Combined astigmatic keratotomy and conductive keratoplasty to correct high corneal astigmatism.

PURPOSE: To determine the safety, efficacy, and predictability of combined astigmatic keratotomy (AK) and conductive keratoplasty (CK) for treating high corneal astigmatism. SETTING: University of California-Los Angeles, Los Angeles, California, USA. DESIGN: Retrospective case series. METHODS: From January 1, 2004, to December 31, 2009, AK and CK were performed in eyes with corneal astigmatism of 5.0 diopters (D) or more after keratoplasty or trauma. The uncorrected (UDVA) and corrected (CDVA) distance visual acuities, spherical equivalent (SE), defocus equivalent, mean astigmatism, efficacy index, and complications were evaluated. RESULTS: In 11 eyes of 11 patients, the mean UDVA improved from 1.54 logMAR ± 0.50 (SD) preoperatively to 0.69 ± 0.62 logMAR 3 months postoperatively (P < .001) and the mean CDVA from 0.55 ± 0.62 logMAR to 0.12 ± 0.11 logMAR (P = .028). The mean SE and mean defocus equivalent decreased from -1.25 ± 5.06 D to 3.13 ± 3.06 D (P = .15) and from 7.98 ± 4.41 D to 6.97 ± 3.73 D (P = .45), respectively; these changes were not statistically significant. The mean absolute astigmatism decreased from 10.25 ± 4.71 D to 4.31 ± 2.34 D (P < .001). The mean absolute orthogonal and mean oblique astigmatism showed a statistically significant decrease. The efficacy index was 0.82. One case of wound gape after AK required suturing. No infectious keratitis, corneal perforation, or graft rejection occurred. CONCLUSIONS: Results indicate that combined AK and CK is safe and effective for correcting high corneal astigmatism after surgery or trauma.

Effect of posterior corneal astigmatism on refractive outcomes after toric intraocular lens implantation.

PURPOSE: To compare the prediction error after toric intraocular lens (IOL) (Acrysof IQ) implantation using corneal astigmatism measurements obtained with an IOLMaster automated keratometer and a Galilei dual rotating camera Scheimpflug-Placido tomographer. SETTING: Jules Stein Eye Institute, University of California Los Angeles, Los Angeles, California, USA. DESIGN: Retrospective case series. METHODS: The predicted residual astigmatism after toric IOL implantation was calculated using preoperative astigmatism values from an automated keratometer and the total corneal power (TCP) determined by ray tracing through the measured anterior and posterior corneal surfaces using dual Scheimpflug-Placido tomography. The prediction error was calculated as the difference between the predicted astigmatism and the manifest astigmatism at least 1 month postoperatively. The calculations included vector analysis. RESULTS: The study evaluated 35 eyes (35 patients). The preoperative corneal posterior astigmatism mean magnitude was 0.33 diopter (D) ± 0.16 (SD) (vector mean 0.23 × 176). Twenty-six eyes (74.3%) had with-the-rule (WTR) posterior astigmatism. The postoperative manifest refractive astigmatism mean magnitude was 0.38 ± 0.18 D (vector mean 0.26 × 171). There was no statistically significant difference in the mean magnitude prediction error between the automated keratometer and TCP techniques. However, the automated keratometer method tended to overcorrect WTR astigmatism and undercorrect against-the-rule (ATR) astigmatism. The TCP technique lacked these biases. CONCLUSIONS: The automated keratometer and TCP methods for estimating the magnitude of corneal astigmatism gave similar results. However, the automated keratometer method tended to overcorrect WTR astigmatism and undercorrect ATR astigmatism. FINANCIAL DISCLOSURE: Dr. Hamilton has received honoraria for educational lectures from Ziemer Ophthalmic Systems. No other author has a financial or proprietary interest in any material or method mentioned.

Effect of mitomycin-C on the variance in refractive outcomes after photorefractive keratectomy.

PURPOSE: To compare the variance in manifest refraction spherical equivalent (MRSE) after photorefractive keratectomy (PRK) with mitomycin-C (MMC), PRK without MMC, and laser in situ keratomileusis (LASIK) for the treatment of myopic astigmatism. SETTING: Jules Stein Eye Institute, University of California, Los Angeles, Los Angeles, California, USA. DESIGN: Retrospective case series. METHODS: Patients were classified into 3 groups of preoperative refraction-matched eyes as follows: PRK with MMC 0.02%, PRK without MMC, and LASIK. The preoperative and postoperative MRSE, preoperative corrected distance visual acuity, and postoperative uncorrected distance visual acuity (UDVA) were analyzed. RESULTS: Each group comprised 30 eyes. Follow-up was at least 6 months in the LASIK group and 12 months in the 2 PRK groups. There were no statistically significant differences in the mean preoperative MRSE (P=.95) or postoperative MRSE (P=.06) between the 3 groups. The mean postoperative MRSE was -0.07 diopter (D) ± 0.47 (SD), -0.14 ± 0.26 D, and 0.02 ± 0.25 D in the PRK with MMC 0.02% group, PRK without MMC group, and LASIK group, respectively. The variance in the postoperative MRSE in the PRK with MMC 0.02% group was significantly higher than that in the PRK without MMC group (P=.002) and in the LASIK group (P=.001). There was no statistically significant difference in the mean postoperative UDVA between the 3 groups (P=.47). CONCLUSIONS: Refractive outcomes after PRK for myopia were more variable when MMC 0.02% was used. This should be weighed against the advantage of intraoperative MMC use in reducing haze after PRK.

Comparison of posterior corneal imaging before and after LASIK using dual rotating scheimpflug and scanning slit-beam corneal tomography systems.

PURPOSE: To compare the maximum posterior elevation (MPE) measurements before and after LASIK using a dual rotating Scheimpflug (DRS) imaging system (Galilei, Ziemer Ophthalmic Systems, Port, Switzerland) and a scanning slit-beam (SSB) imaging system (Orbscan IIz, Bausch & Lomb, Rochester, NY). METHODS: This retrospective study included 78 eyes from 78 patients who underwent myopic LASIK. Preoperative and postoperative data collected included anterior and posterior best-fit sphere radius and axial curvature readings, posterior central elevation (PCE), and MPE relative to a best-fit sphere using a 7.8-mm region of interest. Data were compared using paired t test analysis. RESULTS: Mean preoperative PCE (5.06 ± 2.29 µm with the DRS system and 12.78 ± 6.90 µm with the SSB system) and MPE (4.87 ± 4 µm with the DRS system and 15.44 ± 9.78 µm with the SSB system) were statistically different (P < .001). Mean postoperative PCE (4.55 ± 2.34 µm with the DRS system and 20.59 ± 8.11 µm with the SSB system) and MPE (4.90 ± 3.35 µm with the DRS system and 24.95 ± 10.15 µm with the SSB system) were statistically different (P < .001). The difference between preoperative and postoperative MPE measurements by DRS was not statistically significant (P = .953), whereas the difference measured by SSB was statistically significant (P < .001). CONCLUSIONS: The consistency of DRS measurements suggests that the posterior surface of the cornea does not change appreciably after keratorefractive surgery and is imaged more accurately using DRS compared with SSB. The DRS system affords confidence in interpreting data that are useful for discerning morphologic abnormalities of the cornea, both before and after keratorefractive surgery.

Efficacy and tolerability of a combined moxifloxacin/dexamethasone formulation for topical prophylaxis in phacoemulsification: an open-label single-arm clinical trial.

Background. The use of a fixed-combination antibiotic corticosteroid for infection prophylaxis in Asian patients undergoing phacoemulsification has not been reported. Methods. A 15-day, open-label, single-arm trial of 64 patients for phacoemulsification with intraocular lens (IOL) implantation is described. Patients applied moxifloxacin 0.5%/dexamethasone 0.1% (Vigadexa) eye drops four times daily before and until 15 days after surgery. Anterior chamber (AC) reaction, visual acuity, ocular pain and signs, and intraocular pressure (IOP) were assessed at baseline and on postoperative days 1, 3, 8, and 15. Results. At day 15, 55 (91.7%) patients scored 0 (<5 cells) in AC reaction. No surgery-related infection occurred. Mean best-corrected visual acuity improved 0.5 logMAR from baseline to 0.0 logMAR (P < .0001). Mean IOP remained at 12-13 mm Hg over the 15-day treatment. Only 2 patients (3.1%) reported minimum ocular pain. Two (3.1%) patients were shifted to prednisolone acetate for severe inflammation. At the end of the study period, 8.3% were given fluorometholone for 1 week for AC reaction grade >0. No drug-related adverse event was reported. Conclusion. Following phacoemulsification and IOL implantation, the topical combination moxifloxacin 0.5%/dexamethasone 0.1% was effective in preventing infection and controlling inflammation and was well tolerated.