PURPOSE: We compared the results of photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK) for the correction of hyperopia. METHODS: Patients who underwent PRK or LASIK, under +6.00 diopters (D) hyperopia and under −2.00 D astigmatism were included. In total, 21 patients (38 eyes) underwent PRK surgery and 25 patients (41 eyes) underwent LASIK surgery. We compared the visual acuity, refractive error, safety, and efficacy between the two groups. RESULTS: The manifest refractive spherical equivalent (MRSE) of the PRK and LASIK groups at 1 and 3 months after surgery was significantly different between the two groups (p < 0.05). However, the MRSE was not significantly different at postoperative 6 and 12 months between the two groups. The uncorrected visual acuity (UCVA) of the PRK and LASIK groups at 1 month after surgery was significantly different between the two groups (p < 0.05). However, the UCVA was not significantly different at postoperative 3, 6, and 12 months between the two groups. The best-corrected visual acuity was not significantly different at postoperative 1, 3, 6, and 12 months between the two groups. The safety index was not significantly different between the two groups at postoperative 1, 3, 6, and 12 months. The efficacy index of the PRK group was lower than that of the LASIK group at 1 month after surgery. However, the efficacy index was not significantly different at postoperative 3, 6, and 12 months between the two groups. There was no statistically significant difference between the predictability of the two groups at postoperative 1 year. CONCLUSIONS: After PRK treatment, temporary myopic deviation was observed after 1 month, but there was no significant difference between the two treatments after 3 months of follow-up. In the correction of hyperopia, there was no significant difference between PRK and LASIK in efficacy or safety.
Astigmatism ; Follow-Up Studies ; Humans ; Hyperopia ; Keratomileusis, Laser In Situ ; Photorefractive Keratectomy ; Refractive Errors ; Visual Acuity

PURPOSE: To investigate the clinical effects of different orientation and magnitude of cyclotorsion on the compensation capacity of the WaveLight EX500 photorefractive keratectomy (PRK) platform. METHODS: This retrospective study comprised 400 eyes of 200 patients who underwent bilateral simultaneous PRK due to compound myopic astigmatism. The subjects were separated according to the orientation of cyclotorsion into incyclotorsion and excyclotorsion groups, and by the magnitude of cyclotorsion into group 1 (0.50 to 2.50 degrees), group 2 (3.00 to 5.00 degrees), group 3 (5.50 to 7.50 degrees), and group 4 (8.00 to 9.50 degrees). RESULTS: The mean magnitude of cyclotorsion was 3.50 ± 2.4 degrees (0.50 to 9.50 degrees) in the incyclotorsion group and 3.32 ± 2.3 degrees (0.50 to 9.50 degrees) in the excyclotorsion group (p = 0.617). The postoperative refractive outcomes of the incyclotorsion and excyclotorsion groups were similar (p > 0.05 for all). The postoperative mean cylindrical refractive error was −0.32 ± 0.3 diopters (D, −1.25 to 0.00 D) in group 1, −0.47 ± 0.2 D (−2.00 to 0.00 D) in group 2, −0.62 ± 0.2 D (−1.00 to −0.25 D) in group 3, and −0.91 ± 0.2 D (−1.50 to −0.50 D) in group 4 (p < 0.001). Preoperative cylindrical refractive error was positively correlated with magnitude of cyclotorsion (r = 0.125 and p = 0.013), which was also positively correlated with postoperative cylindrical refractive error (r = 0.600 and p < 0.001). CONCLUSIONS: Incyclotorsion and excyclotorsion can be equally compensable in the WaveLight EX500 PRK platform for compound myopic astigmatism. A value of ≤2.50 degrees cyclotorsion magnitude was observed to be more compensable than higher degrees of cyclotorsion magnitude. Preoperative high astigmatism was associated with high cyclotorsion magnitude, which was also associated with a high degree of postoperative astigmatism.
Astigmatism ; Compensation and Redress ; Humans ; Myopia ; Photorefractive Keratectomy ; Refractive Errors ; Refractive Surgical Procedures ; Retrospective Studies

PURPOSE: To assess the validity of central corneal thickness (CCT) and corrected intraocular pressure (IOP) values obtained by tono-pachymetry in non-surgical and post-photorefractive keratectomy (PRK) eyes. METHODS: For the study, 108 young healthy participants and 108 patients who had PRK were enrolled. Measurements were randomly performed by tono-pachymetry, ultrasonic (US) pachymetry, and Goldmann applanation tonometry (GAT). CCT measurement by tono-pachymetry was compared to that of US pachymetry. The corrected IOP value obtained by tono-pachymetry was compared to that obtained by US pachymetry and GAT. The corrected IOP from US pachymetry and GAT was calculated using the identical compensation formula built into the tono-pachymetry. Bland-Altman plot and paired t-test were conducted to evaluate the between-method agreements. RESULTS: The mean CCT measurement using tono-pachymetry was significantly greater by 7.3 µm in non-surgical eyes (p < 0.001) and 17.8 µm in post-PRK eyes (p < 0.001) compared with US pachymetry. Differences were significant in both Bland-Altman plotand paired t-test. The mean difference of corrected IOP values obtained by tono-pachymetry and calculated from measurements by US pachymetry and GAT was 0.33 ± 0.87 mmHg in non-surgical eyes and 0.57 ± 1.08 mmHg in post-PRK eyes. The differences in the Bland-Altman plot were not significant. CONCLUSIONS: The CCT measurement determined using tono-pachymetrywas significantly thicker than that of US pachymetry. The difference in CCT was greater in post-PRK eyes than in non-surgical eyes. However, the corrected IOP value obtained by tono-pachymetry showed reasonable agreement with that calculated from US pachymetry and GAT measurements.
Compensation and Redress ; Corneal Pachymetry ; Healthy Volunteers ; Humans ; Intraocular Pressure* ; Manometry ; Photorefractive Keratectomy ; Ultrasonics

PURPOSE: The purpose of this study was to investigate the clinical efficacy of an optimized prolate ablation procedure for correcting residual refractive errors following laser surgery. METHODS: We analyzed 24 eyes of 15 patients who underwent an optimized prolate ablation procedure for the correction of residual refractive errors following laser in situ keratomileusis, laser-assisted subepithelial keratectomy, or photorefractive keratectomy surgeries. Preoperative ophthalmic examinations were performed, and uncorrected distance visual acuity, corrected distance visual acuity, manifest refraction values (sphere, cylinder, and spherical equivalent), point spread function, modulation transfer function, corneal asphericity (Q value), ocular aberrations, and corneal haze measurements were obtained postoperatively at 1, 3, and 6 months. RESULTS: Uncorrected distance visual acuity improved and refractive errors decreased significantly at 1, 3, and 6 months postoperatively. Total coma aberration increased at 3 and 6 months postoperatively, while changes in all other aberrations were not statistically significant. Similarly, no significant changes in point spread function were detected, but modulation transfer function increased significantly at the postoperative time points measured. CONCLUSIONS: The optimized prolate ablation procedure was effective in terms of improving visual acuity and objective visual performance for the correction of persistent refractive errors following laser surgery.
Coma ; Humans ; Keratectomy, Subepithelial, Laser-Assisted ; Keratomileusis, Laser In Situ ; Laser Therapy* ; Phosmet* ; Photorefractive Keratectomy ; Refractive Errors* ; Refractive Surgical Procedures ; Treatment Outcome ; Visual Acuity

PURPOSE: To determine the effectiveness of the method for preventing corneal opacity and minimizing the intraocular pressure (IOP) increase after photorefractive keratectomy treated with 0.1% fluorometholone and tranilast (0.5% tranilast, Krix®, JW pharmaceutical, Seoul, Korea), especially in cases with elevated IOP. METHODS: The patients who underwent photorefractive keratectomy from May 2014 to May 2015 were enrolled in the present study. The data of 49 patients (49 eyes) with elevated IOP at 1 month postoperatively and who used 0.1% fluorometholone and tranilast eye drops (tranilast group) were analyzed and compared with the control group consisting of patients who underwent the same surgery from December 2012 to October 2013 but used only 0.1% fluorometholone. RESULTS: The visual acuity at postoperative 6 months was log MAR -0.08 ± 0.05 and log MAR -0.08 ± 0.04 in the tranilast group and control group, respectively. The eye drops were used postoperatively for 17.7 ± 3.3 weeks in the tranilast group and for 20.5 ± 3.7 weeks in the control group (p < 0.01). Anti-glaucoma eye drops were used for 18.4 ± 3.2 weeks and 20.9 ± 3.7 weeks postoperatively in the tranilast group and control group, respectively (p < 0.01). CONCLUSIONS: Adding tranilast eye drops to patients whose IOP was elevated because of 0.1% fluorometholone use after photorefractive keratectomy is an effective method for preventing corneal haze and minimizing IOP elevation.
Corneal Opacity ; Fluorometholone* ; Humans ; Intraocular Pressure ; Ophthalmic Solutions* ; Photorefractive Keratectomy* ; Seoul ; Visual Acuity

PURPOSE: To evaluate the effect of 0.05% cyclosporine A on the ocular surface after photorefractive keratectomy (PRK). METHODS: This retrospective study included 50 patients who underwent PRK. Patients were divided into two groups: 25 patients in group I were treated with topical 0.05% cyclosporine A with conventional medication, and 25 patients in group II were treated with conventional medication. Visual acuity (VA), tear break-up time (BUT), fluorescein staining score (F-stain), Schirmer I test, and ocular surface disease index (OSDI) were evaluated before surgery and 2 weeks, 1 month, 2 months, and 3 months after surgery. RESULTS: F-stain was significantly lower in group I than in group II at 2 weeks and 1 month (p < 0.05). There was no significant difference in uncorrected VA, BUT, Schirmer I test, or OSDI between the groups. However, group I showed a more effective pattern in dry eye. CONCLUSIONS: Combination treatment with 0.05% cyclosporine A was helpful for early ocular surface stability in patients with dry eye after PRK.
Cyclosporine* ; Fluorescein ; Humans ; Photorefractive Keratectomy* ; Refractive Surgical Procedures ; Retrospective Studies ; Tears ; Visual Acuity

PURPOSE: Nystagmus is not considered a good indication for laser refractive surgery. However, we report 2 cases with congenital nystagmus that underwent a safe procedure due to improvement of laser firing rate and eye tracker. CASE SUMMARY: Two myopic patients with congenital nystagmus underwent transepithelial photorefractive keratectomy with the Schwind Amaris laser platform using an eye tracker. The laser ablations were performed under topical anesthesia without any mechanical eyeball fixation. A 30-year-old man with a history of muscle surgery at 11 years of age had a conjugate, 4 Hz right beating jerk nystagmus. His preoperative refractive error was -8.50 D sph = -0.50 D cyl x 160degrees x 20/30) in the right eye, and -6.00 D sph = -0.75 D cyl x 30degrees x 20/25) in the left eye. A 19-year-old man had a conjugate, 3 Hz pendular nystagmus. His refractive error was -5.25 D sph = -2.50 cyl x 175degrees x 20/30) in the right eye, and -4.25 D sph = -2.50 D cyl x 180degrees x 20/30) in the left eye. Both patients underwent a well-centered laser ablation without any problems. Six months after surgery, uncorrected visual acuity was 20/25 or better, and refractive error was within +/-0.50 D in all 4 eyes. In addition, the 19-year-old man showed decreased nystagmus amplitude. CONCLUSIONS: In some patients with congenital nystagmus, laser refractive surgery may be safely and accurately performed under topical anesthesia using an active tracking system. The best uncorrected visual acuity may improve in certain patients postoperatively.
Adult ; Anesthesia ; Fires ; Humans ; Laser Therapy ; Nystagmus, Congenital* ; Nystagmus, Pathologic ; Photorefractive Keratectomy ; Refractive Errors ; Refractive Surgical Procedures* ; Visual Acuity ; Young Adult

No abstract available.
Adult ; Corneal Opacity/etiology/pathology/*surgery ; Female ; Humans ; Male ; Monitoring, Intraoperative/*methods ; Photorefractive Keratectomy/*adverse effects ; Postoperative Complications/etiology/pathology/*surgery ; Young Adult

PURPOSE: We investigated the incidence of retinal lesions before and after surgery and the percentage of preoperative prophylactic laser treatment in patients who underwent corneal refractive surgery or phakic intraocular lens implantation (pIOLi). METHODS: The medical records of patients who underwent refractive surgery from January 2005 to June 2013 were reviewed retrospectively. We investigated the incidence and type of retinal lesions identified during the preoperative examination. Additionally, the percentage of preoperative prophylactic laser treatment and the incidence of postoperative newly developed retinal lesions were analyzed. RESULTS: A total of 894 eyes of 466 subjects (laser in situ keratomileusis [LASIK] 225 eyes, 117 subjects; laser-assisted subepithelial keratectomy [LASEK] or photorefractive keratectomy [PRK] 450 eyes, 231 subjects; pIOLi 219 eyes, 121 subjects) were enrolled in the present study. Retinal lesions were found in 268 eyes (29.98%) and of those, 144 eyes (16.11%) received prophylactic laser treatment. Postoperative newly developed retinal lesions were detected in 8 cases (LASEK or PRK, 5 cases; pIOLi, 3 cases) during the follow-up period. There was a significant correlation between preoperative spherical equivalent and the presence of retinal lesions. CONCLUSIONS: The patient population of refractive surgery is largely myopic and thus particularly vulnerable to retinal lesions. Additionally, a considerable number of patients required preoperative prophylactic laser treatment. Therefore, both surgeons and patients should be aware of the risks of developing postoperative retinal lesions.
Follow-Up Studies ; Humans ; Incidence* ; Keratectomy, Subepithelial, Laser-Assisted ; Medical Records ; Myopia ; Phakic Intraocular Lenses ; Photorefractive Keratectomy ; Refractive Surgical Procedures* ; Retinaldehyde* ; Retrospective Studies

PURPOSE: To evaluate the efficacy of combined photorefractive keratectomy (PRK) and cataract surgery in granular corneal dystrophy (GCD) patients with corneal stromal haziness compromising vision and cataract and clinically significant lens opacity. METHODS: Medical records of 12 eyes that underwent PRK and cataract surgery between August 2009 and November 2013 in patients with GCD and cataracts were retrospectively evaluated. All PRKs were performed with the VISX S4 IR (VISX, Santa Clara, CA, USA). The double K SRK-T formula or double K Hoffer Q formula and postoperative corrected K were utilized to determine the intraocular lens power in patients with prior PRK. Postoperative best corrected visual acuity (BCVA), spherical equivalent, presence of the central island using topography analysis and recurrence of corneal opacity after combined PRK and cataract surgery were evaluated. RESULTS: In all eyes, the PRK was successful and 3 eyes showed recurrence of corneal opacities without visual impairment during a mean follow-up of 36.6 months. The mean BCVA improved with an average increase of 4.63 lines (minimum 1 line, maximum 9 lines) and no patient showed any BCVA loss. Final spherical equivalent was -0.56 diopter (D) and the corneal central island was reported in only 1 eye. The Maloney method using the double-K formula with the SRK/T formula showed the lowest absolute error of 0.33 +/- 0.25 D. CONCLUSIONS: Combined PRK and cataract surgery are effective methods for improving BCVA if patients with GCD have both visually significant diffuse corneal haze and clinically significant lens opacity.
Cataract* ; Corneal Opacity ; Follow-Up Studies ; Humans ; Lenses, Intraocular ; Medical Records ; Photorefractive Keratectomy* ; Recurrence ; Retrospective Studies ; Vision Disorders ; Visual Acuity