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Purpose: The aim of this study was to present the 3-year outcomes after simultaneous transepithelial phototherapeutic keratectomy (t-PTK) and conventional photorefractive keratectomy (PRK) followed by corneal crosslinking (CXL) for keratoconus., Methods: In this prospective, interventional case series, patients with progressive keratoconus underwent simultaneous t-PTK and conventional PRK followed by CXL (Cretan protocol plus). Visual, refractive, and topographic outcomes were evaluated along with endothelial cell density (ECD) preoperatively and at 1, 2, and 3 years postoperatively., Results: Twenty-two patients (31 eyes) were enrolled. No intraoperative or postoperative complications were observed in any of the patients. Logarithm of the minimum angle of resolution (logMAR) mean uncorrected and mean corrected distance visual acuity improved from 0.81 ± 0.40 and 0.18 ± 0.21 preoperatively to 0.38 ± 0.33 ( P < 0.001) and 0.06 ± 0.12 ( P < 0.001) at 3-year follow-up. Mean spherical equivalent improved from -5.39 ± 3.89 diopters (D) preoperatively to -2.29 ± 2.65 D ( P < 0.001) at 3 years postoperatively. Mean corneal astigmatism reduced from -4.70 ± 2.86 D preoperatively to -3.55 ± 2.45 D ( P = 0.001) at 3 years postoperatively. No ECD alterations were observed throughout the 3-year follow-up ( P > 0.05)., Conclusions: Simultaneous t-PTK and conventional PRK followed by CXL seems to be an effective and safe treatment for progressive keratoconus over 3-year follow-up., Competing Interests: The authors have no funding or conflicts of interest to disclose., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

Purpose: To compare the long-term outcomes of corneal cross-linking (CXL) for the treatment of keratoconus using two different techniques for epithelial removal: transepithelial phototherapeutic keratectomy (t-PTK) and mechanical epithelial debridement., Methods: In this prospective, comparative, interventional case series, 26 patients (30 eyes) with progressive keratoconus underwent CXL treatment. Fifteen eyes (13 patients) underwent epithelial removal with t-PTK (Cretan protocol) and 15 eyes (13 patients) underwent mechanical epithelial debridement (Dresden protocol) during CXL. Visual, refractive, and keratometric outcomes were evaluated preoperatively and at 1, 2, 3, and 4 years postoperatively., Results: No intraoperative or postoperative complications were observed in any of the patients. In the Cretan protocol group, mean uncorrected (UDVA) and corrected (CDVA) visual acuity improved from 0.99 ± 0.42 and 0.33 ± 0.28 logMAR preoperatively to 0.75 ± 0.32 (P = .018) and 0.21 ± 0.16 (P = .024) logMAR at 4 years postoperatively, respectively. In the Dresden protocol group, mean UDVA improved from 0.83 ± 0.47 logMAR preoperatively to 0.63 ± 0.40 logMAR (P = .033) at 4 years postoperatively, whereas mean CDVA did not demonstrate a statistically significant improvement postoperatively (P > .05). In the Cretan protocol group, mean corneal astigmatism improved from -6.19 ± 4.54 diopters (D) preoperatively to -4.68 ± 3.10 D (P = .041) at last follow-up, whereas in the Dresden protocol group there was no statistically significant difference postoperatively (P > .05)., Conclusions: Epithelial removal with t-PTK during CXL (Cretan protocol) resulted in better visual, refractive, and keratometric outcomes compared with mechanical epithelial debridement over a long-term follow-up. [J Refract Surg. 2019;35(10):650-655.]., (Copyright 2019, SLACK Incorporated.)

Purpose: To evaluate the visual, refractive, and topographic outcomes after combined transepithelial phototherapeutic keratectomy (PTK) and conventional photorefractive keratectomy (PRK) followed simultaneously by corneal crosslinking (CXL) for keratoconus., Setting: Vardinoyiannion Eye Institute of Crete, Faculty of Medicine, University of Crete, Heraklion, Crete, Greece., Design: Prospective case series., Methods: Patients with progressive keratoconus had simultaneous conventional PRK followed by CXL; the corneal epithelium was removed using transepithelial PTK (Cretan protocol plus). The visual, refractive, and topographic outcomes and the endothelial cell density (ECD) were evaluated preoperatively and 1, 3, 6, and 12 months postoperatively., Results: Forty-three patients (55 eyes) were enrolled. The mean uncorrected and corrected distance visual acuities improved significantly from 0.98 ± 0.63 (SD) logarithm of minimum angle of resolution (logMAR) and 0.20 ± 0.23 logMAR preoperatively to 0.39 ± 0.35 logMAR (P < .001) and 0.08 ± 0.16 logMAR (P < .001) 12 months postoperatively, respectively. The mean spherical equivalent improved significantly from -4.67 ± 4.00 diopters (D) preoperatively to -2.24 ± 2.81 D (P < .001) at 12 months. The mean steep keratometry (K) and flat keratometry readings decreased significantly from 50.30 ± 5.00 D and 45.62 ± 3.10 D preoperatively to 46.27 ± 3.90 D (P < .001) and 43.46 ± 3.00 D (P < .001) 12 months postoperatively, respectively. No ECD alterations were observed throughout the follow-up (P > .05)., Conclusion: Combined transepithelial PTK and conventional PRK followed simultaneously by CXL was effective in corneal stabilization and vision improvement in keratoconic patients., (Copyright © 2017 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.)

Purpose: To present the long-term results of combined transepithelial phototherapeutic keratectomy (PTK) and corneal collagen crosslinking (CXL) for keratoconus., Setting: Vardinoyiannion Eye Institute of Crete, University of Crete, Heraklion, Crete, Greece., Design: Prospective case series., Methods: Patients with progressive keratoconus had combined transepithelial PTK and CXL (Cretan protocol). Visual and refractive outcomes and the endothelial cell density (ECD) were evaluated preoperatively and postoperatively., Results: Twenty patients (23 eyes) were enrolled; postoperatively 23 eyes were evaluated at 1 and 2 years, 11 at 3 years, and 7 at 4 years. The mean follow-up was 33.83 months±10.82 (SD) (range 24 to 56 months). No intraoperative or postoperative complications occurred. The mean uncorrected distance visual acuity improved significantly from 0.99±0.57 logMAR preoperatively to 0.61±0.36 logMAR at the last follow-up (P<.001) and the mean corrected distance visual acuity, from 0.27±0.24 logMAR to 0.17±0.14 logMAR (P=.018), respectively. The mean steep and mean flat keratometry readings decreased significantly from 53.39±7.14 diopters (D) and 47.17±4.87 D, respectively, preoperatively to 49.99±4.36 D (P<.001) and 45.47±2.95 D (P=.002), respectively, at the last follow-up. The mean corneal astigmatism improved significantly from -6.27±4.19 D preoperatively to -4.52±2.80 D (P<.001) at the last follow-up. No significant ECD alterations occurred (P>.05)., Conclusion: Combined transepithelial PTK and CXL was effective and safe in keratoconic patients over a long-term follow-up., Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned., (Copyright © 2014 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.)

Purpose: To present the results after simultaneous conventional photorefractive keratectomy combined with corneal collagen cross-linking for pellucid marginal corneal degeneration., Methods: In this prospective, interventional case series, 6 patients (8 eyes) with pellucid marginal corneal degeneration were enrolled. All patients underwent simultaneous conventional photorefractive keratectomy combined with corneal collagen cross-linking; corneal epithelium was removed by transepithelial phototherapeutic keratectomy during treatment (Cretan protocol plus conventional photorefractive keratectomy). Visual and refractive outcomes were evaluated along with endothelial cell density preoperatively and at 1, 3, 6, and 12 months postoperatively., Results: No intraoperative or postoperative complications were observed in any of the patients. LogMAR mean uncorrected distance visual acuity improved significantly from 1.05 ± 0.33 preoperatively to 0.41 ± 0.27 (P = .018) at 12 months postoperatively. Mean corrected distance visual acuity did not change significantly (P > .05) postoperatively. Mean spherical equivalent improved significantly from -3.52 ± 2.29 diopters preoperatively to -1.57 ± 1.76 diopters (P = .028) at last follow-up. Mean corneal astigmatism was significantly reduced from -6.83 ± 2.33 diopters preoperatively to -4.71 ± 1.89 diopters (P = .018) at the last follow-up. No endothelial cell density alterations were observed throughout the follow-up period (P > .05)., Conclusions: Simultaneous conventional photorefractive keratectomy combined with corneal collagen cross-linking seems to be an effective, safe, and promising treatment for the management of pellucid marginal corneal degeneration., (Copyright 2014, SLACK Incorporated.)

Purpose: To compare the visual and refractive outcomes and the corneal structural changes in myopic patients after surface refractive treatments (ie, photorefractive keratectomy [PRK] with adjuvant mitomycin-C [MMC] and epithelial laser in situ keratomileusis [epi-LASIK])., Setting: University of Crete, Heraklion, Crete, Greece., Design: Prospective comparative case series., Methods: One eye of consecutive myopic patients was randomly assigned to PRK-MMC, and the fellow eye was treated with epi-LASIK. Visual and refractive outcomes and corneal confocal microscopy findings were evaluated. All patients were examined preoperatively and 1, 3, 6, 12, and 24 months postoperatively., Results: Twenty-six eyes (13 patients) were included. The mean follow-up was 2.47 years ± 0.35 (SD) (range 1.64 to 2.93 years). In the PRK-MMC group, the mean preoperative spherical equivalent refraction was -3.84 ± 1.59 diopters (D) (range -1.5 to -8.7 D) and -0.21 ± 0.44 D (range -0.5 to 1.0 D) at the last follow-up and in the epi-LASIK group, -3.91 ± 1.48 D (range -1.5 to -8.5 D) and -0.18 ± 0.36 (range +0.5 to -0.5 D), respectively. Qualitative analysis of the subepithelial nerve plexus, haze development, and keratocyte distribution were similar in the 2 groups. There was no statistically significant difference in endothelial cell density between the groups throughout the follow-up (P>.05)., Conclusion: Epithelial LASIK and PRK-MMC gave similar visual, refractive, and corneal structural outcomes in patients with myopia for up to 2 years postoperatively., Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned., (Copyright © 2013 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.)

Purpose: To evaluate the outcomes of refractive surgery in patients with topographic superior corneal steepening., Methods: This retrospective, noncomparative, interventional, clinical study included 16 patients (29 eyes) with persistent superior corneal steepening as a variation of corneal curvature (inferior to superior topographic corneal difference of at least 1.00 diopter [D] at a 3-mm zone) not related to any underlying disease or condition who underwent corneal refractive surgery. Refractive, keratometric, and visual outcomes were evaluated preoperatively and at 1, 3, 6, 12, and 24 months postoperatively., Results: Twenty-two eyes underwent photorefractive keratectomy and 7 eyes underwent LASIK. Mean follow-up was 27.38±2.37 months (range: 25 to 32 months). Mean preoperative inferior to superior keratometric difference was 1.61±0.36 D (range: 1.20 to 2.63 D). Mean preoperative spherical equivalent refraction was -4.45±1.66 D (range: -2.25 to -8.00 D), which decreased to -0.09±0.61 D (range: +0.75 to -1.38 D) (P<.05) at last follow-up. Mean preoperative topographic corneal astigmatism was 1.44±0.79 D (range: 0.52 to 3.83 D), which decreased to 0.66±0.39 D (P<.05) 3 months postoperatively and remained stable during follow-up (P<.54). Mean preoperative uncorrected distance visual acuity and corrected distance visual acuity in logMAR units were 1.57±0.62 and 0.02±0.06, respectively, which improved at last follow-up to 0.00±0.05 and -0.02±0.04, respectively. No intra- or postoperative complications were noted; specifically, no patients developed postoperative ectasia., Conclusions: Corneal refractive surgery in patients with isolated topographic superior corneal steepening provided acceptable refractive and visual outcomes without any intra- or postoperative complications. Diligence is required to screen for the potential of ectatic corneal disorders in this population. Photorefractive keratectomy may be a safer option for these patients than LASIK., (Copyright 2012, SLACK Incorporated.)

Purpose: To compare the efficacy of 2 types of silicone hydrogel bandage contact lenses with high oxygen transmissibility after photorefractive keratectomy (PRK)., Setting: Institute of Vision and Optics, Faculty of Medicine, University of Crete, Heraklion, Crete, Greece., Methods: In this prospective study, 1 eye of patients having bilateral PRK was randomly fitted with a bandage contact lens of lotrafilcon A (Night & Day) and the fellow eye, with a bandage contact lens of lotrafilcon B (O(2)Optix). The patients and the examiner were masked to which bandage contact lens type was in which eye. Patients were examined on the day of surgery and 1, 3, and 5 days postoperatively. Postoperative examinations included uncorrected distance visual acuity and slitlamp biomicroscopy to assess epithelial defect size. Subjective evaluation of pain and vision was recorded 1, 2, 3, and 4 days postoperatively., Results: The study enrolled 44 patients (88 eyes). The mean epithelial defect size immediately after surgery was 47.0 mm(2) with both types of bandage contact lenses. There was no statistically significant difference in epithelial defect size between the 2 lenses at any postoperative visit. Three days postoperatively, reepithelialization was complete in 75.0% of eyes in the lotrafilcon A group and 72.7% of the eyes in the lotrafilcon B group., Conclusion: There were no differences in corneal reepithelialization or subjective measurements after PRK between the 2 types of silicone hydrogel bandage contact lenses.

Purpose: To present the results after simultaneous photorefractive keratectomy (PRK) followed by corneal collagen cross-linking (CXL) for progressive keratoconus., Methods: 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., Results: 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., Conclusions: Simultaneous PRK followed by CXL seems to be a promising treatment capable of offering functional vision in patients with keratoconus., (Copyright 2009, SLACK Incorporated.)

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.

Purpose: To compare the refractive outcomes after photorefractive keratectomy (PRK) for low to moderate myopic corrections using 2 excimer lasers with different repetition rates (200 Hz and 400 Hz)., Setting: University refractive surgery center., Methods: This retrospective study included all consecutive patients who underwent PRK using the 200 Hz or the 400 Hz Allegretto laser platform (WaveLight Laser Technologie AG). Thirty-five patients (70 eyes) and 29 patients (58 eyes) had PRK with the 200 Hz platform and the 400 Hz platform, respectively, using the same surgical technique., Results: The mean follow-up was 13.22 months +/- 1.16 (SD) (range 11 to 15 months). No intraoperative or early postoperative (eg, late reepithelialization) complications were found in either group. At 1 year, 66 eyes (94.2%) in the 200 Hz group and 56 eyes (96.6%) in the 400 Hz group were within +/-1.00 diopter of the attempted correction. At 3 months, 20 eyes (29%) in the 200 Hz group and 27 eyes (46%) in the 400 Hz group had mild or moderate corneal haze (P = .03). These corneas showed progressive clearing over subsequent months without statistically significant differences in haze formation between the 2 groups. Twelve months after PRK, all corneas in both groups were clear., Conclusion: Photorefractive keratectomy for the treatment of low to moderate refractive errors using a 200 Hz or 400 Hz excimer laser gave comparable results.

Purpose: To compare histopathologic changes after photorefractive keratectomy (PRK) for myopia using either a solid state laser (SSL) at 213 nm or an excimer laser (EL) at 193 nm in an experimental model., Methods: Forty pigmented rabbits (80 eyes) underwent myopic PRK for the correction of 6 D. Photoablation was randomly assigned, with a solid state laser used in one eye and an EL in the fellow eye. Rabbits were killed immediately after ablation (n = 10) or at 7 days (n = 10), 1 month (n = 8), 3 months (n = 6), or 12 months (n = 6) after surgery. Corneal tissue was preserved for light microscopy and transmission electron microscopy at all postoperative intervals., Results: All eyes reepithelialized in 1 week with no early or late postoperative complication. Immediately after ablation, light, scanning, and transmission electron microscopy revealed relatively smooth ablation surfaces in both groups. Seven days after surgery, epithelium in the SSL specimens appeared thinner than in the EL specimens. Activated keratocytes were observed adjacent to the epithelium in both groups, whereas endothelial cells demonstrated normal morphology. At 1, 3, and 12 months after surgery, tissue appearance of all corneal layers was similar in both groups., Conclusions: PRK in rabbits using ultraviolet SSL and EL revealed similar histopathologic findings up to 1 year after surgery.

Purpose: To evaluate possible changes of the ocular rigidity coefficient in vivo after photorefractive keratectomy (PRK) in a series of rabbit eyes, using an invasive ocular rigidity measurement device., Methods: Sixteen eyes of 8 rabbits were used in this study. One eye from each rabbit underwent PRK for -10.00 diopters (D) in a 5-mm optical zone (92 microm) while the fellow eye served as the control. Five weeks later, the rabbits were examined under general anesthesia. The pressure-volume relationship and the ocular rigidity coefficient were determined in all 16 eyes, by injecting 200 microL of saline solution (in increments of 4.5 microL) through the limbus into the anterior chamber, while the intraocular pressure (IOP) was continually monitored with a transducer, up to a maximum limit of 40 mmHg. Data within an IOP range of 10 to 40 mmHg were used to calculate the ocular rigidity coefficient., Results: The preoperative central corneal thickness was comparable (P = .73, paired t test) in the pre-PRK eyes (mean: 347.5 +/- 17.11 microm) and control eyes (mean: 349.1 +/- 17.46 microm). No statistically significant difference was noted in measured ocular rigidity coefficient between eyes treated with PRK and control eyes (mean rigidity coefficient: 0.42 +/- 0.12 mmHg/microL [range: 0.23 to 0.56] and 0.47 +/- 0.12 mmHg/microL [range: 0.28 to 0.62], respectively, with 95% confidence interval of the difference, lower: -0.10 to upper: 0.015, P = .121)., Conclusions: Photorefractive keratectomy did not significantly alter ocular rigidity measurements in this experimental model.

Purpose: To evaluate whether photorefractive keratectomy (PRK) for moderate myopia using a solid-state laser with a wavelength of 213 nm alters the corneal endothelial cell density., Setting: University refractive surgery center., Methods: The corneal endothelium was analyzed preoperatively and 1, 6, and 12 months postoperatively using corneal confocal microscopy (modified HRT II with a Rostock Cornea Module, Heidelberg Engineering) in 60 eyes (30 patients). Patients were randomized to have myopic PRK using a 213 nm wavelength solid-state laser (study group) or a conventional 193 nm wavelength excimer laser (control group). Three endothelial images were acquired in each of 30 preoperative normal eyes to evaluate the repeatability of endothelial cell density measurements. Repeated-measures analysis of variance was used to compare the variations in endothelial cell density between the 2 lasers and the changes in endothelial cell density over time., Results: There were no statistically significant differences in sex, age, corneal pachymetry, attempted correction, preoperative endothelial cell density, or postoperative refractive outcomes (uncorrected visual acuity, best spectacle-corrected visual acuity, and spherical equivalent refraction) between the 2 groups (P>.05). The coefficient of repeatability of endothelial cell density was 131 cells/mm(2). The measured endothelial cell count per 1.0 mm(2) did not significantly change up to 1 year postoperatively in either group (both P>.05). No statistically significant difference was found between the 2 groups in any postoperative interval (P>.05)., Conclusion: Photorefractive keratectomy for moderate myopia using a 213 nm wavelength solid-state laser or a conventional 193 nm wavelength excimer laser did not significantly affect corneal endothelial density during the 1-year postoperative period.

Purpose: To study the long-term results of photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK) in low to moderate myopic corrections using the Pulzar Z1 system (CustomVis), a 213 nm wavelength solid-state laser., Setting: University refractive surgery center., Methods: This prospective noncomparative case series comprised 20 patients (40 eyes) who had refractive surgery using the Pulzar Z1 laser system. Manifest refraction, uncorrected visual acuity, best spectacle-corrected visual acuity (BSCVA), safety, predictability, stability, and confocal microscopy images were evaluated., Results: Ten patients (20 eyes) had PRK and 10 patients (20 eyes) had LASIK. The mean follow-up was 13.9 months +/- 1.1 (SD) (range 12 to 17 months) and 14.6 +/- 1.2 months (range 12 to 18 months) in the PRK group and LASIK group, respectively. No eye lost a line of Snellen BSCVA during the follow-up period; 2 eyes (10%) gained 2 Snellen lines. There was a statistically significant decrease in spherical equivalent manifest refraction postoperatively in both groups (P<.05). Refractive stability was obtained during the first postoperative month and remained stable during the follow-up period, with no significant changes between any interval in both groups (P>.05). At the last follow-up, 95% of all eyes were within +/-1.00 diopter of emmetropia. No late postoperative complications were observed., Conclusion: Refractive surgery using the Pulzar Z1 213 nm wavelength solid-state laser was a safe, effective procedure in the treatment of low to moderate myopia.

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.

Purpose: The aim of the current study was to control the hypothetical effects of decreased laser energy delivered to the peripheral cornea during phototherapeutic keratectomy (PTK) and provide quantitative calculation of induced low and high order aberrations., Methods: We employed a model eye to simulate the refractive effect of homogeneous laser corneal irradiation, as in PTK, for different laser fluences (range 125 to 225 mJ/cm2) and treatment depths up to 200 microm., Results: The hyperopic shift induced by the relatively lower energy delivered at the peripheral ablation zone during PTK was proportional to the treatment depth and inversely proportional to the energy fluence. The hyperopic shift calculated using the above ablation parameters was lower compared to previously reported clinical results. Higher order wavefront aberration (total root mean square) changes were of minimal significance for treatment depths up to 200 microm., Conclusions: After PTK, a hyperopic shift cannot be attributed to the energy delivery method alone. Modification of laser energy delivery algorithms may only minimize PTK-induced hyperopia.

Background: To compare the corneal healing response between conventional and phototherapeutic keratectomy through a masking agent, in rabbit corneas., Methods: 24 adult rabbits underwent phototherapeutic keratectomy. Animals were divided in two groups: 12 received photoablation through a masking agent (PALM gel) and the remaining 12 received conventional phototherapeutic keratectomy of equal depth and served as control. Light and transmission electron microscopy was performed in specimens of both groups obtained: immediately after, four hours, one week, one, three and six months after treatment., Results: Reepitheliazation was complete within five days in all eyes. Light and transmission electron microscopy did not reveal any differences of the healing process in the experimental eyes compared to the controls., Conclusion: Photoablation through the PALM technique did not result any evident alterations of the reepithelisation and stromal healing process.

Purpose. To study the long term refractive and visual outcomes of photorefractive keratectomy (PRK) with intraoperative application of mitomycin C (MMC). Methods. This study included 37 eyes who received myopic PRK; after photoablation, a sponge soaked in 0.02% MMC solution was applied in all corneas for 2 minutes. Efficacy, safety, predictability, and stability of PRK MMC were evaluated. Endothelial cell density was evaluated at the last postoperative interval. Results. Mean preoperative spherical equivalent (SEQ) was -6.03 ± 1.87 D (diopters) and reduced to -0.09 ± 0.53 D at the last postoperative examination. Mean followup was 44.73 ± 18.24 months. All the eyes were in the ±1.00 D of attempted versus achieved SEQ at the one-year follow-up interval. Furthermore, 95% of the eyes did not lose lines or gained 1 to 2 lines of CDVA, while 5% lost 1 line. At the third postoperative month, 89% of the eyes either were clear or had trace haze, while 4 eyes had mild haze; by the 12-month postoperative interval, none of the eyes demonstrated haze. Mean endothelial cell density (ECD) at the last postoperative interval was 2658 ± 153 cells/mm². Conclusions. PRK, with intraoperative use of MMC, demonstrates stable refractive and visual outcomes up to 44 months after surgery. [ABSTRACT FROM AUTHOR]