperative LASIK ophthalmologic assessments including manifest and cycloplegic refraction, keratometry, and central corneal thickness. Three repetitive sets of pressure phosphene tonometry and Goldmann applanation tonometry measurements were performed the day before and 3 months following uneventful LASIK. RESULTS: Mean preoperative spherical equivalent refraction was -4.70 +/- 2.50 diopters (D) (range: -1.50 to -12.90 D) and mean preoperative keratometry was 43.95 +/- 1.08 D. After LASIK, spherical equivalent refraction was +0.23 +/- 0.11 D and mean keratometry was 39.46 +/- 2.28 D. Preoperative pressure phosphene tonometry (12.16 +/- 1.58 mmHg) and Goldmann applanation tonometry (12.01 +/- 1.55 mmHg) IOP measurements were similar. Postoperative IOP was 10.30 +/- 1.16 mmHg with Goldmann applanation tonometry and 12.20 +/- 1.62 mmHg with pressure phosphene tonometry. The postoperative IOP difference between Goldmann applanation tonometry and pressure phosphene tonometry was 0.15 +/- 1.12 mmHg (P = .41). The mean change in pachymetry after LASIK was 68.73 +/- 73 microm. The change in Goldmann applanation between preoperative and postoperative LASIK values was 1.71 +/- 1.43 mmHg (P < .0001), a change that was strongly correlated with changes in corneal thickness (R = 0.75, P < .0001) and keratometry (R = 0.72, P < .0001). No such correlations were found with pressure phosphene tonometry. CONCLUSIONS: Goldmann applanation tonometry-measured IOP decrease after LASIK is strongly correlated with a decrease in central corneal thickness and changes in keratometry, whereas pressure phosphene tonometry-measured IOP is independent of corneal thickness. Pressure phosphene tonometry appears to be a more reliable method for recording tonometry in these patients.

Repositioning and scleral fixation of the subluxated lens capsule using an intraocular anchoring device in experimental models.

PURPOSE: To describe a new device for repositioning and scleral fixation of the capsular bag of subluxated lenses in experimental models. SETTING: Laboratory for Experimental Microsurgery, Meir Medical Center, Kfar-Saba, Israel. METHODS: The capsular anchoring device is a poly(methyl methacrylate) 1-plane implant consisting of 2 handles that grasp the edges of the capsulorhexis and a base for scleral fixation with a single 10-0 or 9-0 polypropylene suture. A temporary safety suture can be used to facilitate manipulations and prevent loss of the device through the zonular defect until it is secured to the scleral wall. The device was implanted in porcine eyes and living rabbit eyes. An animal model of lens subluxation was achieved by tearing about one third of the zonules. Capsule centration, implant stability, and inflammatory reaction were evaluated 2 to 4 weeks after implantation in the living model. RESULTS: The device was implanted in 7 porcine eyes and 9 living rabbit eyes. A lens subluxation model was created in 4 porcine eyes and 2 rabbit eyes. The device effectively pulled the capsular bag to the center and remained stable up to 4 weeks thereafter. Very large zonular dialysis (>5 hours) was managed using 2 devices. Successful intraocular lens implantation was done repeatedly in the presence of the device. The implant was well tolerated in all rabbit eyes. Histopathological examination of the enucleated eyes revealed no inflammatory reaction or adhesions. The margin of the anterior capsulorhexis remained intact in all cases. CONCLUSIONS: Experimental studies of a capsular anchoring device for subluxated lenses confirmed the safety and efficacy of the new device. A capsular tension ring can also be inserted separately to further stabilize the capsular bag.

Hydrostatic pressure as an office procedure for congenital nasolacrimal duct obstruction.

BACKGROUND: The estimated incidence of congenital nasolacrimal duct obstruction (CNDO) is 5% to 20%. We examined our success rate of treating CNDO with hydrostatic pressure (the Crigler method) as an office procedure. METHODS: A total of 742 children with CNDO initially were treated noninvasively with hydrostatic pressure. The procedure was safely repeated up to 3 times, with an interval of at least 1 week, if the condition persisted. RESULTS: Success was defined as no epiphora or discharge. The success rate for the entire study group was 45% for children up to 1 year of age. The ducts were opened in 46% (343/742) at the first attempt of hydrostatic pressure, in 35% (42/120) at the second attempt, and in 38% (8/21) at the third attempt. When the maneuver was performed in patients younger than 2 months of age, the success rate of the first attempt was 56%, decreasing to 46% in children 2 to 6 months of age and to 28% older than 6 months of age. CONCLUSIONS: Hydrostatic pressure is an effective way of resolving infant CNDO and shortening the duration of the associated morbidity. The success rate is higher when the procedure is conducted in patients up to 2 months of age. Nevertheless, we recommend this approach for every infant presenting with CNDO at the first office visit, even after 6 months of age. Procedures can be repeated safely and successfully.

[Corneal changes after phacoemulsification with a corneal versus a scleral tunnel incision].

AIM: To compare central corneal thickness and endothelial cell loss after phacoemulsification with clear cornea and scleral tunnel incisions. SETTING: Ophthalmology Department, Toronto Western Hospital, University of Toronto, Toronto, Ontario, Canada. METHOD: Fifty-one eyes of 51 patients were randomly assigned to one of the two study groups. All patients had central corneal thickness measured preoperatively and on post-op days 1, 7, 30 and 90. Specular microscopy was performed preoperatively and at 3 months after surgery. RESULTS: Cumulative mean central endothelial cell count before surgery was 2,355 +/- 360 mm2 and 2,305 +/- 376 mm2 post-op. Mean percentage cell loss was 0.82% +/- 19.7%. For the scleral tunnel group it was 1.8% +/- 21.5%, and for the clear cornea group 0.13% +/- 18.3% (p>0.05). Two-way ANOVA demonstrated no effect of type of incision and surgeon on the endothelial cell loss. Pearson correlation coefficients between phaco power and cell loss calculated for each of the incisions and for each of the surgeons was not significant. Corneal thickness increased significantly in all measurements post-op, and returned to baseline by 3 months. There was no difference in the pachymetry change between the two study groups. CONCLUSIONS: Clear cornea and scleral tunnel incisions seem to result in no significant difference in endothelial cell loss and or central corneal thickness at 3 months post-op.

Corneal transplants for the treatment of congenital corneal opacities.

PURPOSE: To describe the results of corneal transplants in infants and young children with congenital corneal disorders. METHODS: The charts of 38 children who underwent corneal transplantation for congenital corneal opacities from 1988 to 1999 at the Hospital for Sick Children, Toronto, Ontario, were reviewed. Parameters reviewed included indication, age at diagnosis and surgery, graft size, graft clarity, repeat surgery, glaucoma pre- and postsurgery, visual acuity, and refraction. RESULTS: Thirty-eight children (63 eyes) underwent 86 corneal transplants. The four most common indications for surgery included posterior polymorphous dystrophy, Peters anomaly, congenital glaucoma, and sclerocornea. Mean follow-up was 40.4 +/- 30.2 months (range, 2-111 months). Seventy-eight percent of the grafts were clear at the final follow-up visit. There were 23 repeat grafts in the entire group. CONCLUSIONS: The overall success rate of graft clarity was 78% for children undergoing corneal transplantation for congenitally opaque corneas. Best results were achieved in patients with posterior polymorphous dystrophy, followed by patients with Peters anomaly. Sclerocornea and congenital glaucoma carried a 50% chance of success, with repeated transplants needed for many of the eyes.

Scleral and iris fixation of posterior chamber lenses in the absence of capsular support.

PURPOSE OF REVIEW: To review the methods described in the literature in the past year (from August 2003 to date). RECENT FINDINGS: Techniques for scleral and iris suturing have proven safe and effective to fixate posterior chamber intraocular lenses and avoid the sight-threatening complications of anterior chamber lenses. SUMMARY: Scleral and iris fixation have both become well-established effective means for stabilizing posterior chamber lenses in the lack of adequate capsular support.

Effect of laser in situ keratomileusis on tear secretion and corneal sensitivity.

PURPOSE: To study changes in corneal sensitivity and Schirmer I scores following laser in situ keratomileusis (LASIK) and the correlation between the two. METHODS: Twenty-three patients who had LASIK at The Gimbel Eye Center, Toronto, Ontario, Canada, participated in the study. All were asymptomatic for severe dry eyes before surgery. All patients underwent a Schirmer test (without anesthetic), a filament corneal sensitivity test, and slit-lamp microscopy including staining with lissamine green preoperatively and at postoperative time intervals of 3 to 5 days, and 1 and 3 months. RESULTS: No correlation was found between the difference in Schirmer test scores and the difference in corneal sensitivity, at any timepoint. A non-statistically significant trend toward a reduction in Schirmer values immediately after surgery was noted, with a return to slightly lower than baseline levels by 3 months. Corneal sensitivity was significantly decreased immediately after surgery and returned to preoperative levels by 3 months (P<.0001). There was a statistically significant effect of age, gender, and mean spherical equivalent refraction on corneal sensitivity (P<.0001) and a significant effect of age on the time trend (P=.02), but not for Schirmer levels or staining. CONCLUSIONS: A significant reduction in corneal sensitivity immediately following surgery occurred, with a return to preoperative levels by 3 months. Schirmer test scores similarly decreased, although without statistical significance, and returned to near preoperative levels after 3 months. A statistically significant correlation between the reduction in tearing and reduction in corneal sensitivity after LASIK was not demonstrated.