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We report on clinical results of corneal collagen cross-linking (CXL), analyzing intraoperative results, results in postrefractive surgery ectasia, results by iontophoresis, and results analyzed according to age of the patient.

To report refractive, topographic, tomographic, and aberrometric outcomes 12 months after corneal cross-linking (CXL) in eyes with progressive advanced keratoconus.Prospective, nonrandomized, single-center clinical study.Twenty-eight eyes undergoing CXL between April and June 2006.Riboflavin-ultraviolet A (UVA)-induced CXL included instillation of 0.1% riboflavin-20% dextrane solution 30 minutes before UVA irradiation and every 5 minutes for an additional 30 minutes during irradiation.Uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), sphere and cylinder refraction, topography, tomography, aberrometry, and endothelial cell count were evaluated at baseline and at 1, 3, 6, and 12 months follow-up.Mean baseline UCVA and BSCVA were 0.17+/-0.09 and 0.52+/-0.17, respectively; 12-month mean UCVA and BSCVA were 0.27+/-0.08 and 0.72+/-0.16, a statistically significant difference (P0.05). Mean spherical equivalent refraction showed a significant decrease of 0.41 diopters (D). Mean baseline simulated keratometry (SIM K) flattest and steepest meridians and SIM K average were 46.10, 50.37, and 48.08 D, respectively; at 12 months, 40.22, 44.21, and 42.01 D, respectively, were recorded, a difference that was significant for all 3 indices (P0.05). Mean average pupillary power (APP) changed significantly from 47.50 to 41.04 D at 12 months (P0.05) and apical keratometry (AK) from 58.94 to 55.18 D (P0.05). The treated eyes showed no deterioration of the Klyce indices at 6 months postoperatively, whereas the untreated (contralateral) eyes did show deterioration. For a 3-mm pupil, there was a significant reduction (P0.05) in whole eye (total), corneal, higher order, and astigmatic wavefront aberrations. A significant difference (P0.05) in total coma and total spherical aberration after CXL was also observed. Mean baseline pupil center pachymetry and total corneal volume decreased significantly (P0.05) to 470.09+/-29.01 microm and 57.17+/-3.21 mm(3) from baseline values of 490.68+/-30.69 microm and 59.37+/-4.36 mm(3), respectively. Endothelial cell counts did not changed significantly (P=0.13).Corneal cross-linking seems to be effective in improving UCVA and BSCVA in eyes with progressive keratoconus by significantly reducing corneal APP, AK, and corneal and total wavefront aberrations at 1 year postoperatively.

The hyaloid vascular system (HVS) is a transient network of capillaries that nourishes the embryonic lens and the primary vitreous of the developing eye. We used proteomic analysis and immunohistochemical staining to identify activin receptor-like kinase-1 (ALK1), a type I receptor for transforming growth factor-β1, during the HVS regression phase. In addition, we overexpressed ALK1 in corneas implanted with bFGF (basic fibroblast growth factor) pellets and observed that ALK1 overexpression resulted in inhibition of bFGF-induced corneal neovascularization in vivo. Our data suggest that ALK1 may play a role in HVS regression during ocular development.

• PURPOSE: To evaluate the impact of different definitions of primary open angle glaucoma (POAG) on assessment of the diagnostic validity of Heidelberg Retinal Tomography (HRT). • DESIGN: Retrospective, cross-sectional study. • METHODS: A search of medline (1992-2003) led to the retrieval of 181 papers containing definitions of POAG, including the eight visual field (VF)-based definitions used for this study. A sample of 193 normal subjects, 222 patients with suspected POAG, and 103 with POAG underwent HRT and the 24 II Humphrey VF examinations to assess the diagnostic validity of HRT. POAG was defined on the basis of Glaucoma Hemifield Test (GHT) "out of normal limits" associated with corrected pattern standard deviation (CPSD) > 2 dB and intraocular pressure (IOP)

Purpose: To assess intraobserver and interobserver reproducibility of the measurement of stereometric parameters of the optic disc by means of the Heidelberg Retina Tomograph I (HRT). Study design: Observational study, with interobserver variability. Participants: Fifty-five volunteers (healthy subjects and patients with glaucoma). Methods: HRT examination of the optic disc was repeated on 3 consecutive days on 1 eye of each of the 55 subjects. During each session, five single images were randomly acquired by two independent observers. One mean topography image (MTI), based on three single images, was then built at each session. For the intraobserver intraimage evaluation, the two observers traced their own contour line on one randomly chosen MTI. This procedure was repeated three times. For the intraobserver interimage and interobserver intra/interimage evaluations, the two observers traced their own contour line on the MTI of the first session, which was then automatically superimposed on the MTIs of the other two sessions. Main Outcome Measures: Reproducibility of the 12 stereometric parameters was calculated for each observer by means of the intraclass correlation coefficient (ICC). The expected range of variability between two independent evaluations was calculated by the scatter-plots of each test-retest difference versus their mean. The standard deviation of the mean test-retest score differences was used to describe the spread of score differences. Results: The ICC ranged between 0.79 and 0.99 for intraobserver intraimage and between 0.56 and 1 for intraobserver interimage evaluation. The ICC ranged between 0.54 and 0.99 for interobserver intraimage and between 0.65 and 0.97 for the interobserver interimage evaluation. ICC was almost perfect to perfect for planimetric measures (0.81 < ICC ≤ 1), substantial to almost perfect for volumetric and cup measures (0.61 < ICC ≤ 0.99), and moderate to almost perfect for retinal nerve fiber layer related measures (0.41 < ICC < 0.99). The expected variability was low (95% confidence interval

To report refractive, topographic, aberrometric, and tomographic outcomes 24 months after corneal cross-linking (CXL) in patients up to 18 years of age with progressive keratoconus.Prospective, interventional case series.Forty eyes underwent riboflavin-ultraviolet A-induced CXL. Uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), sphere and cylinder, topography, aberrometry, tomography, and endothelial cell counts were evaluated at baseline and at 1, 3, 6, 12, and 24 months.Mean logarithm of the minimum angle of resolution baseline UCVA and BSCVA were 0.79 ± 0.21 and 0.39 ± 0.10, respectively. Mean UCVA and BSCVA at 2 years were 0.58 ± 0.18 and 0.20 ± 0.09, respectively. The improvement in UCVA and BSCVA was significant throughout the postoperative follow-up (P.05). Mean spherical equivalent refraction showed a significant decrease of 1.57 diopters (D) at 24 months (P = .02). Mean baseline simulated keratometry was 46.32 D in the flattest meridian and 51.48 D in the steepest meridian; at 2 years, the values were 45.30 D (P = .04) and 50.21 D (P = .07), respectively. For a 3-mm pupil, there was a significant reduction (P.05) in whole eye (total), corneal, higher-order, and astigmatic wavefront aberrations at 24 months. A significant difference (P.05) in total coma and total spherical aberration 2 years after CXL also was observed. Mean baseline pupil center pachymetry decreased significantly (P = .04) at 6 months, but recovered by 12 months and remained stable thereafter through the 2-year follow-up. Endothelial cell counts did not change significantly (P = .32).CXL improved UCVA and BSCVA in the study patients, most likely by significantly reducing corneal asymmetry and corneal as well as total wavefront aberrations.

Objectives: To report intraoperative and 24-month refractive, topographic, tomographic, and aberrometric outcomes after corneal collagen cross-linking in progressive advanced keratoconus. Methods: Prospective, nonrandomized single-center clinical study involving 28 eyes. Main outcome measures included uncorrected and best spectaclecorrected visual acuities, sphere and cylinder refraction, topography, tomography, aberrometry, and endothelial cell count evaluated at baseline and follow-up at 1, 3, 6, 12, and 24 months after treatment. Topography was also recorded intraoperatively. Results: Two years after treatment, mean baseline uncorrected and best spectacle-corrected visual acuities improved significantly (P=.048 and.001, respectively) and mean spherical equivalent refraction decreased significantly (P=.03). Mean baseline flattest and steepest meridians on simulated keratometry, simulated keratometry average, mean average pupillary power, and apical keratometry all decreased significantly (P.03). Deterioration of the Klyce indices was observed in the untreated contralateral eyes but not in treated eyes. Total corneal wavefront aberrations Z0 (piston), Z2 (defocus), and Z7 (III coma) decreased significantly (P.046). Mean 12-month baseline pupil center pachymetry and total corneal volume decreased significantly (P=.045). Endothelial cell counts did not change significantly (P=.13). Conclusions: Two years postoperatively, corneal collagen cross-linking appears to be effective in improving uncorrected and best spectacle-corrected visual acuities in eyes with progressive keratoconus by significantly reducing corneal average pupillary power, apical keratometry, and total corneal wavefront aberrations. Arch Ophthalmol. 2009;127(10):1258-1265

Purpose: To report the outcomes of topography-guided photorefractive keratectomy (PRK) for the treatment of myopia with or without astigmatism using the customized aspheric transition zone (CATz) ablation algorithm. Methods: In this study, 335 eyes underwent PRK using the NIDEK Advanced Vision Excimer laser platform (NAVEX). Mean preoperative manifest refraction spherical equivalent was −4.42±3.46 diopters (D) (range: −14.50 to ±0.50 D). Mean preoperative sphere was −3.94±3.43 D (range: −13.00 to −1.00 D), and mean preoperative cylinder was −0.96±1.05 D (range: −5.50 to 0.00 D). Refractive outcomes out to 1 year postoperatively were analyzed. Results: At least 6 months postoperatively, all eyes maintained or gained lines of best spectacle-corrected visual acuity (BSCVA). There was a 51% increase in the eyes that read 20/16 or better uncorrected compared with preoperative BSCVA. At 1 year postoperative, 252/280 (90%) eyes had BSCVA 20/20 or better. Refractive outcomes within ±0.50 D were observed in 223/275 (81%) eyes at 3 months, 228/300 (76%) eyes at 6 months, and 187/280 (67%) eyes at 1 year. Conclusions: Topography-guided PRK using CATz for the treatment of low, moderate, and high myopia is safe, effective, and predictable. [ J Refract Surg . 2009;25: S89–S92.]

Purpose: To evaluate one-year results of riboflavin/ultraviolet A corneal collagen Cross-Linking (CL) in 28 eyes with progressive keratoconus. Methods: Refraction, visual acuity, pachymetry, corneal topography and wavefront analysis were evaluated preoperatively and at one year after CL. Results: At year one, topographic and subjective astigmatism decreased, respctively from 4.76D to 4.44D and from 3.03 to 2.91D. Wavefront analysis showed coma reduction form 0.90 to 0.76μm. UCVA increased from 0.15 to 0.25 and BSCVA from 0.45 to 0.65. Cone area, cone diameter , apical keratometry and curvature gradient remained stable. Conclusions: Collagen CL appears to be a safe procedure to stabilize keratoconus and to reduce aberrometric comatic component.

Purpose: To describe a new keratoplasty procedure using intraoperative topography to reduce postoperative astigmatism. Methods: One hundred sixty-five eyes of 150 consecutive patients were enrolled in this prospective study. The most common diagnosis was keratoconus (78.8%). As many as 5.5% had post‐laser in situ keratomileusis ectasia. Keratoplasty was performed with the Hanna Corneal Trephine System. A 24-bite running suture was placed, using a specially developed marker. Suture adjustment was performed with the aid of an intraoperative topographer (Keratron Scout; OPTIKON 2000, Rome, Italy). The aim of the adjustment was to obtain an astigmatism #2.0 D on the operating table. In case of .3.0 D of astigmatism at 1 month after surgery, suture adjustment was performed using the same intraoperative topographer. Results: At 12 months postoperatevely (suture in), data from 108 (64%) eyes were available. The mean refractive astigmatism was 3.53 D, and the mean topographical astigmatism was 4.7 D. At 18 months (suture out), data from 32 eyes (19.4%) were available, and at 24 months, data from 29 eyes (13.3%) were available. The mean refractive astigmatism was 3.39 D at 18 months and 3.47 D at 24 months. The mean topographic astigmatism was 2.30 D at 18 months and 1.76 D at 24 months. Mean best spectacle-corrected visual acuity (BSCVA) was 0.51 at 3 months, 0.63 at 12 months (suture in), 0.67 at 18 months (suture out), and 0.78 at 24 months postoperatively. Conclusions: The combination of intraoperative topography and a 24-bite single running suture resulted in a stable astigmatism throughout the follow-up period, even after suture removal. BSCVA reached a 20/40 level as early as 3 months postoperatively and continued to rise after suture removal. The stability of astigmatism and BSCVA shortened the postoperative visual rehabilitation time and provided a high quality of vision early in the postoperative period.

Purpose To evaluate the sensitivity and specificity of optic disk examinations performed using the Moorfields regression analysis (MRA) of the Heidelberg Retina Tomograph (HRT) in differentiating normal from glaucomatous eyes. Design Retrospective cross-sectional study. Methods Five hundred and nineteen patients were included in the study for a total of 193 normal eyes, 213 with suspected glaucoma (primary open-angle glaucoma [POAG]), and 113 with POAG. The intervention consisted of optic disk imaging by means of HRT I. A mean of three repeated images was analyzed using version 2.01 software. The optic disk was classified as “normal/outside normal limits” on the basis of the MRA. The visual field was examined using the DS 24 II program (Humphrey perimeter), with a glaucomatous visual field being defined on the basis of an abnormal Glaucoma Hemifield Test and a statistically significant corrected pattern standard deviation greater than 2 dB. The results obtained with MRA were compared with those obtained using the multivariate discriminant analysis (MDA) provided in the HRT I. The main outcome measures were sensitivity, specificity, and positive and negative predictive values of HRT examination. Results The sensitivity and specificity of the HRT-MRA examination were, respectively, 74% and 94% (83% and 75% with MDA) when the patients with suspected POAG were excluded from the analysis; the figures were 74% and 85%, and 41% and 94% (83% and 64%, and 60% and 75% with MDA) when the same patients were included as being normal or having POAG. Conclusions In a broad clinical setting including normal subjects, patients with suspected POAG, and POAG patients, the HRT-MRA showed a high degree of diagnostic accuracy. The MRA was less sensitive but more specific than MDA. Greater diagnostic ability may be added by HRT-MRA examinations than by HRT-MDA to standard POAG diagnostic studies.