Laser-Assisted Subepithelial Keratectomy (LASEK) as a Treatment for Post-Radial Keratotomy Hyperopia Wendy V. Anandajeya, BS S. A. Erzurum, MD, FRCS

Financial Interest Authors acknowledge the financial support of the Polena Trust for Ocular Research at the St. Elizabeth Development Foundation, Youngstown, Ohio, and David Gemmel, PhD for manuscript assistance. Statements are the sole responsibility of the authors. Authors have no financial conflict of interest associated with products described in the report Authors acknowledge the financial support of the Polena Trust for Ocular Research at the St. Elizabeth Development Foundation, Youngstown, Ohio, and David Gemmel, PhD for manuscript assistance. Statements are the sole responsibility of the authors. Authors have no financial conflict of interest associated with products described in the report

Purpose Purpose: To demonstrate operative experience with laser-assisted subepithelial keratectomy (LASEK) treatment for post-radial keratotomy hyperopia and describe literature-reported treatments for this error. Purpose: To demonstrate operative experience with laser-assisted subepithelial keratectomy (LASEK) treatment for post-radial keratotomy hyperopia and describe literature-reported treatments for this error.

Background  A common long term complication of RK has included a hyperopic shift. 1 According to the Prospective Evaluation of Radial Keratotomy study (PERK), 25%-43% of patients developed hyperopia of 1.00 diopter (D) or more on follow-up of 0.5 to 10 years postoperatively. 2  Numerous treatment modalities have been suggested to correct for this post-RK hyperopia: pharmacological measures, special suturing techniques, hyperopic automated lamellar keratoplasty, photorefractive keratectomy (PRK), and laser in situ keratomileusis (LASIK).  As far as the authors are aware, no studies have assessed the safety, efficacy and predictability of LASEK as a treatment modality for post-RK hyperopia. We describe our operative experience of LASEK for post-radial keratotomy hyperopia.

Methodology Patients and Setting: Five patients with a total of seven eyes had LASEK to correct for post-RK hyperopia. All patients underwent LASEK in order to treat post-RK hyperopic shift. All LASEK procedures were performed at the same refractive office by the same surgeon. However, previous radial keratotomy procedures were completed by different surgeons. Patients and Setting: Five patients with a total of seven eyes had LASEK to correct for post-RK hyperopia. All patients underwent LASEK in order to treat post-RK hyperopic shift. All LASEK procedures were performed at the same refractive office by the same surgeon. However, previous radial keratotomy procedures were completed by different surgeons. Intervention: LASEK was completed by using an alcohol solution (20%) on the cornea for 40 seconds to create an epithelial flap. After the epithelial flap was reflected, a VISX Star S4™ laser (Visx Inc. , California) was used to create the ablation and reshape the cornea. The laser was programmed prior to each procedure for the ablative “cut” based on the patient’s pre-operative refractive error. Once the laser ablation was completed, the surgeon replaced the epithelial flap back on the eye and a contact bandage lens was used to cover the eye and facilitate healing. Intervention: LASEK was completed by using an alcohol solution (20%) on the cornea for 40 seconds to create an epithelial flap. After the epithelial flap was reflected, a VISX Star S4™ laser (Visx Inc. , California) was used to create the ablation and reshape the cornea. The laser was programmed prior to each procedure for the ablative “cut” based on the patient’s pre-operative refractive error. Once the laser ablation was completed, the surgeon replaced the epithelial flap back on the eye and a contact bandage lens was used to cover the eye and facilitate healing.

Methodology Measurements: Preoperatively, corneal curvatures were measured using keratometry and topography. Visual acuity with and without correction were evaluated using standard clinical assessments. Visual acuities were tested using standard BVAT measurements. Patients’ visual acuity was tested uncorrected and best corrected on each visit. Preoperatively, cycloplegic refractions were performed on all patients. Postoperatively, manifest refractions were performed. Results reported were the last achieved uncorrected and best-corrected visions. Refractions were recorded on each visit. Measurements: Preoperatively, corneal curvatures were measured using keratometry and topography. Visual acuity with and without correction were evaluated using standard clinical assessments. Visual acuities were tested using standard BVAT measurements. Patients’ visual acuity was tested uncorrected and best corrected on each visit. Preoperatively, cycloplegic refractions were performed on all patients. Postoperatively, manifest refractions were performed. Results reported were the last achieved uncorrected and best-corrected visions. Refractions were recorded on each visit. Analysis: For standardization and subsequent analysis, visual acuity was converted to LogMar, and refraction was converted to spherical equivalent. Descriptive statistics, including mean, standard deviation and SEM were tabulated for pre- and post-operative visual acuity in LogMar spherical equivalent and diopter astigmatism. Differences between pre- and post measurement were analyzed using the two-tailed student’s t test with statistical significance assumed at α < Because bilateral procedures were conducted in two patients, a sensitivity analysis was conducted in which only left and only right measurements were retained. When compared to all eye analysis, statistical decisions for non-independent eye yielded the same results. Analysis: For standardization and subsequent analysis, visual acuity was converted to LogMar, and refraction was converted to spherical equivalent. Descriptive statistics, including mean, standard deviation and SEM were tabulated for pre- and post-operative visual acuity in LogMar spherical equivalent and diopter astigmatism. Differences between pre- and post measurement were analyzed using the two-tailed student’s t test with statistical significance assumed at α < Because bilateral procedures were conducted in two patients, a sensitivity analysis was conducted in which only left and only right measurements were retained. When compared to all eye analysis, statistical decisions for non-independent eye yielded the same results.

Results On pre-operative measurement average cycloplegic spherical equivalent was (SEM = 0.53) On pre-operative measurement average cycloplegic spherical equivalent was (SEM = 0.53) On postoperative measurement average manifest spherical equivalent was (SEM = 0.28). On postoperative measurement average manifest spherical equivalent was (SEM = 0.28). Mean change in spherical equivalent was (SEM = 0.67), which was clinically significant (2 tailed paired Student’s t test = 2.435, p = 0.051). Mean change in spherical equivalent was (SEM = 0.67), which was clinically significant (2 tailed paired Student’s t test = 2.435, p = 0.051). Preoperative diopter of astigmatism was (SEM = 0.26) Preoperative diopter of astigmatism was (SEM = 0.26) Postoperatively, astigmatism was (SEM = 0.11). Postoperatively, astigmatism was (SEM = 0.11). Mean improvement in diopter of astigmatism was (SEM = 0.23), demonstrating statistically significant improvement (2 tailed paired Student’s t test = 3.718, p = 0.01). Mean improvement in diopter of astigmatism was (SEM = 0.23), demonstrating statistically significant improvement (2 tailed paired Student’s t test = 3.718, p = 0.01).

Results On pre-operative measurement, average uncorrected LogMar was (SEM = 0.04). On pre-operative measurement, average uncorrected LogMar was (SEM = 0.04). On postoperative measurement, average uncorrected LogMar measurement, obtained 17.7 months after the procedure (range 4-35 months), improved to (SEM = 0.04). On postoperative measurement, average uncorrected LogMar measurement, obtained 17.7 months after the procedure (range 4-35 months), improved to (SEM = 0.04). Mean change in Log Mar uncorrected visual acuity, (SEM = 0.05), significantly improved (2 tailed paired Student’s t test = 5.793, p = 0.001). ). When this mean change was analyzed to account for non-independent eyes the improvement remained statistically significant (p = 0.01). Mean change in Log Mar uncorrected visual acuity, (SEM = 0.05), significantly improved (2 tailed paired Student’s t test = 5.793, p = 0.001). ). When this mean change was analyzed to account for non-independent eyes the improvement remained statistically significant (p = 0.01). Except in two eyes, all Log Mar best corrected acuities were 0. Both of these patients showed improvement in final, best corrected visual acuity, with one patient exhibiting improvement from 0.1 to 0 LogMar and the other patient exhibiting improvement from 0 to –0.12 LogMar. Except in two eyes, all Log Mar best corrected acuities were 0. Both of these patients showed improvement in final, best corrected visual acuity, with one patient exhibiting improvement from 0.1 to 0 LogMar and the other patient exhibiting improvement from 0 to –0.12 LogMar.

Conclusions In the current series, LASEK improved all of our patients’ uncorrected visual acuity and they all maintained best corrected visual acuity. In the current series, LASEK improved all of our patients’ uncorrected visual acuity and they all maintained best corrected visual acuity. All patients were spectacle free after their LASEK procedure and had a high satisfaction level. All patients were spectacle free after their LASEK procedure and had a high satisfaction level. Hyperopia and refractive error were reduced in all patients as demonstrated by improvements in measured diopter. Hyperopia and refractive error were reduced in all patients as demonstrated by improvements in measured diopter. In all eyes, marked improvement in UCVA was notable in the series -- eyes in this study reached uncorrected VA of 20/30 of better. In all eyes, marked improvement in UCVA was notable in the series -- eyes in this study reached uncorrected VA of 20/30 of better. Likewise, LogMar improvement was statistically significant. All eyes of this study received a postoperative BCVA acuity of 20/20 or better. Likewise, LogMar improvement was statistically significant. All eyes of this study received a postoperative BCVA acuity of 20/20 or better. All patients were evaluated 1-3 months postoperatively via slip lamp exam and exhibited clear cornea with no sign of haze or recurrent erosions. All patients were evaluated 1-3 months postoperatively via slip lamp exam and exhibited clear cornea with no sign of haze or recurrent erosions. Most patients have also been evaluated on long-term followup, at 2 years, with sustained visual improvement and no long-term sequelae. Most patients have also been evaluated on long-term followup, at 2 years, with sustained visual improvement and no long-term sequelae.

Biography Wendy Anandajeya is currently a fourth year medical student at Northeastern Ohio Universities College of Medicine (NEOUCOM). She will continue her ophthalmology training in Washington D.C. at Georgetown University/Washington National Hospital starting in Wendy Anandajeya is currently a fourth year medical student at Northeastern Ohio Universities College of Medicine (NEOUCOM). She will continue her ophthalmology training in Washington D.C. at Georgetown University/Washington National Hospital starting in Dr. Sergul Erzurum is Chief of Ophthalmology in the Department of Surgery at Forum Health in Youngstown, Ohio and Professor of Surgery at NEOUCOM. She is in private practice at Eye Care Associates in Youngstown, Ohio Dr. Sergul Erzurum is Chief of Ophthalmology in the Department of Surgery at Forum Health in Youngstown, Ohio and Professor of Surgery at NEOUCOM. She is in private practice at Eye Care Associates in Youngstown, Ohio

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