Sonia Yoo

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

PURPOSEnTo present the results after simultaneous photorefractive keratectomy (PRK) followed by corneal collagen cross-linking (CXL) for progressive keratoconus.nnnMETHODSnTwelve 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.nnnRESULTSnMean 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.nnnCONCLUSIONSnSimultaneous PRK followed by CXL seems to be a promising treatment capable of offering functional vision in patients with keratoconus.

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 patients visual outcome.

Intrastromal corneal ring segments for the treatment of irregular astigmatism

Intrastromal corneal ring (ICR; INTACS; Addition Technology, Inc., IL, USA) segments were first designed to provide a refractive adjustment by flattening the central corneal curvature while maintaining a prolate aspheric shape in the central optical zone. In contrast to excimer laser refractive techniques, ICR preserves corneal tissue and does not involve the central optical zone. Owing to these tissue-conserving properties, ICR has been proposed as an interesting surgical alternative in patients with corneal ectatic disorders. The treatment options for patients with corneal ectatic diseases and abnormal astigmatism depend on the severity of the disease. In patients with spectacle correction, ICR does not improve visual acuity and rigid contact lenses are not well tolerated; ICR seems to be an interesting, minimally invasive prekeratoplastic surgical technique. There are several publications in the literature supporting the safety and efficacy of this technique in patients with corneal ectatic diseases and abnormal astigmatism. ICR is considered to be a safe, reversible and minimally invasive procedure.