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Purpose: To determine the relationship between the achieved refractive change and the change in simulated keratometry (K) after myopic laser situ keratomileusis (LASIK) and compare this relationship between custom and conventional treatments. Setting: Department of Ophthalmology, University of California, Davis, Sacramento, California, and John A. Moran Eye Center, Salt Lake City, Utah, USA. Methods: The change in simulated K and the refractive change induced by custom myopic LASIK and conventional LASIK were determined. The relationship between the variables was analyzed by regression methods. Results: Custom treatment was performed in 106 eyes and conventional treatment in 224 eyes. Simple linear regression analysis did not fit the clinical observation when the refractive change was less than 2.00 diopters (D) of myopic correction with both treatments. Under the linear model and nonlinear model, each unit of refractive change yielded a greater change in corneal topographic power with custom treatment than with conventional treatment. With both treatments, the rate of change in simulated K was not constant and was much more variable with lower amounts of correction. The relationship was more constant and linear with larger amounts of refractive correction. Conclusions: The relationship between the measured change in simulated K and the induced refractive change better fit a nonlinear relationship with smaller amounts of refractive correction in custom LASIK and conventional LASIK. Under all forms of analysis, custom treatments yielded a greater per-unit change in corneal curvature than conventional treatments, especially for refractive corrections of 4.00 D and higher. Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned. [ABSTRACT FROM AUTHOR]

Cataract surgery after corneal refractive surgery can be challenging for the ocular surgeon due to the difficulty with accurate intraocular lens (IOL) power determination and unexpected refractive surprises. As clinicians have done more work, a number of error sources have been determined. Furthermore, an increasing number of methods to avoid these refractive surprises have been proposed. The combination of this work has resulted in recommendations for the modification of standard IOL power calculations to improve outcomes. The following article includes a brief on, and by no means, inclusive, error sources and ways to compensate for them. [ABSTRACT FROM AUTHOR]

Objective: To estimate the rate of acute postoperative endophthalmitis after uncomplicated cataract surgery in patients treated before and after surgery with 1 of 2 different fourth-generation fluoroquinolone ophthalmic drops for surgical prophylaxis. Design: Retrospective, multicenter, observational case series. Participants: Included in this study were 20 013 patients from 9 cataract surgery centers in 7 states in the United States. Methods: Patients who had undergone uncomplicated phacoemulsification who received preoperative and postoperative topical fourth-generation fluoroquinolones for surgical prophylaxis between March 2003 and July 2005 were included in the study. The files of patients in whom acute endophthalmitis developed were reviewed and analyzed. Main Outcome Measures: Number and rate of endophthalmitis cases after uncomplicated cataract surgery. Results: During the study period, the participating surgeons performed 20 013 uncomplicated surgeries. Of these, 16 209 patients (81%) received topical gatifloxacin and 3804 patients (19%) were treated with topical moxifloxacin as antiinfective prophylaxis. A total of 14 patients experienced endophthalmitis. The overall rate of endophthalmitis was 0.07%. There were 9 endophthalmitis patients in the gatifloxacin group and 5 endophthalmitis patients in the moxifloxacin group. The rate of endophthalmitis in the gatifloxacin group was 0.06% and the rate in the moxifloxacin group was 0.1%. The difference in the rate of endophthalmitis between the 2 groups was not statistically significant. In 10 of the patients, vitreous culture results were positive. Coagulase-negative staphylococci, followed by streptococci, species were the most commonly isolated organisms in the culture-positive patients. Conclusions: The overall rate of endophthalmitis after uncomplicated cataract surgery in patients treated with topical fourth-generation fluoroquinolones as antiinfective prophylaxis was 0.07%. This rate was within the range of previously reported rates of endophthalmitis in the literature. The difference in the observed rate of postoperative endophthalmitis in patients treated with moxifloxacin versus gatifloxacin was not statistically significant. [Copyright &y& Elsevier]

Purpose: To report 1-year results of laser in situ keratomileusis (LASIK) in 7 eyes with corneal endothelial guttata and a family history of Fuchs'' endothelial dystrophy. Setting: John Moran Eye Center, University of Utah, Salt Lake City, Utah, USA. Methods: A retrospective chart review was performed of 4 patients (7 eyes) who had trace to 1+endothelial guttata and a family history of Fuchs dystrophy and then had uneventful LASIK for the correction of myopia and myopic astigmatism. Preoperative and postoperative measurements included uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), corneal pachymetry, endothelial cell density (ECD), manifest refraction, and spherical equivalent. The changes in ECD, pachymetry, and spherical equivalent after LASIK were subjected to statistical analysis using a paired Student t test to determine significance. Results: Transient corneal edema was noted in the early postoperative period in 3 eyes of 2 patients. At 1 year, 6 of the 7 (86%) eyes had lost ≥2 lines of BSCVA. A statistically significant decrease in ECD of 12.4% ± 2.7% was observed at 1 year compared with baseline (P<.001). An increase in corneal thickness (P = .006) and a statistically significant myopic shift in spherical equivalent (P = .017) was also noted at 1 year compared with 3 months. Conclusions: Patients with mild corneal guttata and a family history of Fuchs'' dystrophy are prone to transient corneal edema, loss of BSCVA, endothelial cell loss, and myopic regression after uneventful LASIK for correction of myopia and myopic astigmatism. [Copyright &y& Elsevier]

Purpose: (1) To evaluate the accuracy of nomogram-based adjustment of intraocular lens (IOL) power to achieve a desired refractive target after cataract surgery in postmyopic LASIK and photorefractive keratectomy (PRK) eyes and (2) to compare the accuracy of the nomogram-based method with the clinical history method. Design: Multicenter, retrospective, interventional, noncomparative case series. Subjects: Fourteen patients (19 eyes) after myopic LASIK or PRK with visually significant cataracts. Intervention: All eyes underwent cataract extraction and posterior chamber intraocular lens implantation. In each case, IOL power was determined with standard keratometry and biometry. Power adjustment was made by use of a theoretical nomogram followed by implantation. Main Outcome Measures: (1) Final refraction and spherical equivalent after cataract surgery and (2) deviation of the final spherical equivalent from the refractive target. Results: After cataract extraction, by use of nomogram adjustment, 63.2% of eyes were within 0.5 D of the intended spherical equivalent, 84.2% were within 1.0 diopter of the intended spherical equivalent, and 100% were within 1.5 D of the intended spherical equivalent. The clinical history method was accurate in predicting the correct IOL power in 37.5% of cases, regardless of whether spectacle or corneal plane refraction was used. Conclusions: (1) Given the change in spherical equivalent induced by myopic LASIK/PRK, IOL power can be adjusted accurately to avoid undercorrection without the need for the prerefractive surgery corneal power. (2) The nomogram-based method was more accurate than the clinical history method. [Copyright &y& Elsevier]

Purpose: To retrospectively review the occurrence, treatment, and visual outcomes associated with various etiologies of keratitis as a postoperative complication of laser in situ keratomileusis (LASIK) at an academic surgical center. Setting: John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA. Methods: The charts of 5618 post-LASIK patients (10 477 eyes) were reviewed for the development of keratitis. Occurrence rates, management regimens, and final best spectacle-corrected visual acuity (BSCVA) were reported for infectious and noninfectious keratitis etiologies. Results: Post-LASIK keratitis was diagnosed in 279 eyes. The keratitis was diagnosed as infectious in 33 eyes (12%) and as noninfectious in 246 eyes (88%). Infectious cases included 5 eyes (15%) with herpes simplex keratitis (HSV), 18 (55%) with adenoviral keratitis, and 10 (30%) with nonviral (including bacterial, fungal, and parasitic) keratitis. Of noninfectious cases, 193 (78%) were classified as diffuse lamellar keratitis (DLK), 36 (15%) as staphylococcal marginal hypersensitivity, and 17 (15%) as localized debris-related keratitis. Conclusions: The occurrence of post-LASIK keratitis was 2.66%, with DLK being the most common diagnosis overall. The occurrence of noninfectious keratitis (2.34%) was 7.5 times greater than the occurrence of infectious keratitis (0.31%). Adenoviral keratitis had the best visual outcomes overall, with all 18 patients achieving 20/20 BSCVA. In contrast, all 5 eyes with HSV keratitis lost 1 or 2 lines of BSCVA. Excluding adenoviral keratitis, infectious etiologies had significantly worse visual outcomes than noninfectious etiologies at the 20/40 and 20/20 levels (P = .0013 and P<.001, respectively). [Copyright &y& Elsevier]

We report the first 2 cases of bacterial keratitis resistant to fourth-generation fluoroquinolones after laser in situ keratomileusis (LASIK) and photorefractive keratectomy (PRK). The first patient had Pseudomonas aeruginosa keratitis after PRK despite treatment with moxifloxacin. The second patient was on gatifloxacin post-LASIK when she had methicillin-resistant Staphylococcus aureus (MRSA) keratitis diagnosed. In both cases, culture susceptibilities showed isolates resistant to moxifloxacin and gatifloxacin, and treatment with topical aminoglycosides and surgical intervention was necessary to effect a cure. These cases show the potential limitations in the coverage of these antibiotics. [Copyright &y& Elsevier]

Purpose: To compare the incidence of flap complications after creation of laser in situ keratomileusis (LASIK) flaps using a zero-compression microkeratome or a femtosecond laser. Setting: John A. Moran Eye Center, Department of Ophthalmology, University of Utah, Salt Lake City, Utah, USA. Design: Evidence-based manuscript. Methods: The flap complication rate was evaluated during the initial 18 months of experience using a zero-compression microkeratome (Hansatome) or a femtosecond laser (IntraLase FS60) for flap creation. Results: The flap complication rate was 14.2% in the microkeratome group and 15.2% in the femtosecond laser group (P = .5437). The intraoperative flap complication rate was 5.3% and 2.9%, respectively (P = .0111), and the postoperative flap complication rate, 8.9% and 12.3%, respectively (P = .0201). The most common intraoperative complication in the microkeratome group was major epithelial defect/sloughing; the rate (2.6%) was statistically significantly higher than in the femtosecond laser group (P = .0006). The most common postoperative complication in both groups was diffuse lamellar keratitis (DLK) (6.0%, microkeratome; 10.6%, femtosecond laser) (P = .0002). Conclusion: Although the total complication rates between the 2 groups were similar, the microkeratome group had significantly more epithelial defects intraoperatively and the femtosecond laser group had significantly more DLK cases postoperatively. Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned. [ABSTRACT FROM AUTHOR]