Retinal detachment after phacoemulsification in refractive surgery clinics: a large series analysis with variable follow-up during 16 years.

PURPOSE: To determine the long-term incidence of pseudophakic retinal detachment (PRD) after phacoemulsification and the weight of the main risk factors in the appearance of such complication in a large sample. To implement a customized formula and a software calculation program able to quantify the risk of suffering PRD applicable to all lens extraction patients. METHODS: Retrospective cumulative risk analysis conducted on 178,515 eyes operated under similar conditions in a group of refractive surgery clinics (Clínica Baviera SL) located in a relatively limited geographical area (Spain). A survival analysis was performed and the data were modelled using the Weibull regression to determine the risk over a period of 16 years and to estimate the association of different risk factors: sex, age, axial length (AXL) of the eye, intraoperative posterior capsule rents (PCR), and YAG laser capsulotomies. The resulting estimates were translated into a predictive equation for hazard rates and survival probabilities. Later, an application was developed to make prediction available for the clinical community in order to estimate the potential risk of any hypothetical case before lens surgery. RESULTS: Globally, 1521 (0.85%) cases of PRD were diagnosed during the period. The risk for PRD was significantly greater in males (5.48 [2.94-10.2]; p < 0.001), in long eyes (1.24 [1.21-1.26]; p < 0.001), and also after posterior capsule rents (13.97 [11.61-16.82]; p < 0.001). Posterior capsule rupture increased the risk of PRD up to fourteen times. CONCLUSIONS: From weaker to stronger impact, age, axial length, sex, and intraoperative posterior capsule rent were significant risk factors for the appearance of PRD after lens extraction.

Efficacy, safety and visual outcomes of cataract surgeries performed during blindness prevention programs in different locations in Kenya.

PURPOSE: To determine the visual outcomes achieved in terms of efficacy and safety during high-volume cataract surgery programs in different locations in Kenya. METHODS: Eight hundred eighty-one eyes of 849 patients underwent extracapsular cataract extraction with intraocular lens implantation in a retrospective, observational, consecutive cohort study on patients who underwent cataract surgery in five programs that a Spanish non-governmental organization conducted between 2013 and 2019 for the prevention of blindness in different geographical areas of Kenya: Thika, Athi River, Kissi, Bagavathi, and Nakuru. The programs were carried out by Spanish and Kenyan surgeons working together. RESULTS: Mean age was 66.81 ± 14.47 years. Fifty-one percent of the operated eyes (447 eyes) were women. 94% of patients belonged to six ethnic groups. The mean uncorrected distance visual acuity (UDVA) before surgery was 1.98 ± 0.98 logMAR (20/2000), which changed to 0.82 ± 0.68 logMAR (20/150) 3 months after surgeries. The corrected distance visual acuity (CDVA) was 0.4 ± 0.53 logMAR (20/50) 3 months after surgery, 77.5% of the patients had good visual outcomes, and 6.3% had poor outcomes. Preoperative UDVAs were significantly different with respect to the different geographical areas (Kruskal-Wallis; p < 0.001). The most common intraoperative complication was posterior capsule rupture (incidence, 4.2%, 37 of 881), and the most serious complication was expulsive hemorrhage (incidence, 0.1%, 1 of 881). CONCLUSIONS: Cataract programs performed in a middle-income country with the proper technique and standardized protocols of action improved the visual outcome of the patients. Dissimilar baseline status was found in different areas regarding preoperative visual acuities. Training programs of local surgeons should be reinforced.

Cataract surgery in surgical camps: outcomes in a rural area of Cameroon.

AIM: To assess the complications and visual outcomes of cataract surgery during an outreach eye camp in Cameroon in which two foreign ophthalmologists operate alongside a local one. MATERIALS AND METHODS: This is a retrospective and comparative cohort study. The patients were consecutively assigned to three groups depending on the ophthalmologist who performed the cataract surgeries. All eyes underwent manual sutureless incision cataract surgery with posterior chamber intraocular lens (PCIOL) implantation under peribulbar anesthesia. Postoperative visits were scheduled for the first day, first week and second month after the procedures. Intra- and postoperative complications, best-corrected visual acuity and also refractive errors were assessed. RESULTS: A total of 263 eyes underwent cataract extraction with PCIOL implantation. The percentage of eyes in which two or more lines of corrected distance visual acuity decreased were 2.4%, 2.7% and 0% for groups A, B and C, respectively. The percentage of eyes with good visual outcome (uncorrected distance visual acuity UDVA > 20/60) were, respectively, 82.09%, 81.43% and 80.82% for the three groups. Similar results were found between the three groups regarding complications. Ocular hypertension, transient corneal edema and hyphema were the incidences registered at the first postoperative control performed 24 h after surgery. The most common complication observed 2 months after surgery was posterior capsular opacity (2.6%). CONCLUSION: High-volume cataract surgery in low- and middle-income countries may have good visual outcomes and a low rate of complications when the procedures are performed by either foreign or local ophthalmologists. SYNOPSIS: A program of high-volume cataract surgery carried out in a rural environment with few resources can give good visual outcomes in the hands of both foreign and local experienced ophthalmologists.

Diffractive trifocal pseudophakic intraocular lenses in high myopic eyes: 2-year assessment after implantation.

PURPOSE: To assess the visual outcomes and ocular safety when implanting diffractive trifocal intraocular lenses in a population of high myopic eyes. METHODS: This is a retrospective cumulative clinical study. Two hundred five myopic eyes consecutively operated in the hospitals of Clínica Baviera, Spain, were included. All eyes presented an axial length equal or greater than 26 mm and were treated and examined following the same methodology for at least 2 years. Refractive and visual outcomes and also intraoperative or postoperative complications were tabulated for later analysis. Furthermore, a subjective questionnaire was completed by all patients at the end of the follow-up period. RESULTS: The percentage of eyes that lost two or more lines of corrected distance visual acuity (CDVA) was 5.9%, 11.5% and 10.7% 3, 12 and 48 months after surgeries respectively. However, 33% of eyes gained two or more lines of CDVA 2 years after implantation. Excimer laser correction of residual refractive error was performed after implants in 29.75% of eyes. Uncorrected distance visual acuities (UDVAs) were significantly better 1 year (0.10 ± 0.3 logMAR) and 2 years after the surgeries (0.10 ± 0.14 logMAR) compared with those estimated 3 months postoperatively (0.14 ± 0.15 logMAR; Kruskal-Wallis; p < 0.001). Mean near and intermediate uncorrected visual acuities remained stable from the first to the last postoperative visit (Kruskal-Wallis; p > 0.05 for all comparisons). Of the eyes, 27.31% were diagnosed and treated with yttrium aluminum garnet (YAG) laser after being diagnosed as having posterior capsular opacification. Retinal detachment (RD) was diagnosed in six eyes (2.92%). CONCLUSIONS: Diffractive trifocal IOLs have good efficacy and predictability in high myopic eyes. Retinal concerns should lead the surgeons to explore other alternatives for refractive surgery in young patients without cataracts.

Implantable Collamer Lens for Myopia: Assessment 12 Years After Implantation.

PURPOSE: To evaluate the long-term refractive and visual stability and the risks related to the implantation of Implantable Collamer Lens (ICL; STAAR Surgical, Monrovia, CA) phakic intraocular lens (PIOL) for myopia. METHODS: This retrospective, consecutive, cumulative clinical study was performed in a group of 144 eyes implanted with ICL PIOL for myopia. Only the cases with clinical data available 12 years after the implantation were included in the series. Corrected distance visual acuity (CDVA), uncorrected distance visual acuity, spherical equivalent, refractive astigmatism, endothelial cell density, ICL vaulting, and postoperative complications were analyzed. RESULTS: Mean spherical equivalent refraction was -16.90±4.26 diopters (D) preoperatively and -1.77±1.93 D 12 years postoperatively. Mean CDVA at the first and last visit were 0.31±0.19 logMAR and 0.22±0.22 logMAR, respectively (Mann-Whitney U test, P<.001). Twelve years postoperatively, 8.9% of eyes had lost more than two lines of CDVA. The incidence of clinically relevant cataracts (13.88%) was significantly linked to the use of the V3 model ICL (chi-square test, P=.007). During the follow-up period, a significant reduction in PIOL vaulting was observed (Kruskal-Wallis test, P<.05), and the mean endothelial cell density decreased by 19.75%. CONCLUSIONS: The ICL PIOL provided good refractive outcomes and stability in the long term. The incidence of cataracts is low when the latest models of this PIOL are used.

Confocal microscopy evaluation of the corneal response following AcuFocus KAMRA inlay implantation.

PURPOSE: To describe the corneal appearance on confocal microscopy after AcuFocus KAMRA Inlay (AcuFocus, Inc., Irvine, CA) implantation and evaluate the visual acuity compared to the confocal microscopy data. METHODS: Twelve eyes of 12 patients implanted with one of three models of the AcuFocus KAMRA Inlay (ACI 7000, 7000T, and 7000PDT) were prospectively evaluated by confocal microscopy 6 months after implantation. Additionally, 4 eyes of 4 patients explanted during the follow-up period were evaluated. RESULTS: Among the eyes implanted, mean epithelial thickness was 54.6 ± 22 µm. The subbasal nerve plexus was detected in 10 patients. The corneal nerves per unit area were 2.73 ± 2.1 sprouts/mm(2). The branch pattern was found in 8 patients. The mean keratocyte density value was 540 ± 210 cells/mm(2). A low grade of keratocyte activation was found in all patients. Among the eyes explanted, the mean wound healing opacity was 1,092.75 ± 1,877.35 µm/pixel. CONCLUSIONS: The corneal tolerance to the KAMRA Inlay appeared to be good. The inlay modified the normal structure of the corneal layer, but it was not associated with severe complications of the eye. Keratocyte activation was the finding most associated with a negative visual outcome. Confocal microscopy can be useful to evaluate the long-term evolution of the corneal layer changes following KAMRA Inlay implantation.

Comparative outcomes of bimanual MICS and 2.2-mm coaxial phacoemulsification assisted by femtosecond technology.

PURPOSE: To compare the efficacy and safety outcomes of bimanual microincision cataract surgery (MICS) versus 2.2-mm coaxial phacoemulsification assisted by Femtosecond LenSx (Alcon-LenSx Inc., Aliso Viejo, CA). METHODS: This prospective, randomized, observational, comparative case series comprised 50 cataractous eyes of 50 patients receiving femtosecond laser refractive lens surgery followed by a bimanual MICS technique with two 1-mm incisions (25 patients) (FemtoMICS group) and a coaxial phacoemulsification technique with a 1-mm paracentesis and a 2.2-mm principal incision (25 patients) (FemtoCoaxial group). The main outcomes measures were: ultrasound power, effective phacoemulsification time, postoperative spherical equivalent, higher-order aberrations (corneal and internal), corneal thickness, endothelial cell count, macular thickness, and complications during and after surgery. Both groups were absolutely comparable for all variables preoperatively. RESULTS: Mean ultrasound power was 1.8% ± 0.9% for MICS and 14.7% ± 4.9% for 2.2-mm incisions (P < .001). Effective phacoemulsification time values for MICS and 2.2-mm incisions were 1.5 ± 0.9 and 4.5 ± 2.9 sec, respectively (P = .002). Mean postoperative spherical equivalent was −0.26 for FemtoMICS and −0.33 for FemtoCoaxial (P > .05). The efficacy index at 1 month postoperatively was 160.2% for FemtoMICS and 149% for FemtoCoaxial. No significant differences were found in corneal thickness, endothelial cell count, and macular thickness. Complications included posterior capsule rupture (4%) and anterior capsule rupture with no posterior capsule tear (4%) for FemtoMICS and bridges due to incomplete capsulorhexis (4%) for FemtoCoaxial. CONCLUSIONS: MICS and coaxial phacoemulsification techniques assisted by the Femtosecond LenSx achieved excellent safety and efficient outcomes. The FemtoMICS technique was surgically and statistically more efficient than the FemtoCoaxial technique.

Effect of platelet-rich plasma in nerve regeneration after LASIK.

PURPOSE: To investigate the effect of topical eye application of platelet-rich plasma (E-PRP) on the recovery of corneal sensitivity after LASIK and the anatomical recovery of the sub-basal corneal plexus as studied by confocal microscopy. METHODS: This was a randomized, consecutive, controlled, prospective and masked study on 108 myopic eyes receiving LASIK. The main variables of the study were the increase in corneal sensitivity (Cochet-Bonet aesthesiometer; Luneau, Paris, France) and the aspect of the sub-basal nerve plexus (confocal microscope). Additionally, a biomicroscopic study of the epithelial status of the cornea and a subjective questionnaire were completed. Each eye of each patient was assigned to one of two groups: 54 eyes treated with balanced saline solution and 54 fellow eyes receiving PRP drops for 3 months. RESULTS: No significant differences were detected when the corneal sensitivity thresholds were compared at any postoperative visit in both groups (P > .05 for all comparisons). Almost identical sub-basal fiber densities were estimated for both groups before LASIK (t test, P = .66). However, the type and severity of staining detected during the slit-lamp examinations at the first and third month postoperatively were significantly less evident in the E-PRP treatment group (Wilcoxon test, P < .05). CONCLUSIONS: PRP drops have beneficial effects for promoting epithelial status after LASIK but have no positive effect on recovery of corneal sensitivity, probably due to the limited bioavailability of growth factors in corneal stroma when the substance is topically administered.

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.

Femtosecond laser cataract incision morphology and corneal higher-order aberration analysis.

PURPOSE: Analysis of the femtosecond laser refractive lens surgery corneal incision configuration and corneal higher-order aberration (HOA) effect from the first postoperative day. METHODS: High-resolution anterior segment optical coherence tomography was used to assess 20 eyes undergoing femtosecond laser refractive lens surgery with 2.2-mm minimal incision. The primary incision (tri-planar) actual length, cord length, surface angle, surface irregularity, and regional pachymetry values and the secondary incision (uni-planar) length, angle, surface irregularity, and pachymetry values were analyzed. Hartmann-Shack aberrometer was used to assess corneal HOAs to correlate the effect. Assessment was done preoperatively and 1 month postoperatively. RESULTS: The actual length, cord length, and surface angle means for the primary incision in the first postoperative day and month were 1.50 ± 0.1 and 1.47 ± 0.2 mm (P = .5), 1.41 ± 0.1 and 1.42 ± 0.2 mm (P = .8), and 27° ± 4° and 23° ± 5° (P = .07), respectively. The length and surface angle for the secondary incision in the first postoperative day and month were 1.17 ± 0.01 and 1.04 ± 0.1 mm (P = .05) and 52° ± 3° and 42° ± 5° (P = .007). The regional pachymetry values for the primary and secondary incisions were significantly increased in the first postoperative day and then significantly decreased after 1 month. All irregularities occurred in the posterior surface (endothelium): 2 cases of posterior gap (first day) and 1 case of posterior retraction (first month). The HOAs had not significantly changed preoperatively and after 1 month. CONCLUSIONS: The femtosecond laser refractive lens surgery incision is stable and does not significantly change the HOA.

Comparative analysis of the relationship between anterior and posterior corneal shape analyzed by Scheimpflug photography in normal and keratoconus eyes.

BACKGROUND: To analyze and compare the relationship between anterior and posterior corneal shape evaluated by a tomographic system combining the Scheimpflug photography and Placido-disc in keratoconus and normal healthy eyes, as well as to evaluate its potential diagnostic value. METHODS: Comparative case series including a sample of 161 eyes of 161 subjects with ages ranging from 7 to 66 years and divided into two groups: normal group including 100 healthy eyes of 100 subjects, and keratoconus group including 61 keratoconus eyes of 61 patients. All eyes received a comprehensive ophthalmologic examination including an anterior segment analysis with the Sirius system (CSO). Antero-posterior ratios for corneal curvature (k ratio) and shape factor (p ratio) were calculated. Logistic regression analysis was used to evaluate if some antero-posterior ratios combined with other clinical parameters were predictors of the presence of keratoconus. RESULTS: No statistically significant differences between groups were found in the antero-posterior k ratios for 3-, 5- and 7-mm diameter corneal areas (p ≥ 0.09). The antero-posterior p ratio for 4.5- and 8-mm diameter corneal areas was significantly higher in the normal group than in the keratoconus group (p<0.01). The k ratio for 3, 5, and 7 mm was significantly higher in the keratoconus grade IV subgroup than in the normal group (p<0.01). Furthermore, significant differences were found in the p ratio between the normal group and the keratoconus grade II subgroup (p ≤ 0.01). Finally, the logistic regression analysis identified as significant independent predictors of the presence of keratoconus (p<0.01) the 8-mm anterior shape factor, the anterior chamber depth, and the minimal corneal thickness. CONCLUSIONS: The antero-posterior k and p ratios are parameters with poor prediction ability for keratoconus, in spite of the trend to the presence of more prolate posterior corneal surfaces compared to the anterior in keratoconus eyes.

Efficacy and safety of mass cataract surgery campaign in a developing country.

PURPOSE: To determine the visual outcomes achieved in terms of efficacy and safety during a mass eye surgery campaign in a low-income developing country. METHODS: Three hundred fifteen eyes of 305 patients underwent extracapsular cataract extraction with intraocular lens implantation in a prospective, analytical, experimental, and nonrandomized study on patients who underwent cataract surgery during the campaign that two Spanish nongovernmental organizations conducted in December 2008 in a district hospital in Bobo-Dioulasso (Burkina Faso). RESULTS: Mean age was 61.97 ± 14.39 years. The mean uncorrected distance visual acuity before surgery was 2.17 ± 0.7 (20/3000), which improved to 0.86 ± 0.64 logMAR (20/150) 3 months after cataract surgery. The mean spherical equivalent at 3 months was -0.87 ± 1.90 diopters. The corrected distance visual acuity was 0.52 ± 0.44 logMAR (20/60) 3 months after surgery, 68.7% of the patients had good visual outcomes, and 9.16% had poor outcomes. A total of 41.4% of the operated eyes showed a spherical equivalent within ± 1.00 diopter of emmetropia. The most common intraoperative complication was posterior capsule rupture (incidence, 2.9%, 9 of 315), and the most serious complication was expulsive hemorrhage (incidence, 0.3%, 1 of 315). Three months after surgery, 2.9% (9 of 315) of the eyes was affected by posterior capsular opacity. CONCLUSIONS: A mass cataract campaign performed in a developing country with the proper technique and standardized protocols of action improved the visual outcome of the patients. The rate of incidence of extracapsular extractions is comparable to that estimated for developed countries.

Comparison of a new refractive multifocal intraocular lens with an inferior segmental near add and a diffractive multifocal intraocular lens.

PURPOSE: To compare the visual acuity outcomes and ocular optical performance of eyes implanted with a multifocal refractive intraocular lens (IOL) with an inferior segmental near add or a diffractive multifocal IOL. DESIGN: Prospective, comparative, nonrandomized, consecutive case series. PARTICIPANTS: Eighty-three consecutive eyes of 45 patients (age range, 36-82 years) with cataract were divided into 2 groups: group A, 45 eyes implanted with Lentis Mplus LS-312 (Oculentis GmbH, Berlin, Germany); group B, 38 eyes implanted with diffractive IOL Acri.Lisa 366D (Zeiss, Oberkochen, Germany). METHODS: All patients underwent phacoemulsification followed by IOL implantation in the capsular bag. Distance corrected, intermediate, and near with the distance correction visual acuity outcomes and contrast sensitivity, intraocular aberrations, and defocus curve were evaluated postoperatively during a 3-month follow-up. MAIN OUTCOME MEASURES: Uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), uncorrected near visual acuity (UNVA), corrected distance near and intermediate visual acuity (CDNVA), contrast sensitivity, intraocular aberrations, and defocus curve. RESULTS: A significant improvement in UDVA, CDVA, and UNVA was observed in both groups after surgery (P ≤ 0.04). Significantly better values of UNVA (P<0.01) and CDNVA (P<0.04) were found in group B. In the defocus curve, significantly better visual acuities were present in eyes in group A for intermediate vision levels of defocus (P ≤ 0.04). Significantly higher amounts of postoperative intraocular primary coma and spherical aberrations were found in group A (P<0.01). In addition, significantly better values were observed in photopic contrast sensitivity for high spatial frequencies in group A (P ≤ 0.04). CONCLUSIONS: The Lentis Mplus LS-312 and Acri.Lisa 366D IOLs are able to successfully restore visual function after cataract surgery. The Lentis Mplus LS-312 provided better intermediate vision and contrast sensitivity outcomes than the Acri.Lisa 366D. However, the Acri.Lisa design provided better distance and near visual outcomes and intraocular optical performance parameters.

Combining zonal refractive and diffractive aspheric multifocal intraocular lenses.

PURPOSE: To assess visual performance with the combination of a zonal refractive aspheric multifocal intraocular lens (MIOL) (Lentis Mplus, Oculentis GmbH) and a diffractive aspheric MIOL (Acri.Lisa 366, Acri.Tech GmbH). METHODS: This prospective interventional cohort study comprised 80 eyes from 40 cataract patients (mean age: 65.5±7.3 years) who underwent implantation of the Lentis Mplus MIOL in one eye and Acri.Lisa 366 MIOL in the fellow eye. The main outcome measures were refraction; monocular and binocular uncorrected and corrected distance, intermediate, and near visual acuities; monocular and binocular defocus curves; binocular photopic contrast sensitivity function compared to a monofocal intraocular lens (IOL) control group (40 age-matched pseudophakic patients implanted with the AR-40e [Abbott Medical Optics]); and quality of vision questionnaire. RESULTS: Binocular uncorrected visual acuities were 0.12 logMAR (0.76 decimal) or better at all distances measured between 6 m and 33 cm. The Lentis Mplus provided statistically significant better vision than the Acri.Lisa at distances between 2 m and 40 cm, and the Acri.Lisa provided statistically significant better vision than the Lentis Mplus at 33 cm. Binocular defocus curve showed little drop-off at intermediate distances. Photopic contrast sensitivity function for distance and near were similar to the monofocal IOL control group except for higher frequencies. Moderate glare (15%), night vision problems (12.5%), and halos (10%) were reported. Complete independence of spectacles was achieved by 92.5% of patients. CONCLUSIONS: The combination of zonal refractive aspheric and diffractive aspheric MIOLs resulted in excellent uncorrected binocular distance, intermediate, and near vision, with low incidence of significant photic phenomena and high patient satisfaction.

Comparison of the visual and intraocular optical performance of a refractive multifocal IOL with rotational asymmetry and an apodized diffractive multifocal IOL.

PURPOSE: To compare the visual outcomes and intraocular optical quality observed postoperatively in patients implanted with a rotationally asymmetric multifocal intraocular lens (IOL) and an apodized diffractive multifocal IOL. METHODS: Seventy-four consecutive eyes of 40 cataract patients (age range: 36 to 79 years) were divided into two groups: zonal refractive group, 39 eyes implanted with a rotationally asymmetric multifocal IOL (Lentis Mplus LS-312 IOL, Oculentis GmbH); and diffractive group, 35 eyes implanted with an apodized diffractive multifocal IOL (ReSTOR SN6AD3, Alcon Laboratories Inc). Distance and near visual acuity outcomes, contrast sensitivity, intraocular optical quality, and defocus curves were evaluated during 3-month follow-up. Calculation of the intraocular aberrations was performed by subtracting corneal aberrations from total ocular aberrations. RESULTS: Uncorrected near visual acuity and distance-corrected near visual acuity were better in the diffractive group than in the zonal refractive group (P=.01), whereas intermediate visual acuity (defocus +1.00 and +1.50 diopters) was better in the zonal refractive group. Photopic contrast sensitivity was significantly better in the zonal refractive group (P=.04). Wavefront aberrations (total, higher order, tilt, primary coma) were significantly higher in the zonal refractive group than in the diffractive group (P=.02). CONCLUSIONS: Both multifocal IOLs are able to successfully restore visual function after cataract surgery. The zonal refractive multifocal IOL provides better results in contrast sensitivity and intermediate vision, whereas the diffractive multifocal IOL provides better near vision at a closer distance.

Cross-linking in progressive keratoconus using an epithelial debridement or intrastromal pocket technique after previous corneal ring segment implantation.

PURPOSE: To evaluate and compare the clinical and confocal microscopic outcomes achieved with two different procedures for cross-linking (CXL) in eyes with keratoconus: CXL with epithelial debridement and CXL with intrastromal pocket. METHODS: This retrospective study included 27 eyes of 21 patients (age range: 18 to 53 years) diagnosed with keratoconus who underwent implantation of intracorneal ring segments and CXL with two different techniques: CXL with previous epithelial debridement (classic group, 16 eyes) and CXL with intrastromal pocket for riboflavin infusion (pocket group, 11 eyes). Visual, refractive, topographic, aberrometric, and pachymetric data were evaluated during 12-month follow-up. RESULTS: No statistically significant differences between the classic and pocket groups were found in postoperative visual acuity (P ≥.71), refraction (P ≥.15), keratometry (P ≥.28), corneal aberrations (P ≥.13), or central pachymetry (P ≥.21). A statistically significant improvement in uncorrected visual acuity found at 3 months postoperatively in both groups (P<.03) was consistent with a change in manifest sphere. Mean keratometric reduction at 12 months was 0.03 diopters (D) in the classic group (P=.55) and 0.40 D in the pocket group (P=.05). No significant changes in corneal higher order aberrations or central corneal thickness were found in either group (P ≥.14). CONCLUSIONS: Cross-linking surgery with creation of an intrastromal pocket seems to provide similar clinical outcomes compared to the classic CXL technique.

Effects of LASIK on corneal endothelium using the 15-kHz IntraLase femtosecond laser.

PURPOSE: To assess the effects of LASIK with the 15-kHz IntraLase femtosecond laser on corneal endothelium. METHODS: In a prospective, single-center clinical trial, 138 patients (mean age: 32.0 ± 7.1 years [range: 21 to 42 years]) underwent femtosecond LASIK for the correction of myopia -0.75 to -9.00 diopters (D) and cylinder up to 3.25 D. Patients were divided into two groups: contact lens group (n=76) and non-contact lens group (n=62). Pre- and 12-month postoperative specular microscopy of the central corneal endothelium was performed. The integrity of the central endothelium was assessed in terms of endothelial cell density and percentage of hexagonality. RESULTS: In the contact lens group, mean endothelial cell density improved significantly from 3401 ± 292 cells/mm(2) to 3587 ± 262 cells/mm(2) (P<.001) with a mean increase of 5.5%. The percentage of hexagonal cells was statistically significantly higher after surgery (32.5 ± 4.0%) compared with preoperative data (31.0 ± 5.1%) (P=.035). No statistically significant differences were noted regarding mean endothelial cell density (P=.126) or hexagonality (P=.56) before and 1 year after femtosecond LASIK in the non-contact lens group. CONCLUSIONS: Femtosecond LASIK to correct myopia was safe for the corneal endothelium. Improvement in mean endothelial cell density and percentage of hexagonality was observed in the contact lens group.

Epidemiological analysis of an outbreak of diffuse lamellar keratitis.

PURPOSE: To describe the incidence, causes, risk factors, and preventive strategies regarding an outbreak of diffuse lamellar keratitis (DLK). METHODS: Between March and October 2007, an epidemic of DLK was detected in one center. During this period, 6 surgeons performed 1161 LASIK or flap lift procedures. From March to August 2007, data were retrospectively collected corresponding to pre- and postoperative clinical findings and environmental risk factors related to the operating room, auxiliary staff, sterilization, and surgical equipment (phase 1). Incidence and distribution of cases are described. From August to October 2007, a prospective epidemiological study was completed, analyzing the clinical and intraoperative variables associated with the outbreak (phase 2). A plan of action was applied covering a wide range of possible causes. RESULTS: During phase 1, 25.79% of eyes developed DLK. A greater incidence was found in eyes operated on Mondays and a smaller incidence was found when povidone-iodine was used for disinfection of the instruments. Actions taken by the staff to stop the outbreak had no effect, and epidemiologists designed a strategy aimed at addressing all possible weak points and the prospective study for detecting causes. The incidence decreased to 1.87% and a weak significant association was found for sex, atopy, drug allergies, spherical equivalent refraction, and mechanical microkeratome. CONCLUSIONS: Strategies aimed at addressing all possible etiological factors can stop an epidemic of DLK even when a single cause has not been isolated.

Visual and optical performance with two different diffractive multifocal intraocular lenses compared to a monofocal lens.

PURPOSE: To compare the visual acuity outcomes as well as the ocular optical performance of eyes implanted with either a monofocal or one of two diffractive multifocal intraocular lenses (IOLs). METHODS: One hundred two consecutive eyes of 51 bilateral cataract patients (age 49 to 80 years) were divided into three groups: 22 eyes were implanted with a monofocal IOL (monofocal group), 40 eyes with the Acrysof ReSTOR SN6AD3 IOL (ReSTOR group), and 40 eyes with the Acri.Lisa 366D IOL (Acri.Lisa group). Visual acuity and contrast sensitivity were evaluated pre- and postoperatively. Additionally, ocular optical quality and intraocular aberrations were evaluated postoperatively. RESULTS: Significant improvement after surgery in uncorrected and corrected distance and near visual acuity was observed in all three groups (P≤.05). Uncorrected near visual acuity was significantly better in eyes from the ReSTOR and Acri.Lisa groups compared to the monofocal group (P≤.01). Photopic contrast sensitivity was significantly better for the spatial frequency of 3 cycles/degree in the monofocal group (P<.01). Significantly higher values of the ocular Strehl ratio and cutoff modulation transfer function spatial frequency were also found in the Acri.Lisa group (P=.01). An acceptable range of vision between near and distance peaks was observed in the defocus curves of the ReSTOR and Acri.Lisa groups. CONCLUSIONS: The AcrySof ReSTOR and Acri.Lisa 366D IOLs are able to successfully restore near and intermediate visual function after cataract surgery; however, the Acri.Lisa design seems to provide better optical performance. These results need to be confirmed in a randomized, prospective trial.

Refractive outcomes and quality of vision related to an outbreak of diffuse lamellar keratitis.

PURPOSE: To report the impact on visual function and corneal aberrations during an epidemic of diffuse lamellar keratitis (DLK). METHODS: A retrospective, comparative, and consecutive case-control study was performed, involving 418 eyes operated between March and October 2007 in the refractive surgery unit of one center. Eyes were separated into groups: group 1 (DLK group) included 209 eyes that presented with DLK after LASIK and group 2 (control group) included 209 unaffected, consecutive eyes operated from the beginning of the outbreak. Refractive variables and corneal aberrations were compared between the two groups. RESULTS: Visual outcomes were significantly different when comparing control eyes and eyes with DLK grades 3 and 4, but not for eyes with DLK grades 1 and 2. Uncorrected distance visual acuity (UDVA) significantly improved from the third month after DLK was diagnosed (Kruskal-Wallis, P=.02). Corrected distance visual acuity (CDVA) did not decrease significantly with DLK grades 1 and 2 (preoperative CDVA vs 1, 3, and 6 months after diagnosis; Mann-Whitney, P>.05, respectively). At the end of follow-up, UDVA and CDVA were not significantly different between the two groups. Eyes suffering from DLK had significantly increased corneal aberrations, except for spherical and astigmatism aberrations, 3 months after being diagnosed (Kruskal-Wallis, P<.05); however, corneal aberrations were not significantly different between the DLK and control groups (Mann-Whitney, P>.05). CONCLUSIONS: The outbreak of DLK did not induce a significant decrease in global visual outcomes, except in severe cases, and postoperative corneal aberrations were not affected.