Comparison of refractive and visual acuity results after Contoura® Vision topography-guided LASIK planned with the Phorcides Analytic Engine to results after wavefront-optimized LASIK in eyes with oblique astigmatism.

PURPOSE: To compare visual acuity and refractive results between topography-guided laser in situ keratomileusis (LASIK) planned with the Phorcides Analytic Engine (PAE) to results after wavefront-optimized (WFO) LASIK in subjects with preoperative oblique astigmatism in their manifest refraction. METHODS: This was a retrospective chart review of clinical results from eyes treated with topography-guided LASIK planned with PAE compared to eyes treated with WFO LASIK using the same Wavelight® excimer laser system. All included subjects had preoperative oblique astigmatism. Residual refractive error and visual acuity (uncorrected and corrected) were the measures of interest, at the visit closest to 90 days postoperative. RESULTS: A matched data set from 100 WFO and 97 PAE eyes was extracted from clinical records. At the postoperative visit the PAE group showed lower residual refractive cylinder (p = 0.04), uncorrected distance visual acuity (UDVA) (-0.06 PAE vs. -0.02 WFO, p < 0.01) and distance corrected visual acuity (CDVA) (p < 0.01). The percentage of eyes with a mean refraction spherical equivalent (MRSE) magnitude within 0.25 D and 0.50 D of plano was statistically significantly higher in the PAE group (p = 0.04 and 0.01, respectively). A statistically significantly higher percentage of eyes in the PAE group had UDVA better than or equal to -0.10 logMAR (20/16 Snellen, 36% vs 22%, p = 0.04). More eyes gained CDVA after surgery in the PAE group (53% vs 32%, p < 0.01). There were five enhancements in the WFO group versus none in the PAE group, a statistically significant difference (p = 0.03). CONCLUSIONS: Visual acuity and refractive outcomes after LASIK using PAE in eyes with oblique astigmatism in their preoperative refraction were statistically significantly better than those obtained when WFO treatment was used. The number of refractive outliers and the number of retreatments were also significantly lower with PAE treatment.

Clinical and refractive outcomes after topography-guided refractive surgery planned using Phorcides surgery planning software.

PURPOSE: To evaluate prospectively the clinical outcomes of topography-guided laser in situ keratomileusis (LASIK) surgery performed with Contoura Vision using the Wavelight excimer laser and planned with the Phorcides Analytical Engine. SETTING: Four clinical practices in the U.S. DESIGN: Prospective single-arm interventional study. METHODS: 130 eyes of 65 patients with myopia or myopic astigmatism were enrolled in a prospective study of visual and refractive outcomes after treatment with Contoura Vision using the Wavelight EX500 excimer laser to achieve optimal distance vision. At 3 months postoperatively, uncorrected distance visual acuity (UDVA), manifest refraction, and corrected distance visual acuity (CDVA) were measured and compared with previously published studies. RESULTS: At 3 months postoperatively, 100%, 89%, and 28% of eyes achieved UDVA of 20/20, 20/15, and 20/12.5 or better, respectively. 92% of eyes had postoperative UDVA equal to or better than their preoperative CDVA. Postoperative CDVA was equal to, 1 line better, or 2 lines better than the preoperative CDVA in 53%, 40%, and 6% of eyes, respectively. Only 1 eye lost 1 line of CDVA, and no eyes lost more than 1 line of CDVA. A statistically significant decrease was noted in subjective visual complaints, including glare, halos, difficulty driving at night, reading difficulty, starbursts, fluctuation in vision, and light sensitivity. CONCLUSIONS: The Phorcides Analytical Engine can be used to optimize visual outcomes for the correction of myopia and myopic astigmatism.

Microsporidial keratoconjunctivitis in a healthy patient with a history of LASIK surgery.

PURPOSE: To describe a case of microsporidia corneal infection in a HIV-negative patient who did not wear contact lenses. METHOD: Case report and review of literature. RESULTS: This is the first case report of a human immunodeficiency virus-negative individual, a non-contact lens wearer, with microsporidia infection. CONCLUSION: Microsporidia keratoconjunctivitis may occur in healthy subjects with no antecedent contact lens wear.

Case report: the correction of a high magnitude of astigmatism with laser-assisted in situ keratomileusis.

BACKGROUND: Laser-assisted in situ keratomileusis (LASIK) has undergone several evolutions since it was first approved by the U.S. Food and Drug Administration. Currently, excimer lasers are approved by the U.S. Food and Drug Administration to treat refractive errors with a standard ablation profile, a wavefront-optimized ablation profile, or a wavefront-guided ablation profile. Wavefront-optimized ablation profiles provide a simple method to precompensate for the expected fourth-order spherical aberration and higher-order astigmatism in the average eye. CASE REPORT: We report a case of a 39-year-old white man, with a high magnitude of mixed astigmatism in the right and left eyes, who was seeking refractive surgical options because he was unable to tolerate contact lenses. The patient underwent bilateral wavefront-optimized LASIK to correct his high degree of astigmatism. Wavefront-guided ablation, as in this patient, can not always be performed because the parameters are not within the allowable treatment profile. Four months after the primary LASIK treatment, the patient underwent a bilateral wavefront-optimized LASIK enhancement for residual astigmatism. CONCLUSION: This case focuses on the utilization of a wavefront-optimized LASIK treatment profile to eliminate a high magnitude of astigmatic refractive error without inducing higher-order aberrations. Wavefront-guided treatments are not required in most cases but should be considered if the magnitude of preoperative root-mean-square higher-order aberrations is greater than 0.35 µm. Wavefront-optimized aspheric corneal ablations attempt to avoid reducing the prolate eccentricity of the average cornea, and optimized treatments have shown improved visual outcomes compared with conventional LASIK treatments. A thorough knowledge of refractive surgery is important for any treating eye care practitioner to provide patients with the full range of options to correct all types of refractive errors.