Therapeutic visual rehabilitation in a patient with high hyperopia and flat cornea years after radial keratotomy.

A 51-year-old man was referred for refractive surgery evaluation. Spectacle dependence and poor visual quality in both eyes was his chief complaint. He cannot tolerate contact lenses. Corrected distance visual acuity (CDVA) was 20/40 in both eyes. Manifest refraction was +5.25 -2.25 @ 90 (20/40) in the right eye and +6.25 -2.25 @ 105 (20/40) in the left eye. The patient had a history of radial keratotomy (RK) almost 30 years ago in both eyes and at the slitlamp presented 8 RK incisions, proportionally spaced between one another. All incisions were closed, and there were no relevant signs of scarring. The patient denied any history of ocular trauma, systemic disease, or medications. Corneal topography with different technologies revealed an irregular pattern with marked central flattening in both eyes, with some points below 30 diopters (D) (Supplemental Figures 1 and 2, available at http://links.lww.com/JRS/A862 and http://links.lww.com/JRS/A863, respectively). There were no signs of cataract, and fundus examination was normal. Optical coherence tomography (OCT) of the right eye revealed a more homogeneous thickness pattern, little variation between the thinnest and thickest areas, and adequate transparency (Figure 1JOURNAL/jcrs/04.03/02158034-202306000-00018/figure1/v/2023-05-31T172126Z/r/image-tiff). In the left eye, there is wide variability between the thinnest and thickest stromal points, with annular thinning and central thickening (Figure 2JOURNAL/jcrs/04.03/02158034-202306000-00018/figure2/v/2023-05-31T172126Z/r/image-tiff). Both eyes show marked epithelial irregularity. Considering this patient's current ocular status, how would you reach visual rehabilitation? Because he is contact lens intolerant, would you consider surface ablation, for example, photorefractive keratectomy (PRK) with mitomycin-C (MMC)? If that were the case, would you think of an optimized or a topography-guided (TG) treatment? Would you immediately consider a corneal transplant option? Would you instead consider a more conservative approach? Which one and why?

Transepithelial Surface Ablation With Mitomycin C for the Treatment of Chronic Central Corneal Scars Following Adenoviral Keratoconjunctivitis.

PURPOSE: To assess visual and refractive outcomes and recurrence rates of subepithelial infiltrates after corneal surface ablation with mitomycin C (MMC) 0.02% for the treatment of chronic corneal scars following epidemic keratoconjunctivitis and to compare these results with a control group receiving only medical treatment. METHODS: This was a retrospective case series enrolling patients with central corneal scars following epidemic keratoconjunctivitis. Patients were divided into two groups: (1) control with clinical follow-up and refractive correction with glasses or rigid gas-permeable contact lenses when necessary and (2) transepithelial phototherapeutic keratectomy (PTK) with MMC 0.02%, combined with photorefractive keratectomy (PRK) in selected cases (treatment group). Signs and symptoms, corrected distance visual acuity (CDVA) in logMAR units, manifest and cycloplegic refraction, and depth of the corneal opacities were assessed. RESULTS: Thirty-five eyes of 27 patients (11 men [40.7%] and 16 women [59.3%]) were enrolled, with a mean follow-up of 54.4 ± 19.7 and 27.5 ± 22.8 months in the control and treatment groups, respectively. Mean improvement in CDVA was 0.13 ± 0.17 logMAR (P = .007) in the control group and 0.29 ± 0.24 logMAR (P = .001) in the treatment group. Intergroup comparison showed a greater improvement in the treatment group (P = .041). Mean hyperopic shift induced in the treatment group was +0.46 ± 1.20 diopters. The recurrence rate of subepithelial infiltrates was 77.7% in the control group and 11.7% in the treatment group throughout the follow-up (54.4 ± 19.7 and 27.5 ± 22.8 months, respectively). CONCLUSIONS: Corneal surface ablation with MMC 0.02% was efficient in treating corneal scars following adenoviral epidemic keratoconjunctivitis, with greater visual improvement in comparison to clinical treatment and a decreased rate of infiltrate recurrence. [J Refract Surg. 2020;36(1):55-61.].

Haze and Visual Acuity Loss After Sequential Photorefractive Keratectomy and Corneal Cross-linking for Keratoconus.

PURPOSE: To investigate the results after photorefractive keratectomy (PRK) followed immediately by standard 30-minute corneal cross-linking (CXL) for keratoconus. METHODS: This retrospective study included 26 eyes of 16 patients with keratoconus. Uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), manifest refraction spherical equivalent (SE) and cylinder, apical keratometry, corneal higher order aberrations (HOAs), and corneal haze were evaluated. RESULTS: Mean follow-up was 32 ± 8 months (range: 19 to 50 months) and mean patient age was 31 ± 5 years (range: 24 to 40 years). Mean UDVA improved significantly from 0.80 ± 0.39 to 0.32 ± 0.36 logMAR after surgery (P < .001), but the mean CDVA worsened significantly from 0.07 ± 0.09 to 0.15 ± 0.14 logMAR after surgery (P = .006). Thirteen eyes (50%) lost at least one line of CDVA, 3 eyes (12%) lost two lines, and 4 eyes (15%) lost three lines. SE, cylinder, and apical keratometry decreased significantly. Corneal haze grade 1 was found in 15 eyes (57.7%), grade 2 in 6 eyes (23.1%), and grade 3 in 1 eye (3.8%). A significant correlation was seen between postoperative CDVA loss and corneal haze (P = .001) and history of atopy (P < .01), but not with corneal HOA change. CONCLUSIONS: Despite an improvement in UDVA and topographic values, the loss of CDVA, explained by postoperative haze, demonstrates that this procedure should be approached with caution, may not be as safe as initially thought, especially in patients with atopy and can cause severe visual acuity loss. [J Refract Surg. 2019;35(2):109-114.].

Accelerated corneal collagen crosslinking: Technique, efficacy, safety, and applications.

Corneal collagen crosslinking (CXL) is an approach used to increase the biomechanical stability of the stromal tissue. Over the past 10 years, it has been used to halt the progression of ectatic diseases. According to the photochemical law of reciprocity, the same photochemical effect is achieved with reduced illumination time and correspondingly increased irradiation intensity. Several new CXL devices offer high ultraviolet-A irradiation intensity with different time settings. The main purpose of this review was to discuss the current use of different protocols of accelerated CXL and compare the efficacy and safety of accelerated CXL with the efficacy and safety of the established conventional method. Accelerated CXL proved to be safe and effective in halting progression of corneal ectasia. Corneal shape responses varied considerably, as did the demarcation line at different irradiance settings; the shorter the exposure time, the more superficial the demarcation line. FINANCIAL DISCLOSURE: Dr. Santhiago is a consultant to Ziemer Ophthalmic Systems AG and Alcon Laboratories, Inc. None of the authors has a financial or proprietary interest in any material or method mentioned.

Predictability and Vector Analysis of Laser In Situ Keratomileusis for Residual Errors in Eyes Implanted With Different Multifocal Intraocular Lenses.

PURPOSE: To investigate potential differences in predictability, efficacy, and safety of corneal excimer laser to correct residual myopia, hyperopia, and astigmatism in eyes previously implanted with multifocal intraocular lenses using distinct optical surfaces and platforms for multifocality. METHODS: This prospective comparative study included 37 eyes submitted to laser in situ keratomileusis correction for residual errors after implantation of either an apodized diffractive-refractive (Restor) or a full-diffractive (Tecnis) multifocal intraocular lens. Data analysis included investigation of predictability, efficacy, and safety of excimer laser surgery to correct residual errors. A double-angle plot, using vector analysis, was also created to evaluate predictability of astigmatism correction. RESULTS: At 6-month follow-up, statistical analyses revealed a significant improvement when comparing preoperative (0.51 ± 0.25 and 0.44 ± 0.18) and postoperative values (0.17 ± 0.10 and 0.09 ± 0.07) of uncorrected distance visual acuity (P < 0.0001 and <0.0001), preoperative (0.92 ± 0.61 and 1.02 ± 0.45) and postoperative values (0.33 ± 0.23 and 0.19 ± 0.17) of manifest refractive spherical equivalent (P = 0.0006 and <0.0001), and preoperative (-1.08 ± 0.70 and -0.65 ± 0.42) and postoperative values (-0.25 ± 0.28 and -0.14 ± 0.21) of astigmatism (P < 0.0001 and <0.0001) in eyes implanted with Restor and Tecnis, respectively. Vector analysis revealed a predictable correction of astigmatism in all groups. Ninety-two percent of total eyes achieved a manifest refractive spherical equivalent within ±0.5 of emmetropia. CONCLUSIONS: Corneal excimer laser refractive surgery seems to be equally effective to correct different residual errors, including astigmatism, in eyes implanted with intraocular lenses with various platforms for multifocality.

Pachymetry-guided intrastromal air injection ("pachy-bubble") for deep anterior lamellar keratoplasty: results of the first 110 cases.

PURPOSE: To report intraoperative and 1-year postoperative results of the pachy-bubble technique for deep anterior lamellar keratoplasty (DALK). METHODS: This prospective interventional case series included 110 eyes of 107 patients with anterior corneal pathology who underwent DALK, including 78 with keratoconus. Outcome measures included the rate of bubble formation, rate of completing DALK, bubble types, complications, and visual and keratometric parameters. RESULTS: Intrastromal air injection was attempted in 109 eyes, and the air bubble was achieved in 93 eyes (85.3%). Intrastromal 2% methylcellulose injection was attempted in 9 eyes, after unsuccessful air bubble formation, and the viscobubble was achieved in 7 eyes (77.8%). Manual layer-by-layer dissection was performed in 8 eyes. Bubble formation was reached in 100 eyes (90.9%). Overall, 105 eyes (95.5%) achieved DALK. Air bubble occurred as type 1 (white margin) in 96.6% of the cases and as type 2 (clear margin) in 3.4%. There was a statistically significant improvement in all visual and keratometric parameters analyzed. Macroperforations converted to penetrating keratoplasty occurred in 5 eyes (4.5%) and microperforations in 12 (10.9%). There were significantly higher rates of perforation when a bubble was not achieved (P = 0.018) and when it was achieved as type 2 (P = 0.033). Interface haze occurred in 5 eyes (4.5%) and stromal rejection in 11 (10.0%). A short learning curve was observed for air bubble formation. CONCLUSIONS: Bubble formation, especially type 1, is the key to decrease the risk of perforation in DALK. The pachy-bubble was safe, effective, and reproducible in promoting DALK with air bubble and viscobubble formation with a short learning curve.

Topographic, corneal wavefront, and refractive outcomes 2 years after collagen crosslinking for progressive keratoconus.

PURPOSE: The aim was to report the corneal higher-order aberrations (HOA), the topographic metrics, and the visual and refractive outcomes 2 years after performing collagen crosslinking (CXL) for progressive keratoconus. The correlation among corneal HOAs, topographic metrics, and visual acuity changes was also investigated. METHODS: This is a prospective case series involving 42 eyes from 32 patients with progressive keratoconus treated with CXL. The main outcomes measured at baseline and 6, 12, and 24 months after treatment were uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), refractive changes, topographic data, and corneal aberrations. RESULTS: Two years after CXL treatment, the UDVA (P < 0.001), CDVA (P < 0.001), and spherical equivalent (P = 0.048) improved significantly. The corneal topographic data revealed significant decreases in apical keratometry (P < 0.001), differential keratometry (P = 0.031), and central keratometry (P = 0.003) compared with the baseline measurements. Aberration analyses revealed a significant reduction in coma (P = 0.016), trefoil (P = 0.018), secondary astigmatism (P < 0.001), quatrefoil (P = 0.031), secondary coma (P < 0.001), and secondary trefoil (P = 0.001). Corneal HOA (except quatrefoil) demonstrated a significant correlation with postoperative CDVA; the highest correlations were for coma (rho = 0.703, P < 0.001), secondary astigmatism (rho = 0.519, P = 0.001), and total HOA (rho = 0.487, P = 0.001). However, the corneal HOA changes were not statistically associated with improved visual acuity. After treatment, the reduction in apical keratometry was the only variable that correlated with the improvement in the CDVA (rho = 0.319, P = 0.042). CONCLUSIONS: After 2 years, CXL was found to be effective in improving the UDVA, CDVA, topographic metrics, and most corneal HOAs in eyes with progressive keratoconus. A significant reduction was observed in apical keratometry, and this reduction directly correlated with an improvement in visual acuity.

Corneal ectasia secondary to LASIK after arcuate keratotomy.

PURPOSE: To present a case of corneal ectasia after LASIK in a patient with previous arcuate keratotomy. METHODS: Case report. RESULTS: The patient underwent arcuate keratotomy in both eyes in 1997 for with-the-rule regular hyperopic astigmatism and uneventful bilateral LASIK for residual astigmatism 5 years later. Visual acuity and refraction remained stable for 5 years, when the patient noticed worsening visual acuity. Corneal topography showed progressive inferior steepening, confirming the diagnosis of ectasia. Corneal high-resolution optical coherence tomography revealed a normal LASIK flap. The patient had no risk factors for corneal ectasia other than previous incisional surgery. CONCLUSIONS: This case suggests that isolated arcuate keratotomy can be a significant risk factor for the development of corneal ectasia after LASIK.

Postoperative pain after corneal collagen cross-linking.

PURPOSE: To evaluate the postoperative pain after corneal collagen cross-linking (CXL). METHODS: : This prospective study included 178 consecutive eyes of 135 patients with progressive keratoconus who underwent CXL at Sadalla Amin Ghanem Eye Hospital, Joinville, Brazil. Pain was assessed postoperatively using the need for analgesia with 30 mg of codeine (Tylex) and by the patients' subjective evaluation on the Wong-Baker FACES Pain Rating Scale at the end of each day until postoperative day (PO) 5. Correlation of postoperative pain with maximum keratometric reading and central corneal thickness, which were assessed preoperatively, was investigated. RESULTS: Mean patient age was 23.38 ± 5.86 years. Mean (±SD) patient-scored pain decreased significantly (P < 0.05) from 2.78 (±1.68) on the day of surgery (immediate postoperative period, iPO) to 0.12 (±0.46) on PO5. The mean number of codeine pills was 0.94, 0.72, and 0.28 at iPO, PO1, and PO2, respectively, showing a significant decrease at each time point. Statistical analysis showed significant (P < 0.05) correlation between age and pain at PO3 and PO4 (the younger the patients the greater the pain) and between age and the number of codeine pills on iPO. There was no significant correlation between mean overall pain and preoperative apical keratometry (P = 0.546) and pachymetry (P = 0.072) readings. CONCLUSIONS: CXL postoperative pain can be intense, especially in the first 3 days, even with an aggressive pain control regimen; however, pain and the need for analgesia decreased significantly on each consecutive day. Pain was significantly correlated with the patient's age.

Bilateral progressive idiopathic annular lipid keratopathy.

Purpose. To report two unusual cases of idiopathic lipid keratopathy with symmetrical bilateral annular corneal lipid infiltration and describe confocal microscopy findings. Methods. Case reports. Results. We report two patients with bilateral peripheral deep stromal lipid deposits beginning in an arcuate pattern and progressing to a complete annular shape. Cholesterol crystals were observed in the paracentral area in both cases with characteristic crystalline-like structures in the confocal microscopy. Deep thin corneal blood vessels were observed in one patient, but no cause for then was established, despite decades of followup. This patient had an idiopathic limbitis as well, occurring in episodes. No previous ocular trauma, systemic disease or family history was reported for both cases. Conclusion. These two cases of idiopathic annular lipid keratopathy were observed for more than a decade with documented slow and insidious progression of the infiltrates, in spite of the use of topical steroids in one case. In the majority of other reported cases, a penetrating keratoplasty was made necessary. Differently, we showed that the visual acuity can remain quite good for years with very slow deterioration.

Corneal wavefront-guided photorefractive keratectomy with mitomycin-C for hyperopia after radial keratotomy: two-year follow-up.

PURPOSE: To assess corneal wavefront-guided photorefractive keratectomy (PRK) to correct hyperopia after radial keratotomy (RK). SETTING: Sadalla Amin Ghanem Eye Hospital, Joinville, Santa Catarina, Brazil. DESIGN: Case series. METHODS: Excimer laser corneal wavefront-guided PRK with intraoperative mitomycin-C (MMC) 0.02% was performed. Main outcome measures were uncorrected (UDVA) and corrected (CDVA) distance visual acuities, spherical equivalent (SE), corneal aberrations, and haze. RESULTS: The mean time between RK and PRK in the 61 eyes (39 patients) was 18.8 years ± 3.8 (SD). Before PRK, the mean SE was +4.17 ± 1.97 diopters (D); the mean astigmatism, -1.39 ± 1.04 D; and the mean CDVA, 0.161 ± 0.137 logMAR. At 24 months, the mean values were 0.14 ± 0.99 D (P<.001), -1.19 ± 1.02 D (P=.627), and 0.072 ± 0.094 logMAR (P<.001), respectively; the mean UDVA was 0.265 ± 0.196 (P<.001). The UDVA was 20/25 or better in 37.7% of eyes and 20/40 or better in 68.9%. The CDVA improved by 1 or more lines in 62.3% of eyes. Two eyes (3.3%) lost 2 or more lines, 1 due to corneal ectasia. Thirty eyes (49.2%) were within ± 0.50 D of intended SE and 45 (73.8%) were within ± 1.00 D. From 6 to 24 months, the mean SE regression was +0.39 D (P<.05). A significant decrease in coma, trefoil, and spherical aberration occurred. Three eyes developed peripheral haze more than grade 1. CONCLUSION: Corneal wavefront-guided PRK with MMC for hyperopia after RK significantly improved UDVA, CDVA, and higher-order corneal aberrations with a low incidence of visually significant corneal haze.

Peripheral sterile corneal ring infiltrate after riboflavin-UVA collagen cross-linking in keratoconus.

PURPOSE: To present 7 cases of peripheral sterile corneal infiltrates that occurred after corneal cross-linking (CXL) for progressive keratectasia. METHODS: Seven patients who had their progressive keratoconus documented underwent corneal deepithelization and subsequently CXL, which was performed with the application of 0.1% riboflavin with 20% dextran, and exposure to UVA light (370 nm, 2.9-3.1 mW/cm(2)) for 30 minutes. RESULTS: Nearly a week after the procedure, the patients presented with peripheral stromal infiltrates. The ring-like infiltrates were superficial and were present at the 9.0-mm zone. Sterile infiltration was diagnosed. Patients were treated with topical corticosteroids, and complete resolution was achieved after a few weeks of treatment. CONCLUSIONS: We hypothesize that the phototoxic effect on the corneal stroma may be the main mechanism that triggers these infiltrates. Alternatively, alterations in antigenicity that occur in native proteins after CXL could result in patients recognizing the proteins as nonself and mounting immune responses.

Pachymetry-guided intrastromal air injection ("pachy-bubble") for deep anterior lamellar keratoplasty.

To evaluate an innovative technique for intrastromal air injection to achieve deep anterior lamellar keratoplasty (DALK) with bare Descemet membrane (DM). Thirty-four eyes with anterior corneal pathology, including 27 with keratoconus, underwent DALK. After 400 µm trephination with a suction trephine, ultrasound pachymetry was performed 0.8 mm internally from the trephination groove in the 11 to 1 o'clock position. In this area, a 2-mm incision was created, parallel to the groove, with a micrometer diamond knife calibrated to 90% depth of the thinnest measurement. A cannula was inserted through the incision and 0.5 mL of air was injected to dissect the DM from the stroma. After peripheral paracentesis, anterior keratectomy was carried out to bare the DM. A 0.25-mm oversized graft was sutured in place. Overall, 94.1% of eyes achieved DALK. Bare DM was achieved in 30 eyes, and a pre-DM dissection was performed in 2 eyes. Air injection was successful in detaching the DM (achieving the big bubble) in 88.2% of the eyes. In keratoconus eyes, the rate was 88.9%. All cases but one required a single air injection to achieve DM detachment. Microperforations occurred in 5 cases: 3 during manual layer-by-layer dissection after air injection failed to detach the DM, 1 during removal of the residual stroma after big-bubble formation, and 1 during the diamond knife incision. Two cases (5.9%) were converted to penetrating keratoplasty because of macroperforations. The technique was reproducible, safe, and highly effective in promoting DALK with bare DM.

Semaphorin 7A promotes angiogenesis in an experimental corneal neovascularization model.

PURPOSE: To characterize the involvement of Semaphorin 7A (Sema7a) in corneal neovascularization (NV). METHODS: We generated anti-Sema7A antibodies to detect protein expression in corneal fibroblasts. Corneal fibroblast cells were cultured, stimulated with basic fibroblast growth factor (bFGF or FGF-2), immunostained with anti-Sema7A antibodies, and visualized by confocal microscopy. bFGF pellets were implanted in mouse corneal micropockets for 3-10 days, and corneal sections were immunostained with anti-Sema7A antibodies. Mouse corneas were injected with a Sema7A expression vector or a control vector for 3, 7, and 10 days. Mouse corneas were imaged by slit lamp microscopy, and areas of corneal NV were calculated using the ImageJ program. Mouse corneal sections were also immunostained with anti-macrophage marker (F4/80) and anti-vascular endothelial growth factor (VEGF)-A antibodies. RESULTS: Our data showed enhanced Sema7A expression levels in bFGF-stimulated cultured corneal fibroblasts. bFGF corneal implantation also demonstrated enhanced Sema7A expression. Corneas injected with a Sema7A expression vector showed evidence of significant corneal NV compared to controls on day 10 (1.8 mm(2) vs. 0.11 mm(2); p < 0.02). Additionally, immunolocalization of Sema7A expression vector-injected corneas (at day 7) revealed macrophage recruitment and enhanced VEGF-A levels. CONCLUSIONS: We demonstrated that Sema7A was expressed in vascularized corneas and showed pro-angiogenic properties in our corneal model. Understanding the mechanism of Sema7A in angiogenesis may provide a therapeutic target for the treatment of corneal angiogenesis-related disorders.

Visual performance of an apodized diffractive multifocal intraocular lens with +3.00-d addition: 1-year follow-up.

PURPOSE: To determine whether implantation of a multifocal intraocular lens (IOL) with a lower addition (+3.00 diopters [D]) at the lens plane results in better intermediate visual acuity 1 year after surgery compared with a multifocal IOL with higher addition (+4.00 D). METHODS: This prospective, randomized, double-masked study included 80 eyes from 40 patients. Twenty patients were implanted bilaterally with the ReSTOR +3.00-D add IOL and 20 patients were implanted bilaterally with the ReSTOR +4.00-D add IOL. Primary outcome measures were distance, intermediate, and near visual acuity. Secondary outcomes were defocus curves, best reading distance, mesopic and photopic contrast sensitivity, quality of life, and spectacle independence. Monocular and binocular visual acuity were measured as uncorrected and corrected distance visual acuity at 4 m, uncorrected near and distance-corrected near visual acuity at 40 cm, and uncorrected intermediate visual acuity and distance-corrected intermediate visual acuity at 50, 60, and 70 cm. RESULTS: Twelve months postoperatively, no statistically significant difference between groups in distance and near visual acuity was noted. The ReSTOR +3.00-D add group performed better than the ReSTOR +4.00-D add group at all intermediate distances studied. The ReSTOR +4.00-D group chose a reading distance 8 cm closer than the +3.00-D group. Both groups performed similarly with respect to contrast sensitivity, quality of life, and spectacle independence rates. CONCLUSIONS: Patients implanted with a multifocal IOL with lower addition (ReSTOR +3.00 D) had better performance at intermediate distances compared with the ReSTOR +4.00-D add IOL with similar performance for distance and near visual acuity, contrast sensitivity, and quality of life.

Collagen crosslinking with riboflavin and ultraviolet-A in eyes with pseudophakic bullous keratopathy.

PURPOSE: To evaluate the safety and efficacy of corneal collagen crosslinking (CXL) in patients with painful pseudophakic bullous keratopathy (PBK). SETTING: University of São Paulo, São Paulo and Sadalla Amin Ghanem Eye Hospital, Joinville, Santa Catarina, Brazil. METHODS: This prospective study included consecutive eyes with PBK that had CXL. After a 9.0 mm epithelial removal, riboflavin 0.1% with dextran 20% was applied for 30 minutes followed by ultraviolet-A irradiation (370 nm, 3 mW/cm(2)). Therapeutic contact lenses were placed for 1 week. Corneal transparency, central corneal thickness (CCT), and ocular pain were assessed preoperatively and 1 and 6 months postoperatively. Statistical analysis was by paired t tests. RESULTS: Fourteen patients (14 eyes) with a mean age 71.14 years +/- 11.70 (SD) (range 53 to 89 years) were enrolled. Corneal transparency was better in all eyes 1 month after surgery. At 6 months, corneal transparency was similar to preoperative levels (P = .218). The mean CCT was 747 mum preoperatively and 623 mum at 1 month; the decrease was statistically significant (P<.001). At 6 months, the mean CCT increased to 710 mum, still significantly thinner than preoperatively (P = .006). Pain scores at 6 months were not significantly different than preoperatively (P = .066). CONCLUSIONS: Corneal CXL significantly improved corneal transparency, corneal thickness, and ocular pain 1 month postoperatively. However, it did not seem to have a long-lasting effect in decreasing pain and maintaining corneal transparency in patients with PBK.

Customized topography-guided photorefractive keratectomy with the MEL-70 platform and mitomycin C to correct hyperopia after radial keratotomy.

PURPOSE: To evaluate topography-guided photorefractive keratectomy (PRK) for correcting hyperopia and astigmatism after radial keratotomy (RK). METHODS: Prospective study of 12 consecutive patients (19 eyes) who were treated with topography-guided PRK with 0.02% mitomycin C using an Asclepion-Meditec MEL-70 excimer laser with a 9.5-mm ablation zone. All eyes were operated by the same surgeon and followed for 1 year. RESULTS: Thirteen eyes had complete epithelialization by day 7 and all eyes by day 10. At 1 year, uncorrected visual acuity was 20/25 or better in 42.1% of eyes and 20/40 or better in 68.4%. Preoperative mean spherical equivalent refraction was +3.80+/-2.47 diopters (D) and +0.24+/-2.36 D (P<.001) 1 year postoperative, with 47.4% of eyes being within +/-1.00 D and 73.7% within +/-2.00 D. Preoperative mean cylinder was -2.30+/-1.41 D and -0.62+/-0.73 D (P<.001) 1 year postoperative. At 1 year, 68.4% of eyes gained at least 1 line of best-spectacle corrected visual acuity, 36.8% gained more than 1 line, and only 2 eyes lost 1 line (one due to corneal haze). Three eyes developed central haze. Mean regression from 6 to 12 months in these 3 eyes was +1.83 D and in the remaining 16 eyes was -0.50 D. CONCLUSIONS: Topography-guided PRK with mitomycin C was safe and reasonably effective for the treatment of hyperopia after RK.