Simultaneous Photorefractive Keratectomy Research Articles

Merging Photorefractive Keratectomy and Collagen Crosslinking: An Analysis of Literature and a Guide to Prevalent Protocols.

The purpose of this review was to summarize the different surgical approaches combining photorefractive keratectomy (PRK) and corneal crosslinking (CXL), present each protocol template in a simple format, and provide an overview of the primary outcomes and adverse events. A literature review was conducted as outlined by the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. Eight different databases were searched. Papers were included if PRK was immediately followed by CXL. Thirty-seven papers met the inclusion criteria of a total yield of 823. The latest research into simultaneous PRK and CXL has been shown to not only stabilize the cornea and prevent keratoconus progression but also improve the visual acuity of the patient. Improvements in uncorrected distance visual acuity and (spectacle) corrected distance visual acuity were found to be significant when considering all protocols. There were also significant reductions in K1, K2, mean K, Kmax, sphere, cylinder, and spherical equivalent. Random-effects analysis confirmed these trends. Corrected distance visual acuity was found to improve by an average of 0.18 ± 1.49 logMAR (Cohen's D [CD] 0.12; P <0.02). There was also a significant reduction of 2.57 ± 0.45 D (CD 5.74; P <0.001) in Kmax. Cylinder and spherical equivalent were also reduced by 1.36 ± 0.26 D (CD 5.25; P <0.001) and 2.61 ± 0.38 D (CD 6.73; P <0.001), respectively. Combining the 2 procedures appears to be of net benefit, showing stabilization and improvement of ectatic disease, while also providing modest gains in visual acuity. Since customized PRK and CXL approaches appear superior, a combination of these would likely be best for patients.

Combined simultaneous photorefractive keratectomy and collagen cross-linking in keratoconus suspect patients

To evaluate the safety and efficacy of combined simultaneous photorefractive keratectomy (PRK) with collagen cross-linking (CXL) in keratoconus suspects (KCS). This was a retrospective, non-randomized study of KCS patients who underwent combined simultaneous PRK with CXL. The efficacy, safety, refractive outcomes, and corneal wavefront aberration changes were assessed after the surgery and compared with existing preoperative data. Fifty-six eyes of 28 patients, including 20 females (71.4%), with a mean age of 30.92±4.09 years, were enrolled. The mean follow-up was 19.46±8.48 months (range: 7-35). At the conclusion of the study, mean uncorrected distance visual acuity LogMAR improved from 0.89±0.44 preoperatively to 0.04±0.09 postoperatively (P<0.001). In addition, a statistically significant corneal flattening was observed postoperatively, with a decrease in manifest refraction. A statistically significant increase was found in higher-order aberrations (P<0.001), horizontal coma (P<0.001), and spherical aberration (P<0.001) compared with preoperatively. Postoperatively, 41% exhibited refractive astigmatism of 0.50 diopter (D) or less; 83.8% showed 1.00 D or less. The results of our study indicate that combined simultaneous PRK with CXL can be a safe and effective method for treating refractive instability in KCS patients.

Corneal Cross-Linking for Keratoconus and Post-LASIK Ectasia and Failure Rate: A 3 Years Follow-Up Study.

PurposeTo report the response of keratoconus (KC) and post-LASIK ectasia (referred to as “ectasia”) to the corneal crosslinking (CXL) and to compare the rate of progression between KC and ectasia at three years.MethodsA retrospective cohort study of patients undergoing CXL for either KC or ectasia. Fifty-four eyes (31 patients) with ectasia and 111 eyes (67 patients) with KC were included in the study. Corrected distance visual acuities (CDVA), refraction, keratometry (K), and pachymetry were followed up for three years. Simultaneous photorefractive keratectomy (PRK) and CXL were performed on 20 KC and 20 ectasia eyes. Intrastromal Corneal Ring Segments (ICRS) were performed on 51 KC and six ectasia eyes.ResultsIn KC, CDVA, spherical equivalence, sphere, cylinder, and mean K improved at three years post-CXL (p-value<0.05), but these values improved without reaching a statistical significance in ectasia(p-values <0.05). 12 of 54 eyes with ectasia (22.2%) and 4 of 111 eyes (3.6%) with KC had progression post CXL(p-value:0.0001). Ectasia patients diagnosed with progression were older at presentation (36.1 years) than non-progressive ectasia patients (31 years) (p-value 0.02) and also older than KC patients.Sub-analysis excluding PRK and ICRS cases showed that there was an improvement in mean sphere (from -5.23±4.2D to-4.46±3.89D) (p-value 0.03) cylinder (from 2.54 ± 1.68D to 1.97 ± 1.51D) (p-value 0.03) mean keratometry (from 46.81 ± 3.78D to 46.01 ± 3.25D) (p-value 0.006) in KC patients 3 years post CXL (40 patients). Compared to baseline, all the mean refractive and topographic variables deteriorated at three years post CXL in ectasia (28 patients) (p-value>0.05). Also, 2 of 40 patients with KC (5%) vs. 7 of 28 patients with ectasia (25%) had progression three years post-CXL, and the difference between both groups remained statistically significant(p-value 0.027).ConclusionEyes with post-LASIK ectasia seem to be less responsive to CXL than KC.

Long-Term Follow-Up of Combined Photorefractive Keratectomy and Corneal Crosslinking in Keratoconus Suspects.

PurposeTo present the long-term outcomes of photorefractive keratectomy (PRK) combined with accelerated corneal cross-linking (CXL) for refractive error correction in a series of keratoconus suspects.SettingUniversity practice.DesignRetrospective case series.MethodsA series of patients with topographic findings suspicious for keratoconus underwent simultaneous PRK and prophylactic accelerated CXL (5 minutes with intensity of 18 mW/cm2) for the correction of their refractive error. The results were recorded for more than 4 years postoperatively.ResultsTen eyes of 5 patients were included. Mean follow-up was 58.2 months (range from 54 to 62 months). Mean age at presentation was 25 years (range from 22 to 32 years). Mean spherical equivalent (SE) refraction was −2.76 (standard deviation [SD] 0.97D, range from −1.25 to −4.00 diopters [D]), while mean central corneal thickness was 511μm (SD 13μm, range from 485 to 536 μm). At last, follow-up 9 out of 10 eyes had SE refraction within ± 0.50D and all eyes had SE within ± 1.00D. None of the eyes lost any line of corrected distance visual acuity (CDVA), whereas 1 eye gained one line of CDVA. All eyes demonstrated stability of their results during the follow-up period.ConclusionSimultaneous PRK followed by prophylactic accelerated CXL (PRK plus) appeared to be a safe and effective option for the correction of the refractive error in this series of keratoconus suspect patients, without compromising corneal stability for up to 5 years postoperatively.

Simultaneous photorefractive keratectomy and accelerated collagen cross-linking in high-risk refractive surgery(Tehran protocol): 3-year outcomes.

To evaluate safety and efficacy of performing simultaneous photorefractive keratectomy (PRK) and collagen cross-linking (CXL) in myopic patients with preoperative risk factors for developing keratectasia. Seventeen eyes of 15 patients with at least one of the following risk factors were recruited: central keratometry (Kmax) between 48 and 50, difference between inferior, superior corneal power (I-S value) between 1.4 and 1.9 and corneal thickness between 450 and 480µm. Upon final stage of standard PRK, 0.02% mitomycin was applied for 30-50s, and then, accelerated CXL was performed for 5min. Pre- and postoperative Oculus Pentacam® imaging for keratometry values, measurement of uncorrected distance visual acuity (UDVA) and corrected distance visual acuity (CDVA) were done for all patients. Mean follow-up time was 32.08 ± 7.79months (range 25-49months). Mean age of patients was 28.78 ± 3.80years. Mean postoperative spherical equivalent was + 0.19 ± 0.42 (- 0.5 to + 1.0 [D]). Mean UDVA and CDVA improved from 0.9062 ± 0.485 log MAR and 0.0148 ± 0.043 log MAR to 0.0173 ± 0.040 log MAR and 0.0057 ± 0.023 log MAR, respectively (P = 0.011, P = 0.735). Mild degree of early postoperative stromal haze was seen which did not persist more than 6months. There was no late stromal haze, corneal ectasia or other major postoperative complication in the follow-up period. Combined PRK and accelerated CXL is an efficient and safe procedure for high-risk refractive surgery candidates, with no increased risk of persistent corneal haze.

Outcomes of simultaneous photorefractive keratectomy and collagen crosslinking

ObjectiveTo report the outcomes and complications of combined photorefractive keratectomy (PRK) and collagen crosslinking (CXL). DesignA retrospective cohort study of consecutive patients undergoing combined PRK-CXL between 2011 and 2013 at Care Laser, Inc, Tel Aviv, Israel. ParticipantsNinety-eight eyes of 56 patients were included. Only patients without keratoconus were included. MethodsData were collected from the patients’ files and imaging devices. Main outcome measures were corrected and uncorrected distance visual acuity (CDVA/UDVA); spherical equivalent (SE); refractive, keratometric, and pachymetric stability; and the occurrence of postoperative complications. ResultsMean age was 27.69 ± 6.6 years. UDVA improved from 1.38 ± 0.60 to 0.15 ± 0.24 logMAR (p < 0.001). SE improved from −4.45 ± 2.87 diopter (D) to +0.20 ± 0.90 D (p < 0.001), and 69% of the patients were within ±0.50 D from emmetropia. Four eyes had significant corneal haze; of them 3 eyes lost more than 2 Snellen lines. No cases of corneal ectasia were recorded. ConclusionsIn our cohort PRK-CXL achieved significantly improved UDVA and SE compared to baseline. Corneal haze was a significant complication. Refractive results were less accurate than published for patients undergoing PRK procedures. Although no cases of corneal ectasia were seen, given the rarity of such complication, the added benefit of CXL remains to be proven.

Short-term visual result after simultaneous photorefractive keratectomy and small-aperture cornea inlay implantation.

PurposeTo report the short-term results of simultaneous photorefractive keratectomy (PRK) and small-aperture cornea inlay implantation (KAMRA) surgery in treating presbyopia.MethodsSimultaneous PRK and KAMRA inlay surgery was performed on 21 patients from July 2015 to March 2016. Follow-up exams were conducted at 1, 3, and 6 months postoperatively. Our patients were also divided preoperatively into three categories: myopic, hyperopic, and emmetropic. Over the 6-month period, the main outcome measures were uncorrected near visual acuity (UNVA), changes in best-corrected distance visual acuity, and mean spherical equivalent refraction.ResultsAt 6-month follow-up, 83% (10/12) of patients had a monocular UNVA of 20/40 or better, and 75% had a binocular UNVA of 20/40 (J5) or better. At 6 months, the overall mean refractive spherical equivalent (MRSE) was −0.60 D (±0.42 standard deviation [SD], range: −1.38 to −0.13) with a mean change of −0.43 D (±1.19 SD, range: −1.5 to 2.63) compared to preoperative data. Overall, 91% (10/11) of patients were within a ±0.5 D range of our target −0.75 D for KAMRA use. One-hundred percent (5/5) of the hyperopes, 50% (1/2) of emmetropes, and 100% (4/4) of myopes met the targeted range. At 6 months, the MRSE for the hyperopic subgroup (n=5) was 0.33 D (±0.20 SD), the MRSE for the emmetropic subgroup (n=2) was −1.19 D (±0.19 SD), and the MRSE for the myopic subgroup (n=4) was −0.66 D (±0.36 SD).ConclusionBased on preliminary results and a small sample size, it seems that simultaneous PRK and KAMRA is effective and predictable. There are multiple advantages in performing simultaneous PRK and KAMRA including a shorter recovery time and less steroid use than the two surgeries performed separately.

Influence of the change in the shape of the corneal epithelium removal in postoperative PRK visual acuity.

Objective: To determine if the change in the shape of the corneal epithelial removal in photorefractive keratectomy (PRK), from circular to oval shape, modifies the recovery of the postoperative visual acuity (VA). Methods: Forty-three(43) patients subjected to bilateral simultaneous PRK were prospectively evaluated. Randomly for each patient, one eye underwent epithelial removal in circular shape and the other in oval shape. On the sixth day of postoperative period (D6) the follow items were recorded: the subjective comparative perception, informed by the patient, of the quality of vision between the eyes, the objective monocular VA and the appearance of the central corneal epithelial suture line. Results: With regard to subjective quality of vision perception, it was observed that 48.8% of patients did not realize the difference between the eyes, while 51.2% did (41.9% reported better quality of vision in the eye with the oval shape and 9.3% reported better vision in the eye with the circular shape). With regard to the VA (Snellen), the average in the oval shape of 0.62 was significantly higher (p < 0.001) than the circular shape of 0.53. As for the appearance of the epithelial suture line, in 64.3% of the cases there was a lower density of the suture line in the eyes submitted to the oval shape, 31.0% did not demonstrate difference and in 4.8% of eyes submitted to oval shape the suture line was denser. These results are due to the fact that in the oval shape the epithelial cells come from non-equidistant edges of the corneal periphery to the center and run across a smaller area, determining a smoother, sometimes off-center, epithelial suture line. Conclusion: The change in the shape of the corneal epithelial removal in photorefractive keratectomy (PRK), from circular to oval shape, determines a better recovery of the postoperative visual acuity (VA).

Simultaneous wavefront-guided photorefractive keratectomy and corneal collagen crosslinking after intrastromal corneal ring segment implantation for keratoconus

To study the results of simultaneous photorefractive keratectomy (PRK) and corneal collagen crosslinking (CXL) in keratoconus after previous intrastromal corneal ring segment (ICRS) implantation. Enaim Laser Center, Jerusalem, Israel. Case series. This study comprised patients with moderate keratoconus who had previous Intacs ICRS implantation with the Intralase laser at least 6 months before PRK-CXL. Wavefront-guided PRK and ultraviolet-A CXL were performed simultaneously. Refraction, uncorrected (UDVA) and corrected (CDVA) distance visual acuities, keratometry (K) values, endothelial cell count (ECC), pachymetry, corneal resistance factor (CRF), and corneal hysteresis (CH) were assessed 3, 6, and 12 months postoperatively. Twelve months after PRK-CXL, the mean decimal UDVA improved significantly from 0.20 ± 0.12 (SD) to 0.55 ± 0.15 (P<.01). The mean decimal CDVA improved from 0.58 ± 0.13 to 0.77 ± 0.17 (P=.01). The mean cylinder decreased from -3.60 ± 1.70 to -1.30 ± 1.10 diopters (D) (P<.001). The mean apex K decreased from 50.91 ± 5.50 D to 46.61 ± 4.52 D (P<.005). The other corneal parameters did not change significantly after treatment. No significant difference was found between the 6-month and 12-month results. No patient lost lines of CDVA. Mild haze remained in 11.1% of eyes 12 months after treatment. Simultaneous wavefront-guided PRK and CXL for keratoconus after ICRS implantation was safe and effective. It significantly improved the UDVA, CDVA, and central K value, and consequently the visual function, of patients with moderate keratoconus.

Long‐term results of simultaneous topo‐guided photorefractive keratectomy followed by corneal collagen cross‐linking for keratoconus

AbstractPurpose To present the long‐term results after simultaneous photorefractive keratectomy (PRK) followed by corneal collagen cross linking (CXL) for keratoconusMethods In this prospective case series, 26 patients (31 eyes) with progressive keratoconus were included. All patients underwent customized topography guided photorefractive keratectomy (PRK) immediately followed by corneal collagen cross linking with the use of riboflavin and ultraviolet‐A irradiation. Epithelium was removed by transepithelial phototherapeutic keratectomy (t‐PTK) in all casesResults Mean follow‐up was 19.53 +/‐ 3.97 months (range 12 to 25 months). Mean preoperative spherical equivalent (SE) was –2.3 +/‐ 2.8 diopters (D) while at the last follow up examination was significantly (p&lt;0.001) reduced to ‐1.08 +/‐ 2.41 D. LogMAR uncorrected (UDVA) and corrected distance visual acuity (CDVA) were significantly reduced by 0.46 and 0.084 LogMAR units, (p&lt;0.001) at the last follow up examination. Mean steep and flat keratometry readings were reduced by 2.35 D (p&lt;0.001) and 1.18 D (p=0.013) at the last follow‐up examinationConclusion Simultaneous topo‐guided PRK followed by CXL seems to be an effective and safe treatment without any complications in our series of keratoconic patients

Simultaneous Topography-Guided Photorefractive Keratectomy Followed by Corneal Collagen Cross-linking for Keratoconus

To present the long-term results after simultaneous photorefractive keratectomy followed by corneal collagen cross-linking for keratoconus. Prospective, interventional, consecutive case series. In this study, 26 patients (31 eyes) with progressive keratoconus were included. All patients underwent customized topography-guided photorefractive keratectomy immediately followed by corneal collagen cross-linking with the use of riboflavin and ultraviolet A irradiation. Epithelium was removed by transepithelial phototherapeutic keratectomy in all cases. Mean follow-up was 19.53 ± 3.97 months (range, 12 to 25 months). Mean preoperative spherical equivalent was -2.3 ± 2.8 diopters (D), whereas at the last follow-up examination, it was significantly (P < .001) reduced to -1.08 ± 2.41 D. Logarithm of the minimal angle of resolution uncorrected and best-corrected visual acuity were reduced significantly by 0.46 and 0.084 (P < .001), respectively, at the last follow-up examination. Finally, mean steep and flat keratometry readings were reduced by 2.35 (P < .001) and 1.18 (P = .013) at the last follow-up examination. Simultaneous photorefractive keratectomy followed by corneal collagen cross-linking seems to be a promising treatment alternative in our series of keratoconic patients.

Posterior Linear Stromal Haze Formation after Simultaneous Photorefractive Keratectomy followed by Corneal Collagen Cross-linking

To report the development of posterior linear stromal haze after simultaneous photorefractive keratectomy (PRK) followed by corneal collagen cross-linking (CXL). Combined simultaneous customized PRK followed by corneal collagen cross-linking was performed in 23 patients (28 eyes) with keratoconus. Corneas were examined biomicroscopically and by means of confocal microscopy before surgery and 1, 3, 6, 9, and 12 months after surgery. Posterior linear stromal haze was observed clinically (slit lamp biomicroscopy) one month after surgery in 13 of 28 eyes (46.42%). No corneal edema or anterior haze formation was evident. Confocal microscopy revealed in those 13 eyes a hyperreflective area at the level of the posterior stroma 1 month after combined treatment. Both slit lamp examination and corneal confocal microscopy follow-up demonstrated a gradual anterior movement and a decrease in reflectance of this finding. At 12 months this posterior linear stromal haze, despite its anterior movement and decreased density, did not completely disappear at slit lamp and confocal microscopy analysis. Posterior linear stromal haze formation may appear after simultaneous PRK followed by CXL in patients with keratoconus. This finding seems to gradually become less dense and slowly moves toward the anterior stroma.

Simultaneous Topography-guided PRK Followed by Corneal Collagen Cross-Linking for Keratoconus

To present the results after simultaneous photorefractive keratectomy (PRK) followed by corneal collagen cross-linking (CXL) for progressive keratoconus. Twelve patients (14 eyes) with progressive keratoconus were prospectively treated with customized topography-guided PRK with the Pulzar Z1 (wavelength 213 nm, CustomVis) immediately followed by corneal collagen CXL with the use of riboflavin and ultraviolet A irradiation. Mean follow-up was 10.69+/-5.95 months (range: 3 to 16 months). Mean preoperative spherical equivalent refraction (SE) was -3.03+/-3.23 diopters (D) and defocus was 4.67+/-3.29 D; at last follow-up SE and defocus were statistically significantly reduced to -1.29+/-2.05 D and 3.04+/-2.53 D, respectively (P<.01). Preoperative mean (logMAR) uncorrected visual acuity was 0.99+/-0.81 and best spectacle-corrected visual acuity was 0.21+/-0.19, which improved postoperatively to 0.16+/-0.15 and 0.11+/-0.15, respectively. The mean steepest keratometry was reduced from 48.20+/-3.40 D preoperatively to 45.13+/-1.80 D at last follow-up. Simultaneous PRK followed by CXL seems to be a promising treatment capable of offering functional vision in patients with keratoconus.

Simultaneous topo‐guided photorefractive keratectomy (PRK) followed by collagen cross‐linking (CXL) for the treatment of keratoconus

Abstract Purpose To present the results after simultaneous topoguided Photorefractive Keratectomy (PRK) followed by corneal collagen cross linking with Riboflavin/Ultraviolet – A irradiation (CXL) for the treatment of keratoconus. Methods In this prospective case series, 22 patients (27 eyes) with progressive keratoconus participated. All patients underwent customized topography guided photorefractive keratectomy (PRK) immediately followed by corneal collagen cross linking with the use of riboflavin and ultraviolet – A irradiation. Results Mean follow up was 10.72+5.98 months (range from 3 to 19 months). Mean preoperative spherical equivalent (SE) (diopters, D) and defocus were –3.03 ± 3.23D and 4.67±3.29D while at the last follow up examination were significantly reduced to ‐1.29 ± 2.05D and 3.04±2.53D, respectively. Preoperative mean (LogMAR) Uncorrected Visual Acuity (UCVA) and Best Spectacle Corrected Visual Acuity (BSCVA) were 0.99±0.81 and 0.21±0.19 while at the last follow up examination were improved to 0.16±0.15 and 0.11±0.15 respectively. Mean preoperative steepest meridian keratometry from 48.2±3.4D was reduced to 45.13±1.8D at the last follow up examination. Conclusion Simultaneous PRK followed by CXL seems to be a promising treatment capable of offering patients a functional vision and halting progression of the ectatic disorder. Longer follow up and larger case series are necessary in order to fully evaluate this new innovative combined procedure.

Management of pellucid marginal corneal degeneration with simultaneous customized photorefractive keratectomy and collagen crosslinking

A 34-year-old woman had simultaneous photorefractive keratectomy and corneal collagen crosslinking with riboflavin-ultraviolet-A irradiation for the treatment of progressive pellucid marginal corneal degeneration in both eyes. No intraoperative or early postoperative complications occurred. Twelve months postoperatively, the uncorrected visual acuity was assessed at 20/40 in both eyes compared with counting fingers preoperatively. The corrected visual acuity also improved from 20/50 and 20/63 to 20/25 and 20/32 in the right eye and left eye, respectively. Corneal topography revealed a significant improvement in both eyes. Despite the encouraging results, longer follow-up is necessary to confirm the stability of the results.

Photorefractive Keratectomy in a Patient with Epithelial Basement Membrane Dystrophy

Purpose: To report a case of excimer laser photorefractive keratectomy (PRK) in a patient with epithelial basement membrane dystrophy (EBMD). Methods: Interventional case report. Results: A 36-year-old male with clinical manifestations of EBMD underwent bilateral, simultaneous PRK for low myopia correction. A delay (up to 17 days) in the epithelial healing process with unstable epithelium was observed. During the first three postoperative months a visually significant subepithelial haze was developed in both eyes. One year postoperative, an improvement in haze formation and visual acuity in both eyes was found. Conclusions: PRK in patients with EBMD could result in favorable refractive and clinical outcome.

Rehabilitation time after simultaneous bilateral photorefractive keratectomy for low to moderate myopia

To evaluate the visual acuity rehabilitation time after simultaneous bilateral photorefractive keratectomy (PRK) using a flying small spot laser. Eye Tech Medical Laser, Tel Aviv, Israel. In this prospective interventional nonrandomized clinical trial, 42 consecutive eyes (21 patients) with myopia ranging from -0.75 to -5.50 diopters (D) (mean -2.75 D +/- 1.18 [SD]) and astigmatism up to -2.75 D (mean -0.64 +/- 0.55 D) were treated with bilateral simultaneous PRK using the ESIRIS excimer laser (Schwind). Main outcome measures were uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), and manifest refraction up to 12 weeks after surgery. Both eyes of each patient were examined at the same follow-up after initial treatment. Within 2 weeks and 1 month of the laser procedure, the UCVA was at least 20/40 in 1 eye in 85.7% of patients (18 patients) and 100% of patients (21 patients), respectively. After 2 weeks, UCVA was at least 20/20, 20/25, and 20/40 in 7.1%, 40.5%, and 80.9% of eyes. The final mean manifest spherical equivalent 12 weeks post laser treatment was -0.10 +/- 0.26 D, with a mean sphere of +0.02 +/- 0.22 D and a mean cylinder of -0.24 +/- 0.37 D. No eye had a BCVA loss during the follow-up. Simultaneous bilateral PRK using a flying small spot excimer laser for low to moderate myopia allowed most patients to return to most daily tasks in a couple of weeks without compromising safety.

Photorefractive keratectomy using a scanning-slit laser, rotary epithelial brush, and chilled balanced salt solution

Purpose To evaluate photorefractive keratectomy (PRK) using a scanning-slit excimer laser combined with removal of the epithelium using a rotary epithelial brush and prebrush and postoperative cooling of the cornea with chilled balanced salt solution (BSS®). Setting Johannesburg Laser Center, Johannesburg, South Africa. Methods In a prospective study, 500 consecutive eyes with myopia ranging from 1.00 to 12.75 diopters (D) and astigmatism up to 6.50 D were treated with PRK using a Nidek EC-5000 scanning-slit excimer laser, removal of the epithelium with a rotary epithelial brush, and prebrush and postlaser cooling of the cornea with chilled BSS (4°C to 6°C). The mean follow-up was 9.32 months (range 1 week to 39 months). Bilateral simultaneous PRK was performed in 238 patients (95.2% of eyes). Results After 1 week, uncorrected visual acuity was 20/20, 20/25, 20/30, 20/40, 20/60, and 20/80 in 9.80%, 38.60%, 68.20%, 89.40%, 97.80%, and 97.20% of eyes. After 6 months, in 405 eyes, it was 20/15, 20/20, 20/25, 20/30, and 20/40 in 9.38%, 69.88%, 91.11%, 94.81%, and 98.52%. After 12 months, in 222 eyes, it was 20/15, 20/20, 20/25, 20/30, and 20/40 in 6.76%, 68.92%, 83.78%, 91.89%, and 97.30%. After 18 months, in 95 eyes, it was 20/15, 20/20, 20/25, 20/30, and 20/40 in 6.32%, 69.47%, 88.42%, 91.58%, and 96.84%. Six eyes (1.20%) required retreatment. Conclusions Scanning-slit laser PRK after rotary epithelial scrubbing and prescrub and postlaser cooling allows accurate correction of myopia and astigmatism with minimal regression.