Jesús Carballo-Álvarez

Soft contact lens fitting after intrastromal corneal ring segment implantation to treat keratoconus

PURPOSE To assess the feasibility of fitting a lathed soft toric contact lens (STCL) after the implant of intrastromal corneal ring segments (ICRSs) to treat keratoconus. METHODS Six months after ICRS implantation, 47 eyes of 47 patients (18-45 years) were fitted with a STCL. In each eye, we determined refractive error, uncorrected (UDVA) and corrected distance visual acuity (CDVA), and keratometry and asphericity measures. The outcome of STCL fitting was defined according to CDVA as successful (≤0.2logMAR) or unsuccessful (>0.2logMAR). Patients in the unsuccessful group were refitted with a piggy-back (PB) system. The above variables and the change in CDVA observed after STCL and PB lens fitting from spectacle CDVA were compared in the two groups. RESULTS STCL fitting was successful in 75%, 66.66% and 0% of the ICRS implanted eyes with stages I-III keratoconus, respectively. Spectacle-CDVA was 1.5 lines better and mean corneal power was 3.62D lower in the successful STCL group. In this group, the difference in cylinder axis between spectacles and STCL was 24.25° lower. PB refitting achieved a PB-CDVA ≤0.2logMAR in all cases. A similar difference in the CDVA change achieved by contact lenses versus spectacles was observed in the successful STCL and PB refitted groups. CONCLUSION STCL fitting is a feasible option in a large proportion of patients implanted with ICRS. When these lenses are unsatisfactory, a PB system is a good alternative.

Photopic and mesopic performance of 2 different trifocal diffractive intraocular lenses.

Purpose To assess photopic and mesopic vision in patients implanted with 2 different trifocal intraocular lenses (IOLs). Methods Fifty patients with cataract in both eyes had surgery with bilateral implantation of a trifocal FineVision (FV, n = 25) or AT LISA tri 839MP (LisaTri, n = 25) IOL. Three months after surgery, high-contrast photopic uncorrected distance visual acuity and corrected distance visual acuity (CDVA) were determined using the Early Treatment Diabetic Retinopathy Study test. Intermediate (65 cm) and near (40 cm) visual acuity were also measured, both with best distance correction (DCIVA and DCNVA, respectively). The CSV1000 test chart was used for binocular and monocular contrast sensitivity. Defocus curves were constructed under photopic and mesopic conditions. Results Mean patient age was 68.4 ± 5.5 years (FV) and 67.3 ± 5.6 years (LisaTri) (p = 0.540). No differences were found in terms of visual acuity between the groups. The CDVA, DCIVA, and DCNVA were 0.05 ± 0.06, 0.25 ± 0.10, and 0.13 ± 0.10 logMAR for FV and -0.04 ± 0.11, 0.32 ± 0.09, and 0.12 ± 0.11 logMAR for LisaTri, respectively (p = 0.09, p = 0.08, and p = 0.12). Photopic and mesopic defocus curves were comparable between the 2 IOL groups (p>0.05). Mesopic values were significantly worse than photopic in both groups for all the measured values (p<0.001). No differences in contrast sensitivity were observed between the 2 IOL groups (p>0.05). Conclusions Both trifocal diffractive IOLs provided good visual quality with a statistically significant decrease in mesopic conditions.

The effect of soft contact lens thickness in visual function after intracorneal ring segments surgery

OBJECTIVE To study the influence of soft contact lens (SCL) central thickness and material in keratoconus on visual function after intracorneal ring segment (ICRS) surgery. METHODS A pilot, experimental, prospective, cross-sectional and double-blind study was performed. Fourteen keratoconus patients with age range of 34.75±9.22years (7 males and 7 females) with ICRS implanted were involved in the study. Two different SCL materials [Hioxifilcon A (G-5X/p-GMA/HEMA) and Lucifilcon A (silicone-hydrogel)] with four different central thicknesses (0.1, 0.2, 0.3 and 0.4mm) were fitted in one eye per patient, selected randomly. High and low corrected distance visual acuity (CDVA) and contrast sensitivity (CS), corneal topography and corneal and total aberrometry were measured. RESULTS Corneal spherical like, coma like and root mean square (RMS) decreased significantly for 0.3 and 0.4mm in both SCL materials (p<0.05). Total RMS decreased significantly for 0.4mm with both SCL materials (p<0.05). High and low CDVA improved for 0.4mm of thickness for both materials (p<0.05). Statistically increasing were found in all thicknesses studied for CS in both materials (p<0.05). CONCLUSION A central thickness of the SCL equal or superior to 0.4mm seems to decrease the ocular high order aberration (HOA) and to improve the visual function in keratoconus patients implanted with ICRS. However, the modulus of rigidity of the SCL would not influence the HOA correction.

Changes in retinal nerve fiber layer thickness measurements in response to a trifocal intraocular lens implantation

AimsTo determine the changes produced on the peripapillary retinal nerve fiber layer (RNFL) thickness, measured by an spectral-domain optical coherence tomography (OCT), after the implantation of a trifocal diffractive intraocular lens (IOL) and compare them with the variations produced by a monofocal IOL implantation.MethodsA prospective, double masked study in which 50 eyes belonging to 50 patients with bilateral cataract were enrolled. Sequentially, the first 25 patients were bilaterally implanted with the trifocal diffractive IOL AT LISA® Tri 839 MP and the following 25 patients with the monofocal IOL CT ASPHINA® 409 M/MP. RNFL thickness measurements were performed by Cirrus HD®-OCT before and six months after the second eye surgery.ResultsMean patient age was 69.5 ± 6.1 years. In response to surgery, the average RNFL thickness increased 7.29 ± 10.51 µm at the AT LISA® Tri group and 1.96 ± 2.90 µm at the monofocal IOL group from the baseline (p = 0.017). Statistically significant differences in thickness variations were also detected in the superior sector (7.86 ± 7.70 µm at the AT LISA® Tri group vs 1.73 ± 5.74 µm at the monofocal group). Statistically significant differences between the pre and the postsurgery measurements were found in all sectors except the inferior one with the trifocal IOL and in two of the studied sectors (average and temporal) with the monofocal IOL.ConclusionsThe IOL implantation produce changes in the RNFL thickness, which are larger in case of a trifocal diffractive IOL.

Visual outcomes after progressive apodized diffractive intraocular lens implantation

Purpose: To assess photopic and mesopic vision in patients implanted with the Bi-Flex® M 677 MY bifocal intraocular lens (IOL). Methods: In this prospective clinical study, 25 patients with cataract in both eyes were subjected to cataract surgery and bilateral implantation of the Bi-Flex® M 677MY (Medicontur, Hungary) IOL. Three months after surgery, high-contrast photopic uncorrected distance visual acuity (UDVA) and corrected distance visual acuity (CDVA) were determined. Intermediate at 65 cm (DCIVA) and near at 40 cm (DCNVA) visual acuity were also measured, both with best distance correction. The CSV-1000 test chart was used to assess contrast sensitivity (CS). Defocus curves were constructed under photopic and mesopic conditions, determining binocular best-corrected visual acuity over the range +1.50 D to -4.00 D in 0.50-D steps. A KR-1W Wavefront Analyzer was used to measure pupil size and aberrometric outcomes. Presence and type of dysphotopsia were evaluated with the Likert scale. Results: Mesopic mean pupil diameter was 4.58 ± 0.73 mm. The mean values at 3 months were UDVA 0.03 ± 0.09, CDVA -0.05 ± 0.06, DCIVA 0.20 ± 0.07, and DCNVA 0.11 ± 0.08. Mean CS for the 4 frequencies examined were 1.66 ± 0.16, 1.75 ± 0.14, 1.39 ± 0.22, and 0.96 ± 0.19. Significant differences were observed in defocus curves for photopic and mesopic conditions. A significant correlation between pupil diameter and the dysphotopic photopic was found (r = 0.62; p = 0.02). Conclusions: The evaluated progressive apodized diffractive design IOL provides effective restoration of visual function in far and near vision distance with an adequate intermediate visual quality between -1.00 and -1.50 focus.

Forward light scatter and visual acuity before and after intrastromal corneal ring segment implantation at different stages of keratoconus

To assess forward light scatter (stray light) before and after intrastromal corneal ring segment (ICRS) implantation at different stages of keratoconus and to examine correlation between postoperative stray light and visual acuity (VA).