PURPOSE: To report 18-month follow-up after transepithelial cross-linking (CXL) in young patients. METHODS: Thirteen eyes with keratoconus were evaluated (mean patient age: 14.4±3.7 years [range: 8 to 18 years]). Corrected distance visual acuity (CDVA); spherical equivalent refraction; keratometry (K); coma, spherical aberration, and higher order aberrations (HOAs) for a 5.0-mm pupil; and thinnest point were measured preoperatively and 1, 3, 6, 9, 12, and 18 months postoperatively by Scheimplflug camera. Endothelial cell density and anterior segment optical coherence tomography were also evaluated. Paired Student t test was used to compare preoperative and 12- and 18-month postoperative data. P <.05 was considered significant. RESULTS: Eighteen months after treatment, CDVA improved significantly, whereas K readings and HOAs showed statistically significant worsening ( P <.05). Spherical equivalent refraction, sphere and cylinder, coma, spherical aberration, thinnest point, and endothelial cell density did not show statistically significant changes ( P >.05). The mean demarcation line depth was 105 μm. No side effects were observed. CONCLUSIONS: Transepithelial CXL appears to be a safe treatment in children. Although improved CDVA was noted 18 months after treatment, this technique does not effectively halt keratoconus progression in children compared to standard CXL.

Purpose. Keratoconus (KC) is the most common indication for corneal transplantation in the Western world, with etiologic mechanisms still poorly understood. The disease prevalence in the general population is approximately 1:2000, and familial aggregation, together with increased familial risk, suggests important genetic influences on its pathogenesis. To date, several loci for familial keratoconus have been described, without the identification of any responsible gene in the respective mapped intervals. The aim of this study was to identify causative/susceptibility genes for keratoconus. methods. A total of 133 individuals (77 affected and 59 unaffected) of 25 families from southern Italy were genotyped using microsatellite markers and included in a genome-wide scan. Nonparametric and parametric analysis using an affected-only strategy were calculated by using genetic algorithm software. results. The chromosomal regions 5q32-q33, 5q21.2, 14q11.2, 15q2.32 exhibited the strongest evidence of linkage by nonparametric analysis (NPL = 3.22, 2.73, 2.62, and 2.32, respectively). The regions 5q32-q33 and 14q11.2 were also supported by multipoint parametric analysis, for which heterogeneity LOD (HLOD) scores of 2.45 (α = 0.54) and 2.09 (α = 0.46), respectively, were obtained under an affected-only dominant model. conclusions. This study represents the first KC linkage replication study on the chromosomal region 5q21.2 and reports evidence of suggestive linkage in several regions for which suggestive or significant linkage has been previously detected in different populations.

We describe a variant of the big-bubble technique in deep anterior lamellar keratoplasty (DALK) assisted by the IntraLase femtosecond laser, which we call IntraBubble. The use of the 60 kHz IntraLase femtosecond laser allows dissection of the pre-Descemet-plane lamella to a predefined corneal depth and creation of a channel in the posterior stroma 50 μm above the endothelium into which a smooth cannula for air injection can be introduced. We lengthened the channel created by the laser using a pointed dissector. Eleven consecutive patients with keratoconus were treated, and all procedures were completed as DALK. The big bubble was achieved in 8 eyes (73%). In 3 cases (27%), intraoperative microperforations occurred and the procedures were completed with hand dissection without complications. This new application of femtosecond laser technology could lead to standardization of the big-bubble technique in DALK.

To compare corneal aberration changes 1 year after myopic laser in situ keratomileusis (LASIK) performed with a mechanical microkeratome and IntraLase femtosecond laser. Twenty four eyes of 15 patients underwent LASIK with the Hansatome microkeratome, and 23 eyes of 13 patients underwent LASIK with the IntraLase femtosecond laser. A standard ablation was performed with the Bausch & Lomb Technolas 217 excimer laser. Topography data were used to calculate corneal aberrations with a 3.0 mm and 5.00 mm pupil, before and 12 months after surgery. The increasing factor (IF), defined as the ratio between the postoperative and preoperative mean value of the optical aberration, was calculated. The method of Mulhern et al was used to evaluate the centration of ablation. The comalike aberration was correlated with the decentration of ablation. The Student t test was used for the statistical anaylsis. The postoperative mean decentration of ablation was <0.5 mm. The comalike aberration appeared to be positively correlated with the decentration of ablation in both groups with a 5.0-mm pupil (P < 0.05). With a 3.00-mm pupil, the comalike aberration changed in the Hansatome group, whereas with a 5.00-mm pupil, all aberrations statistically significantly changed in both groups (P < 0.05). The IF similarly increased in 2 groups for spherical-like aberration, whereas IF greatly increased for total and comalike aberrations in the Hansatome group. Wavefront corneal aberrations change significantly 1 year after myopic LASIK performed with the Hansatome microkeratome as well as with IntraLase femtosecond lasers. Both of the procedures induce higher-order aberrations in the anterior corneal surface, but the amount of comalike aberration increases more with the Hansatome mechanical microkeratome.

To report the results 15 months after transepithelial corneal cross-linking by iontophoresis of riboflavin performed in pediatric patients affected by keratoconus. Fourteen eyes of 14 pediatric patients [mean age 13 ± 2.4 (SD) years; range, 10-18 years] were treated. Riboflavin solution was administered by iontophoresis for 5 minutes, and then UVA irradiation (10 mW/cm) was performed for 9 minutes. The corrected distance visual acuity measured as decimal number, spherical equivalent, refractive astigmatism, simulated K, corneal coma, spherical aberration, and high-order aberrations for 5.0-mm pupil and the thinnest point were measured preoperatively and 3, 6, 12, and 15 months postoperatively. The endothelial cell density was evaluated. The paired Student t test was used to compare data during the follow-up. Fifteen months after the procedure, the corrected distance visual acuity improved from 0.7 ± 1.7 to 0.8 ± 1.8 (P = 0.005). Spherical equivalent and refractive astigmatism as well as topographic and aberrometric data did not show significant changes. Also, the mean thinnest point and the endothelial cell density remained unchanged. The optical coherence tomography showed a nonhomogeneous but deep hyperreflective band with a fading effect extending through the anterior 180 μm of the cornea. No side effects were recorded. Transepithelial collagen cross-linking by iontophoresis, unlike other transepithelial techniques, seems to halt pediatric keratoconus progression over 15 months. However, we did not record significant improvement in higher-order aberrations and topographic indices.

Purpose: This review discusses the main aspects of pediatric keratoconus (KC) based on the current evidence to propose a guideline for helping early diagnosis and improving efficacy in treatment.Methods: This literature review was performed using PubMed, Ovid, and Elsevier databases. For the database search, the primary entered term included “pediatric keratoconus,” connected to descriptors such as “keratoconus,” “screening,” “corneal cross-linking” (CXL), and “keratoplasty.” Peer-reviewed and scholarly resources including original scientific articles and review articles were included.Results: The prevalence of KC changes among populations. The greatest incidence has been reported in Middle-Eastern populations, an estimate of incidence of 1/2,000 individuals per year. Scheimpflug imaging, optical coherence tomography, and slit-scan tomography are commonly used to detect early diagnosis. Epithelium-off CXL is the treatment that should be discussed as soon as there is evidence for disease progression. Actually, penetrating keratoplasty represents the more common technique of pediatric keratoplasty; however, deep anterior lamellar keratoplasty probably seems as the best surgical option because of healthy endothelium. Options to increase visual acuity thereafter include contact lens fitting and corneal implants.Conclusions: The review of the literature confirms that KC in children is more aggressive than that in adults. In the attempt to preserve a good visual acuity, guidelines for improving early diagnosis and appropriate treatment seem crucial.