Safety of EVO ICL Implantation With an Ophthalmic Viscosurgical Device-Free Technique in the Early 24 h After Surgery

Purpose: To compare the safety of the non-ophthalmic viscosurgical device (OVD) technique with that of the minimum OVD technique in EVO Implantable Collamer Lens (EVO-ICL) implantation.Methods: A total of 180 eyes of 90 consecutive patients were enrolled in the study, of which 100 eyes of 50 patients were treated with non-OVD technique, with a 55% success rate. The remaining 80 eyes of 40 patients were treated with min-OVD technique, so they were classified into the min-OVD group. Preoperative and postoperative intraocular pressure (IOP) measurements were collected and analyzed at 1, 2, 3, and 24 h. Visual acuity, corneal endothelial cell density (ECD), and corneal densitometry 24 h postoperatively were evaluated.Results: No significant difference was found in visual outcomes (P = 0.54) or ECD (P = 0.78) between the two groups. The operation time was significantly shorter in the non-OVD group (P < 0.0001). The IOP was significantly higher at 1 h (P < 0.0001), 2 h (P < 0.0001) and 3 h (P = 0.0045) postoperatively in the min-OVD group. The non-OVD group had significantly lower IOP than the min-OVD group at 1 h (P = 0.01) and 2 h (P = 0.013) postoperatively. The temporal corneal densitometry in the non-OVD group were significantly lower than those in the minimum group (P = 0.0063) 1 day after surgery.Conclusion: The non-OVD technique is safe and efficient for ICL implantation. It can be a safer method of ICL implantation in that it completely eliminates ophthalmic viscoelastic devices related complications without causing additional complications in short term.

Densitometric assessment of corneal transparency after correction of moderate myopia by femtosecond extraction of the lenticule through a small incision and using laser keratomilesis in situ with femtosecond assistance

Relevance. The study of the mechanisms of insufficiently rapid achievement of high visual acuity in the early postoperative period in the correction of myopia by the SMILE method is relevant. Purpose. To evaluate changes in corneal densitometry parameters after SMILE and FS-LASIK surgery in patients with moderate myopia. Material and methods. A study of 152 patients with moderate myopia was conducted, 68 were operated by SMILE and 84 – FS-LASIK. All procedures were performed using a VisuMax femtosecond laser and a MEL 80 excimer laser (Carl Zeiss Meditec, Germany). Assessment of visual acuity, corneal structure (OCT, Optovue, USA), corneal densitometry (Pentacam Scheimpflug, Germany) were performed before the operation, on the 1st, 5th day, 3, 6, 12 months after the operation. OCT scans were analyzed using the ImageJ program. Results. Оn the 1st day after SMILE, visual acuity (p=0.01) and transparency of the anterior and middle layers of the cornea were reduced than after FS-LASIK in the zone from 0 to 2 mm (p=0.045, p=0.001), from 2 to 6 mm (both p=0.001). These differences became statistically insignificant 5 days after surgery. By three and six months in the FS-ERASER group, the corneal transparency in the middle layers were reduced in the 0–2 mm and 2–6 mm zones (p=0.0001, p=0.001). In both groups, by 12 months, the corneal backscattering reached the values of the preoperative period (p>0,05). Conclusion. Refractive operations SMILE and FS-LASIK are accompanied by a decrease in corneal transparency, which is restored to preoperative values by 12 months. In the early postoperative period, an increase in densitometry indicators and a slower recovery of visual acuity after SMILE surgery may be due to active remodeling of the interface, which includes fragments of collagen fibrils and cellular components inside the intrastromal space. Key words: SMILE, FS-LASIK, densitometry, myopia

Corneal Densitometry Changes after Epithelium-Off Corneal Collagen Crosslinking

Background Keratoconus is a progressive non-inflammatory, degenerative disease that affects the integrity of the collagen matrix within the corneal stroma. Corneal cross-linking (CXL) has been described as the only modality in halting the disease progression over the past decade. Aim of the Work To compare the change in corneal densitometry before and 6 months after CXL using our unique protocol. Patients and Methods A prospective observational study was conducted on 30 eyes of 30 patients with progressive keratoconus. Epitheliumoff CXL was done with application of Riboflavin (VibeX RapidTM) for 6 minutes at a rate of 1 drop/ minute. UVA was delivered using the Avedro KXL machine (Avedro, Waltham, MA, USA) using the following parameters: 7.2 joules, 12 milli watt/ minute and 10 minutes of accelerated continuous UV delivery. Results Within the anterior (120 um) stromal layer, the concentric zones (0 to 2 mm) and (2 to 6 mm) showed a significant elevation of mean densitometry 6 months post-surgery (P = 0.020) and (P = 0.023) respectively compared to the baseline, However the concentric zones (6 to 10 mm) and (10 to 12 mm) showed a non-significant elevation of mean densitometry 6 months post-surgery (P = 0.167) and (P = 0.234) respectively compared to the baseline. Conclusion There is a significant increase in corneal densitometry 6 months postsurgery of the anterior stromal layer within the central 6 mm zone.

Anterior Segment Structures in Dark Iris Chinese Patients With Unilateral Fuchs’ Uveitis Syndrome

Purpose: To compare binocular anterior segment structures in Chinese patients with dark iris and unilateral Fuchs’ uveitis syndrome (FUS).Methods: This was a cross-sectional study including 34 phakic eyes (17 patients) with unilateral FUS. Anterior segment parameters were measured by rotating Scheimpflug imaging camera, noncontact specular microscopy and anterior segment optical coherence tomography.Results: Corneal volume was higher in FUS eyes compared to unaffected eyes (p<0.05). The iridocorneal angles were larger in FUS eyes compared to contralateral eyes (p<0.05). Mean endothelial cell density (ECD) was lower, and the coefficient of variation in endothelial cell size (CV) and average cell area of endothelial cells (ACA) were higher, in FUS eyes (p<0.05). Mean densitometry values of the midstromal cornea (zones with a diameter of 0-2, 2-6, or 10-12 mm), posterior (0-2, 2-6, 10-12, or 0-12 mm), or total thickness (0-2 or 2-6 mm) were higher in FUS eyes compared with unaffected eyes (p<0.05). ECD, CV, and ACA were negatively related to densitometry values of the midstromal and posterior cornea in the FUS eyes (p<0.05). Smoothness index of iris was lager in affected eyes (p<0.05).Conclusion: In Chinese patients with unilateral FUS, loss of endothelial cells, wider iridocorneal angle, thicker cornea, higher corneal densitometry of midstromal and posterior layer, and smoother iris were observed in affected eyes compared to contralateral eyes. These data can help to elucidate anterior segment characteristics of unilateral FUS in this population.

One-step viscoelastic agent technique for ICL V4c implantation for myopia

AIM: To investigate the safety and efficacy of using a one-step viscoelastic agent technique for posterior chamber phakic implantable collamer lens with a central hole (ICL V4c) implantation for myopia correction. METHODS: The one-step viscoelastic agent technique for ICL V4c implantation was used in 100 eyes of 52 patients. Refractive outcomes, intraocular pressure (IOP), corneal endothelial cell, and corneal densitometry values were evaluated at 1d, 1wk, 1 and 3mo postoperatively. RESULTS: All the surgeries were uneventful. No corrected distance visual acuity was lost after 3mo. IOP was 16.12±3.18 mm Hg before surgery, and 14.74±3.08 mm Hg at 1d and 14.50±2.56 mm Hg at 3mo after surgery (P<0.05). Corneal endothelial cell density was 2580±242 cell/mm², the coefficient of variation in cell size was 42.11%±7.92%, and the percentage of hexagonal cells was 40.98%±9.46% before surgery. No significant difference was found when these outcomes were compared between the studied time points (P>0.05). The corneal densitometry values of the central 2 mm and 2 to 6 mm areas showed similar regularities. After surgery, the values significantly increased at 1d, then decreased to the preoperative values at 1wk, and then continued to decrease at 3mo (P<0.05). CONCLUSION: The one-step viscoelastic agent technique for ICL V4c implantation is found to be safe and effective for myopia correction and causes little disturbance to the cornea.