Alfredo Vega-Estrada

Visual Outcomes of a Trifocal Aspheric Diffractive Intraocular Lens With Microincision Cataract Surgery

PURPOSE To evaluate the visual outcomes of patients with a new diffractive trifocal intraocular lens (IOL). METHODS A trifocal diffractive Fine Vision IOL (Physiol, Liege, Belgium) was implanted after microincision cataract surgery (MICS) in 40 eyes of 20 patients with bilateral cataract. The monocular and binocular visual performance and the refractive status were assessed, as well as the defocus curve and contrast sensitivity at 1 and 6 months postoperatively. RESULTS The monocular visual outcomes (logMAR) at 6 months postoperatively were uncorrected distance visual acuity 0.18 ± 0.13, uncorrected near visual acuity 0.26 ± 0.15, and uncorrected intermediate visual acuity 0.20 ± 0.11. With the best distance correction, the visual outcomes were 0.05 ± 0.06 for corrected distance visual acuity, 0.16 ± 0.13 for distance corrected near visual acuity, and 0.17 ± 0.09 for distance corrected intermediate visual acuity. Binocular defocus curve at 6 months shows a wide range of useful vision with 0.19 ± 0.08 (logMAR) at -1.50 diopter defocus. The monocular contrast sensitivity under scotopic conditions (3 cd/m(2)) was within normal range for a population older than 60 years. CONCLUSION The trifocal Fine Vision IOL can restore vision at different distances after cataract surgery, specifically intermediate and near vision.

Outcome Analysis of Intracorneal Ring Segments for the Treatment of Keratoconus Based on Visual, Refractive, and Aberrometric Impairment

PURPOSE To analyze the outcomes of intracorneal ring segment (ICRS) implantation for the treatment of keratoconus based on preoperative visual impairment. DESIGN Multicenter, retrospective, nonrandomized study. METHODS A total of 611 eyes of 361 keratoconic patients were evaluated. Subjects were classified according to their preoperative corrected distance visual acuity (CDVA) into 5 different groups: grade I, CDVA of 0.90 or better; grade II, CDVA equal to or better than 0.60 and worse than 0.90; grade III, CDVA equal to or better than 0.40 and worse than 0.60; grade IV, CDVA equal to or better than 0.20 and worse than 0.40; and grade plus, CDVA worse than 0.20. Success and failure indices were defined based on visual, refractive, corneal topographic, and aberrometric data and evaluated in each group 6 months after ICRS implantation. RESULTS Significant improvement after the procedure was observed regarding uncorrected distance visual acuity in all grades (P < .05). CDVA significantly decreased in grade I (P < .01) but significantly increased in all other grades (P < .05). A total of 37.9% of patients with preoperative CDVA 0.6 or better gained 1 or more lines of CDVA, whereas 82.8% of patients with preoperative CDVA 0.4 or worse gained 1 or more lines of CDVA (P < .01). Spherical equivalent and keratometry readings showed a significant reduction in all grades (P ≤ .02). Corneal higher-order aberrations did not change after the procedure (P ≥ .05). CONCLUSIONS Based on preoperative visual impairment, ICRS implantation provides significantly better results in patients with a severe form of the disease. A notable loss of CDVA lines can be expected in patients with a milder form of keratoconus.

Outcomes of a new microwave procedure followed by accelerated cross-linking for the treatment of keratoconus: a pilot study.

PURPOSE To analyze the initial data obtained in a group of patients treated with microwave keratoplasty followed by accelerated corneal collagen cross-linking (CXL) for the correction of keratoconus. METHODS Prospective, nonrandomized clinical study including six eyes from four patients treated with microwave thermal keratoplasty followed by accelerated CXL. Refractive, topographic, anterior aberrometry, and corneal biomechanics outcomes were analyzed during 6-month follow-up. RESULTS Immediately after the procedure, a significant reduction of >7.00 diopters (D) was observed in mean keratometry (P=.02). Uncorrected distance visual acuity increased from 0.92±0.52 logMAR (Snellen 20/160) preoperatively to 0.47±0.19 logMAR (Snellen 20/60) postoperatively (P=.05). No statistically significant change was found in corrected distance visual acuity (P=.28). Corneal higher order aberration decreased from 1.89±0.90 to 1.51±0.65 μm and corneal primary coma aberration decreased from 1.45±0.68 μm preoperatively to 0.84±0.23 μm postoperatively (P>.10). No statistically significant changes were found in the biomechanics variables (P=.40). A significant regression of the effect was assessed in keratometry at the end of follow-up (P=.03). CONCLUSIONS The Keraflex procedure may have the ability to improve refractive status in patients who suffer from keratoconus, as well as induce corneal remodeling to a more anterior regular surface. However, the current treatment regimen is not sufficient to maintain the flattening effect achieved and significant regression occurs.

Laser in situ keratomileusis for high hyperopia (>5.0 diopters) using optimized aspheric profiles: Efficacy and safety

Purpose To evaluate the clinical outcomes of laser in situ keratomileusis (LASIK) for high hyperopia using an excimer laser and optimized aspheric profiles. Setting Vissum Corporation and Miguel Hernández University, Alicante, Spain, and Research Institute of Ophthalmology, Giza, Egypt. Design Case series. Methods Eyes of patients with high hyperopia or hyperopic astigmatism (spherical equivalent [SE] ≥5.64 diopters [D]) had uneventful LASIK with an aspheric optimized ablation profile centered on the corneal vertex using an Amaris 500 kHz excimer laser and a femtosecond platform for flap creation with a temporal hinge. Results There was a significant improvement in uncorrected distance visual acuity 3 months postoperatively (P<.01), with no significant changes afterward (P=.72). At 6 months, the corrected distance visual acuity (CDVA) remained unchanged or improved in 90.48% of eyes; 2 eyes (9.52%) lost 2 lines of logMAR CDVA. The postoperative SE was within ±0.50 D of emmetropia in 70.37% of eyes. The LASIK enhancement rate at the end of the follow‐up was 29.4%. Significant induction of corneal primary spherical aberration and coma was found with 6.0 mm pupils (P<.01). The safety index was 0.94 and the efficacy index, 0.85. Conclusion Laser in situ keratomileusis for high hyperopia using optimized aspheric profiles requires further improvement in terms of safety but was still an effective and a predictable procedure. Financial Disclosure No author has a financial or proprietary interest in any material or method mentioned.

Clinical and Optical Intraocular Performance of Rotationally Asymmetric Multifocal IOL Plate-Haptic Design Versus C-Loop Haptic Design

PURPOSE To compare the visual and intraocular optical quality outcomes with different designs of the refractive rotationally asymmetric multifocal intraocular lens (MFIOL) (Lentis Mplus; Oculentis GmbH, Berlin, Germany) with or without capsular tension ring (CTR) implantation. METHODS One hundred thirty-five consecutive eyes of 78 patients with cataract (ages 36 to 82 years) were divided into three groups: 43 eyes implanted with the C-Loop haptic design without CTR (C-Loop haptic only group); 47 eyes implanted with the C-Loop haptic design with CTR (C-Loop haptic with CTR group); and 45 eyes implanted with the plate-haptic design (plate-haptic group). Visual acuity, contrast sensitivity, defocus curve, and ocular and intraocular optical quality were evaluated at 3 months postoperatively. RESULTS Significant differences in the postoperative sphere were found (P = .01), with a more myopic postoperative refraction for the C-Loop haptic only group. No significant differences were detected in photopic and scotopic contrast sensitivity among groups (P ⩾ .05). Significantly better visual acuities were present in the C-Loop haptic with CTR group for the defocus levels of -2.0, -1.5, -1.0, and -0.50 D (P ⩽.03). Statistically significant differences among groups were found in total intraocular root mean square (RMS), high-order intraocular RMS, and intraocular coma-like RMS aberrations (P ⩽.04), with lower values from the plate-haptic group. CONCLUSIONS The plate-haptic design and the C-Loop haptic design with CTR implantation both allow good visual rehabilitation. However, better refractive predictability and intraocular optical quality was obtained with the plate-haptic design without CTR implantation. The plate-haptic design seems to be a better design to support rotational asymmetric MFIOL optics.

Outcomes of intrastromal corneal ring segments for treatment of keratoconus: Five-year follow-up analysis

Purpose To report the long‐term refractive and optical quality outcomes of patients with intrastromal corneal ring segments (ICRS) to treat keratoconus and to analyze the results according to the patients’ age. Setting Vissum Instituto Oftalmologico de Alicante, Alicante, Spain. Design Case series. Methods The uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), manifest refraction, corneal topography, and aberrometry were evaluated before and after ICRS implantation in eyes with keratoconus. The follow‐up was 5 years in all cases. Results The study comprised 51 eyes (35 patients; age range 15 to 56 years). After 6 months, the improvement in the UDVA, CDVA, spherical equivalent, and mean keratometry (K) value was statistically significant (P<.05). Five years postoperatively, these parameters remained unchanged (P=.31). Slight regression (0.97 diopter [D]) was observed in the mean K between 6 months and 5 years; the regression was not statistically significant (P=.39). Anterior corneal aberrometric values decreased; however, the changes were not statistically significant (P≥.10). Linear regression analysis showed no correlation between the age of the patients and the changes observed in the mean K throughout the follow‐up (P > .05, r2 = 0.001). Conclusions Intrastromal corneal ring segment implantation in keratoconus patients provided long‐term improvement of the refractive and topographic status. There was no correlation between the amount of individual changes in the mean K reading and patient age. Financial Disclosure No author has a financial or proprietary interest in any material or method mentioned.

Clinical grading of post-LASIK ectasia related to visual limitation and predictive factors for vision loss

PURPOSE: To evaluate and characterize the main clinical features of post‐laser in situ keratomileusis (LASIK) ectasia, propose a grading system based on visual limitation, and identify predictive factors related to the degree of visual loss. SETTING: Vissum Corp., Alicante, Spain. DESIGN: Retrospective case series. METHODS: This study comprised consecutive eyes with corneal ectasia after LASIK from 1996 to 2010. Main outcomes were post‐LASIK ectasia corrected distance visual acuity (CDVA), CDVA loss, spherical equivalent (SE), and the corneal bulge (delta K). These outcomes were correlated with the residual stromal bed, ablation depth, ablation ratio (ablation depth:pachymetry), corneal depth (flap + ablation depth), and corneal ratio (corneal depth:pachymetry) to characterize their role in the severity of the disease. RESULTS: The mean post‐LASIK ectasia CDVA, CDVA loss, SE, and delta K were 0.20 logMAR ± 0.18 (SD), −0.13 ± 0.15 logMAR, −3.80 ± 3.86 diopters (D), and 4.77 ± 4.23 D, respectively. The ablation ratio had the strongest correlation with post‐LASIK ectasia CDVA (ρ = 0.477 and P<.001), whereas the corneal ratio had the strongest correlation with the post‐LASIK ectasia SE and delta K (ρ = −0.614 and ρ = 0.453, respectively: P<.001). The ablation ratio was the main predictive factor for post‐LASIK ectasia CDVA loss (relative risk, 2.04; P=.049). CONCLUSIONS: The grading system based on visual limitation was consistently represented by differences in CDVA loss, SE, and delta K. A high amount of tissue removed by the refractive procedure was associated with greater corneal biomechanical destabilization, increased corneal steepening, and a worse prognosis. Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned.

Laser-assisted in situ keratomileusis in high levels of myopia with the amaris excimer laser using optimized aspherical profiles.

PURPOSE To evaluate the clinical outcomes of laser-assisted in situ keratomileusis (LASIK) surgery for the correction of high myopia using a new generation of excimer laser (500-Hz repetition rate) and optimized aspherical profiles. DESIGN Retrospective interventional case series. METHODS Retrospective study including 51 eyes of 32 patients (age range 23-61 years) with high levels of myopia or myopic astigmatism (spherical equivalent ≥8.5 diopters [D]). All cases underwent uneventful LASIK surgery using the sixth-generation excimer laser Amaris from Schwind and a femtosecond platform for flap creation. Postoperative changes in visual acuity and refraction were recorded and analyzed during a 6-month follow-up. RESULTS A significant improvement of about 15 logMAR lines was observed in uncorrected distance visual acuity (UCDVA) at 3 months after surgery (P < .01), with no significant changes afterwards (P = .61). This improvement was consistent with a significant reduction of manifest refraction (P < .01). Best corrected distance visual acuity (BCDVA) remained unchanged or improved in 98% of eyes at 3 months postoperatively, with only 1 eye losing 1 logMAR line of BCDVA. A similar distribution of BCDVA data was observed at 6 months postoperatively. A total of 84.3% of eyes had a postoperative spherical equivalent within ±0.50 D of emmetropia. A limited but significant induction of primary spherical aberration and coma was also found (P < .01). LASIK enhancement was required during the follow-up in only 4 eyes (7.8%). CONCLUSIONS LASIK for high myopia using optimized aspherical profiles and the Amaris excimer laser is a safe, effective, and predictable procedure.

Geometrical Custom Modeling of Human Cornea In Vivo and Its Use for the Diagnosis of Corneal Ectasia

Aim To establish a new procedure for 3D geometric reconstruction of the human cornea to obtain a solid model that represents a personalized and in vivo morphology of both the anterior and posterior corneal surfaces. This model is later analyzed to obtain geometric variables enabling the characterization of the corneal geometry and establishing a new clinical diagnostic criterion in order to distinguish between healthy corneas and corneas with keratoconus. Method The method for the geometric reconstruction of the cornea consists of the following steps: capture and preprocessing of the spatial point clouds provided by the Sirius topographer that represent both anterior and posterior corneal surfaces, reconstruction of the corneal geometric surfaces and generation of the solid model. Later, geometric variables are extracted from the model obtained and statistically analyzed to detect deformations of the cornea. Results The variables that achieved the best results in the diagnosis of keratoconus were anterior corneal surface area (ROC area: 0.847, p<0.000, std. error: 0.038, 95% CI: 0.777 to 0.925), posterior corneal surface area (ROC area: 0.807, p<0.000, std. error: 0.042, 95% CI: 0,726 to 0,889), anterior apex deviation (ROC area: 0.735, p<0.000, std. error: 0.053, 95% CI: 0.630 to 0.840) and posterior apex deviation (ROC area: 0.891, p<0.000, std. error: 0.039, 95% CI: 0.8146 to 0.9672). Conclusion Geometric modeling enables accurate characterization of the human cornea. Also, from a clinical point of view, the procedure described has established a new approach for the study of eye-related diseases.

Internal, corneal, and refractive astigmatism as prognostic factors for intrastromal corneal ring segment implantation in mild to moderate keratoconus.

Purpose To improve the predictability of the visual and refractive outcomes of intrastromal corneal ring segment (ICRS) implantation in keratoconus patients and highlight the importance of internal astigmatism and its relationship to corneal and refractive astigmatism as prognostic factors. Setting Vissum Corporación, Alicante, and Centro de Oftalmología Barrquer, Barcelona, Spain. Design Retrospective case series. Methods Visual, refractive, topographic, and aberrometric variables were evaluated in eyes having ICRS implantation. The eyes were divided into 2 groups according to the relative position of the keratometric axis and refractive axis; that is, coincident axis (0 degree ± 15 [SD]) or uncoincident axis. Internal astigmatism was calculated by vectorial analysis. The relationship between topographic astigmatism and refractive astigmatism was evaluated. The follow‐up was 6 months. Results Of the 127 eyes evaluated, 79 had grade II keratoconus and 48 had grade I keratoconus. Statistically significant differences were found in the relative position of the refractive axis and keratometric axis (P=.017). Internal astigmatism had a significant correlation with the gain in visual acuity in patients with grade II keratoconus (r = −0.455, P=.0001). This relationship was less significant in patients with grade I keratoconus (r = −0.391, P=.021). Conclusion The predictability of visual and refractive outcomes can be significantly increased in grade II keratoconus patients when the relative position of the keratometric and refractive axes; the internal, corneal, and refractive astigmatism; and their combinations are used as prognostic factors. Financial Disclosure No author has a financial or proprietary interest in any material or method mentioned.