Iontophoretic Transepithelial Collagen Cross-Linking Versus Epithelium-Off Collagen Cross-Linking in Pediatric Patients: 3-Year Follow-Up.

PURPOSE: To compare 3-year iontophoretic transepithelial corneal cross-linking (I-ON CXL) outcomes with epithelium-off collagen cross-linking (epi-off CXL) in pediatric patients. METHODS: Forty eyes of 28 consecutive pediatric patients [mean age 14.3 ± 2.5 (SD) years; range, 9-18 years] with keratoconus were evaluated. Twenty eyes of 15 patients underwent I-ON and 20 eyes of 13 patients epi-off CXL. Mean corrected distance visual acuity, spherical equivalent, maximum keratometry (Kmax), posterior elevation of the thinnest point, and thickness of the thinnest point were evaluated. The Student t test was used to compare baseline and postoperative data. Keratoconus progression as a function of preoperative Kmax and cone location was evaluated. RESULTS: At 36 months, corrected distance visual acuity statistically improved (from 0.18 ± 0.1 to 0.10 ± 0.1 logarithm of the minimum angle of resolution) in epi-off CXL, whereas spherical equivalent and posterior elevation of the thinnest point did not significantly change. Mean Kmax increased from the baseline +0.8 diopters (D) in epi-off and +2.9D in I-ON. In both groups, the thinnest point decreased. Keratoconus progression, defined by an increase of Kmax reading of the anterior corneal surface of at least 1.00D, occurred in 25% of epi-off and 50% of I-ON CXL over the 3-year period. Kmax value in I-ON, and cone location in both groups, seemed to be factors influencing the disease progression. CONCLUSIONS: In pediatric patients, 3 years after treatment, epi-off CXL halted keratoconus progression in 75% of eyes, whereas I-ON CXL seemed to slow down keratoconus progression in 50% of eyes, mainly in those with highest Kmax and paracentral cone.

Four years of corneal keratoplasty in Italian paediatric patients: indications and clinical outcomes.

PURPOSE: The purpose was to evaluate indications and clinical outcomes in paediatric corneal keratoplasty. METHODS: Fifty-four eyes of 43 patients who underwent corneal keratoplasty from the 1st of January 2010 through the 31st of December 2013 at the Bambino Gesù Children's Hospital in Rome, Italy, were retrospectively evaluated. To assess the effect of age on graft failure rate, the recipient age was considered as a dichotomous variable (≤5 or >5 years) and a 2X2 table was developed, using the chi-square test for testing the statistical significance. Furthermore, two separate subgroup analyses were conducted on patients of ≤5 years and those of >5 years, to evaluate the effect of penetrating keratoplasty (PK) or deep anterior lamellar keratoplasty (DALK) on the graft failure rate. The level of statistical significance was set at p < 0.05 RESULTS: Mean recipient age was 8.9 ± 5.7 [SD] years. Mean follow-up time was 22.8 months. Main preoperative diagnoses were keratoconus (37 %) and congenital glaucoma (20 %). Patients ≤5 years showed a higher percentage of graft failure (p = 0.0008). PK and DALK did not show statistically significant differences regarding the graft failure in both subgroups (p = 0.15 for ≤5 years group and p = 0.27 for >5 years group, respectively). However, across groups DALK provided a lower rate of graft failure. CONCLUSIONS: Our findings suggest that children older than 5 years show a significantly better graft outcome and that DALK seems to offer greatest benefits in terms of failure risk in paediatric patients.

The Big-Bubble Full Femtosecond Laser-Assisted Technique in Deep Anterior Lamellar Keratoplasty.

PURPOSE: To describe the big-bubble full femtosecond laser-assisted (BBFF) technique, which could be helpful in standardizing the big-bubble technique in deep anterior lamellar keratoplasty (DALK). METHODS: Ten eyes of 10 consecutive patients affected by keratoconus underwent the BBFF technique using the 150-kHz IntraLase femtosecond laser (Intra-Lase FS Laser; Abbott Medical Optics, Inc., Santa Ana, CA). A 9-mm diameter metal mask with a single fissure 0.7 mm wide oriented at the 12-o'clock position was positioned into the cone, over the laser glass. The laser performed a ring lamellar cut (internal diameter = 3 mm; external diameter = 8 mm) 100 µm above the thinnest point, with the photodisruption effectively occurring only in the corneal stroma corresponding to the fissure to create a deep stromal channel; subsequently, an anterior side cut created an arcuate incision, from the corneal surface to the deep stromal channel on the mask's opening site. The mask was removed and the laser performed a full lamellar cut 200 µm above the thinnest point to create a lamella. After the removal of the lamella, the air needle was inserted into the stromal channel and air was injected to achieve a big bubble. RESULTS: The big bubble was achieved in 9 eyes (all type 1 bubbles) and all procedures were completed as DALK. CONCLUSIONS: Preliminary results suggest that the BBFF technique could help in standardizing the big-bubble technique in DALK, reducing the "learning curve" for surgeons who approach this technique and the risks of intraoperative complications.

Iontophoretic transepithelial corneal cross-linking to halt keratoconus in pediatric cases: 15-month follow-up.

PURPOSE: To report the results 15 months after transepithelial corneal cross-linking by iontophoresis of riboflavin performed in pediatric patients affected by keratoconus. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.