Blunt Scissors Stromal Dissection Technique Compared With Big-Bubble Deep Anterior Lamellar Keratoplasty.

OBJECTIVES: To evaluate the clinical findings and results of new modified manual deep anterior lamellar keratoplasty (M-DALK) technique compared with a big-bubble DALK (BB-DALK) technique in eyes with corneal scars or lesions. METHODS: A prospective, nonrandomized, comparative study included 65 eyes of 65 patients treated by M-DALK using the blunt scissors lamellar dissection technique or standard BB-DALK. Visual acuity, endothelial cell density, corneal cylinder (Cyl), central corneal thickness (CCT), residual stromal thickness and aberrometric values were recorded pre-treatment and 1, 3, 6, 12 and 18 months after treatment. RESULTS: Thirty-five eyes of 35 patients underwent deep anterior lamellar keratoplasty (DALK) with successful big-bubble technique, whereas 30 eyes of 30 patients underwent DALK with manual technique (in 10 eyes as a primary technique, in 20 eyes as a secondary technique). Successful big-bubble formation was achieved in 35 of 55 (64%) eyes. Microperforations occurred in three eyes in BB-DALK group, in six eyes in M-DALK group, and DALK could be completed successfully in these eyes. Visual acuity and endothelial cell loss results were not significantly different between groups during follow-up period. Mean CCT was significantly different between groups (P=0.035). Mean corneal Cyl, residual stromal thickness, and aberrometric values were similar between groups (P>0.05) at the final visit. CONCLUSION: New modified M-DALK technique has similar clinical findings and results with BB-DALK when using as a primary or secondary approach.

Conventional Corneal Collagen Cross-Linking Versus Transepithelial Diluted Alcohol and Iontophoresis-Assisted Corneal Cross-Linking in Progressive Keratoconus.

PURPOSE: To compare clinical outcomes of conventional corneal cross-linking (C-CXL) and diluted alcohol and iontophoresis-assisted corneal cross-linking (DAI-CXL) for the treatment of progressive keratoconus (KC). METHODS: Ninety-three eyes of 80 patients with KC were treated by C-CXL (n = 47) or DAI-CXL (n = 46). Visual acuity, keratometry, KC indexes, pachymetry, and aberrations were recorded before treatment and 1, 3, 6, and 12 months after treatment. The demarcation line was assessed 1 month after treatment. RESULTS: A significant improvement in visual acuity was observed at month 3 and month 6 after DAI-CXL and C-CXL, respectively. A significant decrease in maximum keratometry was observed in both groups at month 6. The front symmetry index significantly improved in both groups after 6 months, whereas the Baiocchi Calossi Versaci index significantly improved only after DAI-CXL at month 12 (P = 0.01). Average keratometry and other KC indexes were stable during 12 months of follow-up. Central corneal thickness decreased by 28.6 and 40.2 µm after DAI-CXL and C-CXL at month 1, respectively (P < 0.01), and it reached baseline at the 12th month (P = 0.14) only in the DAI-CXL group. Higher-order aberrations, coma, and spherical aberration significantly worsened at month 1 (P < 0.01) only after C-CXL; however, they improved significantly at month 12 compared with baseline (P < 0.05) in both groups. The demarcation line was visible in all cases at month 1 at a mean depth of 302 ± 56 µm and 311 ± 57 µm after DAI-CXL and C-CXL, respectively (P = 0.7). CONCLUSIONS: The DAI-CXL protocol seems as effective as the C-CXL protocol in halting KC progression after 1 year of follow-up.

Comparison of a new optical biometry with an optical low-coherence reflectometry for ocular biometry.

OBJECTIVE: To evaluate the repeatability and agreement of a new partial coherence interferometry optical biometer (AL-Scan, Nidek CO, Aichi, Japan) with optical low-coherence reflectometry device (Lenstar LS 900, Haag-Streit AG, Köniz, Switzerland). METHODS: Three consecutive measurements with the 2 devices were performed by the same examiner in 65 eyes of 65 patients with cataract. Patients were divided into 2 groups: axial length (AL) between 22 and 26mm (Group 1) and more than 26mm (Group 2). Comparisons were performed for AL, anterior chamber depth (ACD), keratometry (K, over 2.4mm diameter for AL-Scan and 2.3mm diameter for Lenstar) and corneal diameter (CD). Repeatability was analyzed using the intraclass correlation coefficient (ICC) and the agreement was by the Bland-Altman method. RESULTS: The repeatability of both devices was high for all biometry measurements (ICC over 0.970) in Group 1 and 2. The best repeatability was achieved for AL in each group. In both groups, the differences were statistically significant for all parameters (p<0.05) except for the measurement of AL and CCT (p>0.05). The Bland-Altman analysis showed good agreement between devices for all measurements in both groups. The closest agreement was for the AL measurements (ranged from -0.06 to 0.08mm in Group 1 and -0.05-0.07mm in Group 2). CONCLUSIONS: The new biometer provided excellent repeatability for all ocular biometry. In addition, there was good agreement between AL-Scan and Lenstar biometers for all parameters in cataractous patients with medium and long ALs.