Refractive changes during orthokeratology treatment are mainly induced by changes in epithelial thickness profile, while stromal changes may also contribute to a small extent.

Purpose: To evaluate the monocular and binocular outcomes of LASIK for a micro-monovision protocol for the correction of hyperopic astigmatism and presbyopia. Methods: A prospective non-comparative case series included 258 eyes of 129 consecutive patients with hyperopic astigmatism and presbyopia who were treated with LASIK-induced micro-monovision. The CRS-Master software was used to generate ablation profiles for the Carl Zeiss Meditec MEL80 excimer laser. The target refraction was plano for distance eyes (dominant eye) and between −1.00 and −1.50 diopters (D) for near eyes. Patients were followed for 1 year. Results: Mean attempted spherical equivalent refraction (SE) correction was +2.54±1.16 D (range: +0.25 to +5.75 D). Mean attempted cylinder was −0.52±0.49 D (range: −0.00 to −3.25 D). Median age was 56 years (range: 44 to 66 years). Median follow-up was 12.5 months (range: 3.3 months [early retreatment] to 18.2 months). The retreatment rate was 22%. Outcome measures after all treatments were as follows. Mean deviation from the intended SE correction was +0.09±0.48 D, with 79% of eyes within ±0.50 D and 95% within ±1.00 D. The cylinder correction ratio was 1.23±0.63 and the error ratio was 0.67±0.65. Of the distance eyes, 86% achieved uncorrected visual acuity of 20/20 and 100% achieved 20/40. Binocularly, 95% of patients achieved 20/20 and 100% achieved 20/40. Eighty-one percent of patients could read J2 and 100% could read J5. Binocularly, 95% of patients achieved 20/20 and could read J5. No eyes lost 2 or more lines of best spectacle-corrected visual acuity. A statistically significant increase was noted in contrast sensitivity at 3 and 6 cycles per degree (cpd), with no reduction at 12 and 18 cpd. The average change in refraction between 3 months and 1 year was +0.11±0.36 D with a change of >1.00 D in 2.6% of eyes. Conclusions: This hyperopic micro-monovision protocol was a well-tolerated and effective procedure for treating patients with presbyopia in moderate to high hyperopia with corrections ranging up to +5.75 D. Contrast sensitivity was improved and the distance vision of near eyes was found to contribute positively to binocular distance vision compared to distance eyes monocularly. [ J Refract Surg . 2009;25:37–58.]

Epithelial thickness maps provide useful information for monitoring the progression of corneal ectasia after corneal collagen CXL, showing in this case, at least no further progression of the ectasia.

PURPOSE: To evaluate the accuracy of myopic refraction by a single measurement using the Wavefront Supported Custom Ablation (WASCA) aberrometer (Carl Zeiss Meditec AG, Jena, Germany). METHODS: We retrospectively compared the refractive errors obtained by manifest refraction and wavefront refraction (WASCA) in 50 eyes of 25 consecutive myopic patients undergoing laser refractive surgery. The sphere ranged from -1.00 to -8.25 diopters (D) and cylinder from 0 to -3.75 D. WASCA measurements under cycloplegia were made and WASCA refractions calculated for a 6-mm analysis zone using the Seidel method within the WASCA. We used the manifest refraction as our best estimate of the true refractive error, therefore accuracy was defined as the difference between manifest refraction and that of the WASCA. Correlation coefficients and mean vector errors between manifest and WASCA refraction were calculated. RESULTS: High correlation was shown between manifest and WASCA refractions, with correlation coefficients (R2) of 0.97, 0.85, and 0.79 for M, J180, and J45, respectively. Mean power vector error (standard deviation) was 0.22 D (0.39), +0.03 D (0.21), and +0.03 D (0.13) for M, J180, and J45, respectively. Total dioptric power vector error was 0.43 D with 74% eyes within 0.50 D. CONCLUSIONS: When measuring normal myopic eyes, the concordance between manifest and WASCA refractions was found on average to be high; however, outlier measurements occurred. [J Refract Surg. 2006;22:268-274.]

We present a patient scheduled for LASIK enhancement based on conventional residual stromal thickness (RST) prediction methods in whom direct measurement of the RST changed the management due to an unexpectedly low RST. The preoperative refraction was -6.00 -0.50 x 115 in the right eye and -6.00 -0.50 x 20 in the left eye. At 9 months, the refractions had regressed to -0.50 -0.50 x 150 and -0.75 -0.25 x 145, respectively. Predicted RST based on preoperative parameters was 283 microm in the right eye and 281 microm in the left eye, sufficient for the planned enhancement. Using the Artemis 3-dimensional very high-frequency digital ultrasound arc scanner, the minimum RST was directly measured as 277 microm in the right eye but only 212 microm in the left eye, which may have significantly increased the risk of iatrogenic ectasia yielding a predicted post-enhancement RST of 253 microm and 192 microm, respectively. The treatment plan was altered as a result of the thinner than predicted RST in the left eye; an enhancement was performed in the right eye only. A second Artemis examination after 22 months found the RST in the left eye to be stable.