Long-term results of combined transepithelial phototherapeutic keratectomy and corneal collagen crosslinking for keratoconus: Cretan protocol.

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.

Safety of high-intensity corneal collagen crosslinking.

PURPOSE: To evaluate the safety of a new high-intensity corneal collagen crosslinking (CXL) treatment protocol for keratoconus. SETTING: Vardinoyiannion Eye Institute of Crete, Faculty of Medicine, University of Crete, Heraklion, Crete, Greece. DESIGN: Prospective interventional case series. METHODS: Patients with progressive keratoconus had CXL using a new treatment protocol with 9 mW/cm(2) irradiance for duration of 10 minutes. The rate of reepithelialization, endothelial cell density (ECD), corrected distance visual acuity (CDVA), and steep and flat keratometry (K) values were evaluated preoperatively and 3 months postoperatively. RESULTS: Nine patients (10 eyes) were enrolled. No intraoperative or early postoperative complications were observed in any patient. The ECD did not change significantly 3 months postoperatively (P=.169). The CDVA improved from 0.19 logMAR ± 0.20 (SD) preoperatively to 0.10 ± 0.16 logMAR 3 months postoperatively; however, the improvement did not attain significance (P=.141). No eye lost lines of CDVA. The mean steep K readings decreased significantly from 48.04 ± 2.57 diopters (D) preoperatively to 46.51 ± 2.81 D 3 months postoperatively (P=.047); the mean flat K readings did not change significantly postoperatively (P=.285). CONCLUSIONS: Corneal collagen crosslinking at 9 mW/cm(2) irradiance for 10 minutes did not cause significant changes in ECD or intraoperative or early postoperative complications. None patient lost a line of CDVA 3 months after the procedure. FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned.

Long-term visual outcomes after Crystalens(®) HD intraocular lens implantation.

PURPOSE: Our purpose was to evaluate the long-term visual outcomes after bilateral implantation of Crystalens(®) HD (Bausch and Lomb, Inc.) accommodative intraocular lenses. METHODS: In this study, 25 patients (50 eyes) who underwent cataract surgery and bilateral Crystalens HD accommodative intraocular lens implantation were included. The Crystalens HD lens was implanted in the bag in both eyes, without any intra- or postoperative complications. The visual parameters measured before and after surgery were: uncorrected distance visual acuity, corrected distance visual acuity (CDVA) (using the Early Diabetic Retinopathy Study [EDTRS] logMAR charts), uncorrected intermediate visual acuity, and uncorrected near visual acuity using a Birkhäuser reading chart, at a distance of 66 cm and 33 cm for intermediate and near vision, respectively, directly illuminated by a lamp of 60 watts. After surgery, the patients were evaluated at 1, 3, 6, 12, 24, and 36 months. RESULTS: The mean age was 68.70±7.1 (range: 54 to 83) years. The mean follow-up was 42.72±0.49 (range: 42.33 to 43.27) months. The uncorrected distance visual acuity improved from 0.56±0.41 (range: 0 to 2) preoperatively to 0.19±0.13 (range: 0 to 0.38) (logMAR scale) at the last follow-up visit, and the CDVA improved from 0.17±0.18 (range: 0 to 0.7) preoperatively to 0.05±0.05 (range: -0.02 to 0.22) at the last follow-up visit. No eyes lost lines of CDVA during the follow-up period, while 54% of patients gained one or more lines of CDVA. The uncorrected intermediate and near visual acuity was J2 or better in 71% and 69% of our patients, respectively. CONCLUSION: Crystalens HD implantation seems to provide an improvement in visual acuity for far, intermediate, and near distances.

Topography-based keratoconus progression after corneal collagen crosslinking.

PURPOSE: The aim of this study was to report 2 cases with topographic keratoconus progression despite stability for a long-term period after corneal collagen crosslinking (CXL). METHODS: This is a case report. RESULTS: Two patients with progressive keratoconus underwent CXL treatment. Four and 5 years postoperatively, a topographic examination revealed an increase in the keratometric values indicating keratoconus progression. CONCLUSIONS: Post-CXL, topographic keratoconus progression may occur several years after, despite stability for a long-term period.

Anterior chamber angle evaluation with ultrasound biomicroscopy and optical coherence tomography in eyes implanted with a Crystalens.

This study employs optical coherence tomography (OCT) and ultrasound biomicroscopy (UBM) imaging as well as optical aberrometry to examine correlations between the anterior chamber angle aperture and visual acuity for near vision as well as coma along the horizontal and vertical axes in eyes implanted with an accommodative intraocular lens (Crystalens). A retrospective comparative consecutive case series of 22 eyes of 11 patients (5 males) uneventfully implanted with a Crystalens. Eyes with signs of posterior capsular opacification were excluded. All eyes were examined with 40 MHz UBM (Ellex Eyecubed) and spectral-domain OCT (Zeiss Visante). The angle aperture along the horizontal and vertical meridians was recorded based on the software of the systems. The coma root mean square (RMS) scores for the horizontal and vertical meridians were also recorded with the iTrace aberrometer. The anterior chamber angle was significantly wider along the horizontal axis compared with the vertical axis by UBM (46.37° and 44.20°, respectively) and by OCT (46.79° and 43.58°, respectively) (p = 0.02 in both cases, paired-samples t test). The correlations between the logMAR-converted Jaeger near vision score and the horizontal or vertical angle apertures was not statistically significant. Horizontal coma RMS was significantly inversely correlated with the horizontal angle aperture (r = -0.45, p = 0.03 and r = -0.39, p = 0.04 by OCT and UBM, respectively). Measurement of the horizontal angle aperture by the modalities used may represent an anatomical and clinical predictor of the optical aberrations induced by the Crystalens.

Topography-Based Keratoconus Regression.

PURPOSE: To report 3 cases of keratoconic patients who had progressive corneal topographic flattening during a 2-year follow-up period. METHODS: Case series. RESULTS: Three patients with bilateral keratoconus, each operated for advanced keratoconus in one of their eyes, were observed for possible progression of the disorder for a period of 2 years. During the 2-year follow-up period, topographic examination showed progressive corneal flattening in the nonoperated eye. Mean keratometry decreased in all patients, whereas topography showed significant flattening at the apex of the cone. Best-spectacle-corrected visual acuity increased in one of the patients, whereas the others had stable uncorrected and best-spectacle-corrected visual acuity during the follow-up period. All patients had positive family medical history for diabetes mellitus, but none of them was diabetic. CONCLUSIONS: This is the first report of topography-based keratoconus regression during a 2-year follow-up period.

Unilateral sulcus implantation of the crystalens HD.

PURPOSE: To evaluate the results after unilateral sulcus implantation of the Crystalens HD (Bausch & Lomb) accommodative intraocular lens (IOL). METHODS: This retrospective interventional case series comprised six eyes from three patients who underwent cataract surgery and bilateral Crystalens HD accommodative IOL implantation. The Crystalens HD was implanted in the bag in one eye (non-sulcus group) and, due to posterior capsule rupture, the lens was positioned in the ciliary sulcus in the fellow eye (sulcus group). RESULTS: Mean patient age was 66.3 ± 4.9 years (range: 60 to 72 years). Mean follow-up was 14.3 ± 3.2 months (range: 12 to 18 months) for the non-sulcus group and 14 ± 2 months (range: 12 to 16 months) for the sulcus group. Uncorrected distance visual acuity improved from 20/100 to 20/33 in the non-sulcus group and from 20/63 to 20/32 in the sulcus group during last follow-up. Corrected distance visual acuity improved from 20/35 to 20/20 in the non-sulcus group and from 20/27 to 20/23 in the sulcus group. Regarding near vision, all eyes in the sulcus group and 66.7% of eyes in the non-sulcus group achieved J1-J2 (Birkhauser reading chart). None of the eyes had any intra- (except posterior capsule rupture in the sulcus cases) or postoperative complications. CONCLUSIONS: Based on this small series, ciliary sulcus implantation of the Crystalens HD seems to be associated with no significant morbidity and provides satisfactory visual acuity outcomes.

Riboflavin's time-dependent degradation rate induced by ultraviolet A irradiation.

PURPOSE: To evaluate the time-dependent degradation rate of riboflavin after ultraviolet A (UVA) irradiation. METHODS: Two solutions of commercially available riboflavin solution (0.1%) were used; one served as control, while the second was irradiated using UVA light at 370 nm wavelength. Four samples of riboflavin solution were retrieved prior to irradiance and at 1, 5, 15, 30, and 60 minutes after irradiation (group A); at the same time points samples of riboflavin were retrieved from the control solution in order to assess environmental time-induced degradation of riboflavin (group B). All samples were immediately analyzed using liquid chromatograph mass spectrometry to detect riboflavin and its 2 subproducts, lumiflavin (LF) and lumichrome (LC). RESULTS: Mean percentage of riboflavin degradation was 0.0, 5.3, 9.1, 15.3, 20.6, and 33.3 at 0, 1, 5, 15, 30, and 60 minutes after UVA irradiation, respectively (group A). The time-dependent riboflavin degradation was statistically significant (p<0.05), while for group B there was no change in riboflavin concentration at all time intervals. In group A, mean LC concentration demonstrated a gradual concentration increase, reaching 2.386±1.526 ppm after 60 minutes of UVA exposure. CONCLUSIONS: The time-dependent degradation of riboflavin solution is significant, reaching 20.6% after 30 minutes of UVA exposure. It seems that only a small fraction of the overall riboflavin molecules break down since more than 65% remain intact even after 1 hour of UVA irradiation. Control riboflavin solution seems to be stable, as no degradation is evident even after 60 minutes.

Descemet stripping automated endothelial keratoplasty in a child after failed penetrating keratoplasty.

Use of Descemet stripping automated endothelial keratoplasty (DSAEK) has been reported in children for the treatment of postoperative endothelial decompensation and Descemet membrane break after forceps delivery. Rapid visual recovery and minimally induced postoperative astigmatism make DSAEK preferable to penetrating keratoplasty for the management of isolated endothelial disorders in this age group. We present a case of DSAEK in a 4-year-old boy for the management of irreversible endothelial rejection after penetrating keratoplasty. Three months after the procedure, the cornea remained clear with the donor button in place.

Combined corneal collagen cross-linking and posterior chamber toric implantable collamer lens implantation for keratoconus.

A 29-year-old woman with keratoconus underwent posterior chamber toric implantable Collamer lens (Visian ICL; STAAR Surgical, Monrovia, CA) implantation 12 months after corneal collagen cross-linking with riboflavin and ultraviolet radiation-A. No intraoperative or postoperative complications were observed. Three months postoperatively, uncorrected distance visual acuity improved from counting fingers to 20/40 and corrected distance visual acuity improved from 20/100 to 20/30. Combined cross-linking treatment and posterior chamber toric phakic Collamer lens implantation in a two-step procedure seems to be an effective method for correcting keratoconus in patients with high myopia and astigmatism. Despite the encouraging results, longer follow-up is necessary to evaluate the outcomes of this approach.

Management of post laser in situ keratomileusis ectasia with simultaneous topography guided photorefractive keratectomy and collagen cross-linking.

A thirty-nine year old man was referred to our institute due to progressive decreased visual acuity five years after bilateral Laser in situ Keratomileusis (LASIK). Topography revealed signs of post - LASIK ectasia. Patients' left eye was treated with simultaneous Topography Guided Photorefractive Keratectomy (PRK) followed by Corneal Collagen Cross Linking (CXL). Twelve months after the combined procedure both uncorrected distance visual acuity (UDVA) and corrected distance visual acuity (CDVA) showed significant improvement while topographic findings revealed an improvement of the astigmatic pattern. All higher order aberrations showed a significant decrease twelve months postoperatively. Combined topography guided PRK and corneal cross linking could represent an alternative treatment for post - LASIK ectasia.

Unintended epithelium-only flap creation using a femtosecond laser during LASIK.

PURPOSE: to present a patient in whom, during LASIK with the IntraLase femtosecond laser (Abbott Medical Optics), unintended epithelial (instead of anterior stromal) flaps were created in both eyes. METHODS: a 28-year-old man underwent bilateral LASIK using the IntraLase femtosecond laser programmed to create 100-microm flaps. Flap creation was performed uneventfully in both eyes but flap thickness was thinner than attempted. The flaps were easily torn during flap lift because they appeared to consist of epithelium only. Therefore, the procedure was immediately converted to photorefractive keratectomy with the use of mitomycin C. RESULTS: re-epithelialization occurred 3 days after the procedure in both eyes. Three months after treatment, uncorrected distance visual acuity was 20/25 in the right eye and 20/20 in the left eye with no signs of corneal haze on slit-lamp examination. CONCLUSIONS: despite the advantages of the IntraLase femtosecond laser in the creation of a LASIK flap, complications in terms of flap thickness may occur.

Transepithelial Phototherapeutic Keratectomy Using a 213-nm Solid-State Laser System Followed by Corneal Collagen Cross-Linking with Riboflavin and UVA Irradiation.

Purpose. To present a case of a keratoconic patient who underwent epithelial removal with transepithelial phototherapeutic keratectomy (t-PTK) using a 213-nm solid-state laser system followed by corneal collagen cross-linking (CXL) with riboflavin and ultraviolet-A (UVA) irradiation. Methods. Case report. Results. A twenty-four-year-old male with keratoconus underwent CXL treatment after epithelial removal with t-PTK using a solid-state laser system. No intra- or early postoperative complications were found. One month postoperatively, uncorrected visual acuity (UCVA) improved from 20/63 to 20/32 while best spectacle- corrected visual acuity (BSCVA) improved from 20/40 to 20/25. Corneal topography revealed a significant improvement which remained stable during the six-month followup period. Conclusions. Epithelial removal with t-PTK before CXL could improve patient's visual outcome.

Photorefractive keratectomy followed by same-day corneal collagen crosslinking after intrastromal corneal ring segment implantation for pellucid marginal degeneration.

A 28-year-old man with progressive pellucid marginal degeneration (PMD) had photorefractive keratectomy (PRK) followed by same-day corneal collagen crosslinking (CXL) for progressive PMD 12 months after intrastromal corneal ring segment implantation (Intacs). No intraoperative or early postoperative complications occurred. Nine months postoperatively, the uncorrected distance visual acuity improved from finger counting to 20/63 and the corrected distance visual acuity improved from 20/40 to 20/25. Corneal topography revealed a significant improvement in keratometry (from 46.73/38.67 to 44.92/39.01), which remained stable during the 9-month follow-up period. Despite the encouraging results, longer follow-up is necessary to evaluate the outcomes of this approach.

Interface Haze Formation After Ultra Thin Flap Laser in Situ Keratomileusis.

In this case series, five patients (10 eyes) underwent laser in siter keratomileusis (LASIK) for the correction of moderate myopia and astigmatism with the Schwind Carriazo Pendular microkeratome 90 mum head. Flap (superior hinged) thickness measured intraoperatively was assessed less than 70 mum in all eyes. On first month's postoperative examination, subepithelial mild corneal haze with consequent myopic regression was found in all patients. A significant improvement of haze formation and residual refractive error were observed during the following postoperative months. In conclusion, post-LASIK subepithelial corneal haze after thin flap creation is a temporarily potential complication that could affect patient's refractive error during the first postoperative month.

INTACS followed by KeraRing intrastromal corneal ring segment implantation for keratoconus.

PURPOSE: To describe the visual and refractive outcomes in three eyes (two keratoconic patients) with previous intrastromal corneal ring segments (INTACS, Addition Technology Inc) that underwent adjuvant single KeraRing (Mediphacos) intrastromal corneal ring segment implantation. METHODS: Two keratoconic patients (three eyes) with implanted INTACS segments underwent an additional (without explanting previous INTACS) single KeraRing segment implantation. RESULTS: No intraoperative complications occurred. Six months postoperatively, uncorrected distance visual acuity improved from 20/100 and 20/200 to 20/32 and 20/40 in the right and left eyes, respectively, of patient 1, and from 20/400 to 20/50 in the treated right eye of patient 2. Corrected distance visual acuity improved from 20/50 and 20/100 to 20/30 and 20/32 in the right and left eyes, respectively, of patient 1 and from 20/200 to 20/40 in patient 2. Keratometric measurements improved from 51.00/45.70 to 47.00/44.60 diopters (D) and from 50.80/48.80 to 42.70/40.30 D in the right and left eyes, respectively, of patient 1, and from 49.30/45.70 to 45.60/44.10 D in patient 2. CONCLUSIONS: In keratoconic patients with INTACS in place, adjuvant single intrastromal corneal ring segment (KeraRing) implantation could improve visual and refractive outcome.

LASIK flap buttonhole treated immediately by PRK with mitomycin C.

PURPOSE: To describe the visual outcomes of three patients who had LASIK flap buttonhole and were treated immediately with photorefractive keratectomy (PRK) and topical mitomycin C (MMC) 0.02%. METHODS: Three patients underwent bilateral LASIK with the SCHWIND Carriazo-Pendula 90 microm head microkeratome. In all three cases, a buttonhole flap occurred in the left eye. The flap was repositioned and phototherapeutic keratectomy for 50 microm was used for epithelial removal while immediate PRK with MMC was performed to treat the buttonhole flap. RESULTS: Three months after the procedure, uncorrected distance visual acuity and corrected distance visual acuity were 20/20 with regular topographic findings. CONCLUSIONS: Using PRK with MCC immediately after the occurrence of the LASIK flap buttonhole may be an effective treatment.

Intraoperative pachymetric measurements during corneal collagen cross-linking with riboflavin and ultraviolet A irradiation.

OBJECTIVE: To study central corneal pachymetric variations during corneal collagen cross-linking (CXL) treatment with the use of riboflavin and ultraviolet A irradiation (UVA). DESIGN: Prospective, noncomparative, interventional clinical study. PARTICIPANTS: Fifteen keratoconic patients (19 eyes) were enrolled. METHODS: All patients underwent riboflavin-UVA-induced corneal CXL. Intraoperative central corneal thickness (CCT) measurements using ultrasound pachymetry were performed during the procedure. Measurements were obtained after epithelial removal, after riboflavin drop instillation, and every 5 minutes (6 interval times) during UVA irradiation (30 minutes). MAIN OUTCOME MEASURES: Central corneal thickness measurements. RESULTS: Mean patient age was 26.9+/-6.5 years (range, 17-40 years). Ten were male and 5 were female. Mean preoperative CCT was 458.5+/-21.5 microm (range, 427-494 microm; 95% confidence interval [CI], 448-467 microm) and 415.7+/-20.6 microm (range, 400-468 microm; 95% CI, 406-426 microm) before and after epithelial removal, respectively. There was a statistically significant decrease (mean, 75 microm) of CCT between the epithelial removal interval (415.7+/-20.6 microm; range, 400-468 microm) and at the end of riboflavin solution instillation (340.7+/-22.9 microm; range, 292-386 microm; P<0.001). There was no statistically significant change in CCT during irradiation (P>0.05). There was no statistically significant difference between preoperative and 1-month postoperative endothelial cell count (preoperative, 2780+/-197 to 1-month postoperative, 2713+/-116; P = 0.14). No intraoperative, early postoperative, or late postoperative complications were observed in this patient series. CONCLUSIONS: During corneal CXL with the use of riboflavin and UVA irradiation, a statistically significant decrease of CCT was demonstrated.

Simultaneous topography-guided PRK followed by corneal collagen cross-linking for keratoconus.

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.

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.