Optical quality in vitro and in vivo of an extended depth-of-focus intraocular lens with isofocal design.

PURPOSE: The aim of this study is to compare optical quality results obtained in laboratory analysis (in vitro) versus clinical data (in vivo). METHODS: The optical quality of ISOPure intraocular lens was assessed both in vitro and in vivo using the modulation transfer function (MTF) for 3.0 and 4.5 mm pupil diameters. In vitro measurements were obtained using deflectometer NIMO TRF1504, while in vivo measurements were taken with OPD-Scan III in a set of patients implanted with this lens. Ray tracing techniques were used to determine the MTF and area under MTF curve (MTFa) from the measured wavefront for the isolated lens and for the whole eye. RESULTS: The MTF of the isolated lens obtained under both in vitro and in vivo conditions showed comparable results for both pupil sizes. However, differences were found when comparing the MTF of the whole eye with the lens implanted versus the MTF measured in vitro for 4.5 mm pupil size. Also, the MTFa defocus curve was compared with the defocus curve measured in vivo. CONCLUSION: The defocus curve from the in vivo study aligns closely with the MTFa of the in vitro model, with a useful defocus range of 0.40D. Thus, it is possible to anticipate the visual results of the implanted isofocal lens by using measurements on an optical bench and conducting optical simulations.

Revisiting Javal's rule: a fresh and improved power vector approach according to age.

PURPOSE: The scientific community has established Javal's rule as a model linking refractive (RA) and keratometric (KA) astigmatism since its appearance more than 100 years ago. The aim was to improve the accuracy of this relationship according to subject's age by applying the power vector analysis. Posterior corneal curvature has also been studied. METHODS: The IOLMaster 700 optical biometer was used to measure the corneal thickness and the radius of curvature of the anterior and posterior corneal surfaces. Refractive error was determined by a non-cycloplegic subjective refraction process with trial lenses. Linear regression analyses were applied using J0 and J45 power vector components. An evaluation was carried out according to the subject's age resulting into eight regression relationships for each astigmatic vector component for each relationship. RESULTS: A total of 2254 right eyes from 2254 healthy subjects were evaluated. A trend towards against-the-rule astigmatism (ATR) was found with aging, both for refractive astigmatism (RA) and keratometric astigmatism (KA), with 95.2% of subjects under 20 years old having with-the-rule (WTR) KA, and only 22.8% above 79 years old. The following regression equations were found between RA and KA: [Formula: see text] = 0.73 × [Formula: see text] - 0.18 (R = 0.78) and [Formula: see text] = 0.70 × [Formula: see text] + 0.04 (R = 0.69) and between RA and total corneal astigmatism (TCA): [Formula: see text] = 0.73 × [Formula: see text] + 0.13 (R=0.78) and [Formula: see text] = 0.70 × [Formula: see text] - 0.06 (R = 0.68) for the whole sample, but with sensible differences among age groups, both in the slope and in the intercept. CONCLUSION: Ignoring the age of the subject when using Javal's rule could lead to an error in the final cylinder calculation that would increase in high astigmatisms. Applying this new power vector approach based on subject's age could improve the accuracy of the astigmatism prediction.

Optical power profiles and aberrations of a non-diffractive wavefront-shaping extended depth of focus intraocular lens.

PURPOSE: This study is to evaluate the optical characteristics of a non-diffractive wavefront-shaping intraocular lens which incorporates surface refractive modifications for shaping the wavefront in order to achieve extended depth of focus (EDoF) and to assess whether the nominal power of this IOL influences the attainable add power. METHODS: A commercially available optical bench NIMO TR1504 device (LAMBDA-X, Nivelles, Belgium) was employed to obtain full optical characterization of three non-diffractive EDoF intraocular lenses with + 10 D, + 20 D, and + 30 D powers. After NIMO measurements, data were computed using a custom-made MATLAB program (Mathworks, Inc., Natick, MA, USA) to evaluate the optical quality functions, such as the point spread function (PSF), wavefront profiles, and modulation transfer function (MTF) for two pupil sizes: 3 mm and 4.0 mm. RESULTS: The non-diffractive EDoF intraocular lens showed a central serrated power profile behavior with additions of + 2.00 to + 2.50 D over the nominal power. Higher order aberrations were found to be driven mainly by the spherical aberration, with almost null comatic influence. Optical quality metrics showed good values, better for a 3 mm pupil compared to a 4.5 mm one, as expected. The three IOL powers tested showed a very similar behavior in terms of power and aberrometric profiles, with minimal to null differences related to the nominal power. CONCLUSION: The non-diffractive wavefront-shaping EDoF intraocular lens achieves a near addition up to + 2.50 D aiming for an extended range of vision, almost independently of the base power.

Subjective refraction using power vectors by updating a conventional phoropter with a Stokes lens for continuous astigmatic power generation.

PURPOSE: To implement a pure power vector method for monocular subjective refraction using a regular phoropter with the only modification being the inclusion of a Stokes lens. The proposed methodology was tested with three different Stokes lenses, and the results were compared with conventional clinical refraction procedures. METHODS: Power vector subjective refraction was performed by attaching a Stokes lens to the Risley prism holder. Stokes lenses allow for pure astigmatic compensation in the form of the J0 , J45 components while the spherical lenses in the phoropter allow determination of the spherical component in the form of M (spherical equivalent). The proposed routine is presented step-by-step using three Stokes lenses having different astigmatic powers. RESULTS: Monocular subjective refraction was performed on 26 healthy subjects with a mean age of 44 ± 16 years, mean spherical equivalent of -0.56 D (range -5.50 to +2.38 D) and refractive astigmatism ≤1.50 D. No differences were found between the results obtained with the conventional technique versus the vector-based procedure for the spherical equivalent (p = 0.28) or astigmatic components (p = 0.34). In addition, visual acuity (VA) was equivalent through the refractions measured with the conventional and vector procedures (p = 0.12). Repeatability coefficients for J0 and J45 with the new vector methodology were <0.38 D. CONCLUSIONS: The proposed routine could be helpful for cases where it is difficult to get a valid starting point for conventional refraction (e.g., irregular corneas and media opacities), for testing facilities with limited resources/equipment and/or for motivated clinicians who wish to know about alternative methods of refractive error determination.

Visual and optical quality of enhanced intermediate monofocal versus standard monofocal intraocular lens.

PURPOSE: Intraocular lens designs are constantly evolving, trying to obtain more spectacle independence after cataract surgery. This advantage can be linked to some disadvantages, such as optical quality decrease. For that reason, it is important to assess, not only the amount of vision provided but also the quality of vision once they are implanted. The purpose of the present work was to compare the visual performance between two monofocal intraocular models: a standard model and a monofocal with enhanced intermediate vision lens. METHODS: Prospective, randomized, comparative study. Sixty adult subjects scheduled to undergo bilateral cataract surgery and IOL implantation were randomized to receive one of the two IOLs in both eyes at Miranza IOA, Madrid, Spain (group A: monofocal with enhanced intermediate vision lens and group B: standard monofocal lens). Monocular outcomes (right eyes) determined 1 and 3 months postoperatively were photopic corrected distance visual acuity (CDVA), uncorrected distance visual acuity (UDVA), perceived halo, corrected intermediate-distance contrast sensitivity, and higher-order aberrations. The impact of the new IOL in the postoperative management with autorefraction devices was also evaluated. RESULTS: No differences were found in CDVA between the two groups. Significant differences were detected between the two lenses evaluated in both total HOA (p = 0.028) and internal HOA (p = 0.037). Contrast sensitivity and halometry results obtained at 1 month were similar across the two IOL groups. CONCLUSION: In patients undergoing cataract surgery, monofocal with enhanced intermediate vision IOL offered similar distance performance and contrast sensitivity along with perceived HOA and halos compared with the standard monofocal IOLs tested.

Interocular biometric parameters comparison measured with swept-source technology.

PURPOSE: In the event that any ocular parameter involved in the calculation of intraocular lens power could not be properly measured in one eye, it is important to know whether clinically relevant differences between both eyes can be expected. The aim of this work is to evaluate the symmetry of interocular biometric parameters. METHODS: This was a prospective, cross-sectional study involving 4090 subjects. Patients underwent consecutive swept-source optical biometry performed with an IOLMaster 700 (Carl Zeiss Meditec AG, Jena, Germany). The biometric parameters that were evaluated were: axial length (AL), mean anterior curvature (Rm), anterior chamber depth (ACD), crystalline lens thickness (LT), central corneal thickness (CCT) and white-to-white (WTW). The Chang-Waring chord distance (CWC-D) and the Chang-Waring chord angle (CWC-A) were also evaluated. RESULTS: There is an excellent correlation between both eyes for almost all the biometric parameters under study, with the exception of the CWC. Agreement for AL was better for eyes shorter than 24 mm. The linearity of the OD-vs-OS relationship can be correctly assumed for all parameters (Cusum test: p > 0.05 in all cases). CONCLUSION: There are no clinically significant interocular differences for the biometric parameters under study, although for all of them, except the LT, statistically significant differences did arise. In the case of AL, moderate differences can be expected in eyes larger than 24 mm.

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.

An alternative clinical routine for subjective refraction based on power vectors with trial frames.

PURPOSE: Subjective refraction determines the final point of refractive error assessment in most clinical environments and its foundations have remained unchanged for decades. The purpose of this paper is to compare the results obtained when monocular subjective refraction is assessed in trial frames by a new clinical procedure based on a pure power vector interpretation with conventional clinical refraction procedures. METHODS: An alternative clinical routine is described that uses power vector interpretation with implementation in trial frames. Refractive error is determined in terms of: (i) the spherical equivalent (M component), and (ii) a pair of Jackson Crossed Cylinder lenses oriented at 0°/90° (J0 component) and 45°/135° (J45 component) for determination of astigmatism. This vector subjective refraction result (VR) is compared separately for right and left eyes of 25 subjects (mean age, 35 ± 4 years) against conventional sphero-cylindrical subjective refraction (RX) using a phoropter. The VR procedure was applied with both conventional tumbling E optotypes (VR1) and modified optotypes with oblique orientation (VR2). RESULTS: Bland-Altman plots and intra-class correlation coefficient showed good agreement between VR, and RX (with coefficient values above 0.82) and anova showed no significant differences in any of the power vector components between RX and VR. VR1 and VR2 procedure results were similar (p ≥ 0.77). CONCLUSIONS: The proposed routine determines the three components of refractive error in power vector notation [M, J0 , J45 ], with a refraction time similar to the one used in conventional subjective procedures. The proposed routine could be helpful for inexperienced clinicians and for experienced clinicians in those cases where it is difficult to get a valid starting point for conventional RX (irregular corneas, media opacities, etc.) and for refractive situations/places with inadequate refractive facilities/equipment.

A pilot study on total, corneal, and internal aberrations in insulin-dependent and non-insulin-dependent diabetes mellitus patients.

PURPOSE: To explore the distribution of total, corneal, and internal higher-order aberrations (HOAs) in both insulin-dependent (IDDM) and non-insulin-dependent (NIDDM) diabetic patients. METHODS: Pilot study including seven patients with IDDM (14 eyes) and 11 patients with NIDDM (22 eyes). Ocular HOAs were examined using ray tracing aberrometry (i-Trace, Tracey Technologies Corp., Houston, TX) and the measurements of anterior segment using Scheimpflug imaging (Pentacam, Oculus Inc. Germany). RESULTS: Total HOAs was slightly higher in IDDM (0.634 ± 0.228 µm, 95% IC ± 0.131) than in NIDDM patients (0.527 ± 0.245 µm, 95% IC ± 0.108) (p = 0.267). The greatest contributor for total ocular HOAs was internal vertical coma (Z3 (- 1)) for both diabetic groups. In NIDDM, age and central corneal thickness (CCT) were correlated with total HOAs (p < 0.001, p = 0.0180 respectively); however, anterior chamber volume (ACV) was inversely correlated with total HOAs (p = 0.019). In IDDM, total HOAs were correlated with posterior asphericity (Q) (p = 0.002) and inversely correlated with ageing (p = 0.013). CONCLUSIONS: Diabetic patients showed high values of total and internal vertical coma (Z3 (- 1)). There might be a role for optical quality measurements in monitoring changes due to DM.

Corneal thickness differences between sexes after oxybuprocaine eye drops.

PURPOSE: We aimed to analyze the corneal thickness (CT) values of female and male subjects before and after instillation of oxybuprocaine 0.4% anesthetic eye drops. METHODS: The CT of 30 female subjects and 28 male subjects was measured using scanning-slit corneal topography (Orbscan Topography System II, Orbscan, Inc, Salt Lake City, UT). Measurements were carried out before and 3 minutes after the instillation of oxybuprocaine 0.4% eye drops. RESULTS: The difference between the baseline values and those obtained after anesthesia ranged as follows: male subjects: central, -26 to +24 µm; superior, -24 to +23 µm; inferior, -19 to +20 µm; nasal, -25 to +30 µm; and temporal, -21 to +20 µm; female subjects: central, -16 to +24 µm; superior, -19 to +32 µm; inferior, -14 to +34 µm; nasal, -19 to +33 µm; and temporal, -36 to +16 µm. No significant differences were found in any corneal location in male subjects. The differences were significant at inferior (p = 0.001) and nasal (p = 0.011) corneal sites in female subjects. CONCLUSIONS: Oxybuprocaine anesthetic eye drops induce significant CT increases in female subjects but not in male subjects.

Visual performance of four simultaneous-image multifocal contact lenses under dim and glare conditions.

OBJECTIVE: To assess and compare the effects of four simultaneous-image multifocal contact lenses (SIMCLs), and those with distant-vision-only contact lenses on visual performance in early presbyopes, under dim conditions, including the effects of induced glare. METHODS: In this double-masked crossover study design, 28 presbyopic subjects aged 40 to 46 years were included. All participants were fitted with the four different SIMCLs (Air Optix Aqua Multifocal [AOAM; Alcon], PureVision Multifocal [PM; Bausch & Lomb], Acuvue Oasys for Presbyopia [AOP; Johnson & Johnson Vision], and Biofinity Multifocal [BM; CooperVision]) and with monofocal contact lenses (Air Optix Aqua, Alcon). After 1 month of daily contact lens wearing, each subject's binocular distance visual acuity (BDVA) and binocular distance contrast sensitivity (BDCS) were measured using the Functional Visual Analyzer (Stereo Optical Co., Inc.) under mesopic conditions (3 candela [cd]/m) both with no glare and under the 2 levels of induced glare: 1.0 lux (glare 1) and 28 lux (glare 2). RESULTS: Among the SIMCLs, in terms of BDVA, AOAM and PM outperformed BM and AOP. All contact lenses performed better at level without glare, followed by Glare 1, and with the worst results obtained under glare 2. Binocular distance contrast sensitivity revealed statistically significant differences for 12 cycles per degree (cpd). Among the SIMCLs, post hoc multiple comparison testing revealed that AOAM and PM provided the best BDCS at the three luminance levels. In both cases, BDVA and BDCS at 12 cpd, monofocal contact lenses outperformed all SIMCL ones at all lighting conditions. CONCLUSIONS: Air Optix Aqua Multifocal and PM provided better visual performance than BM and AOP for distance vision with low addition and under dim conditions, but they all provide worse performance than monofocal contact lenses.

Add-on sulcus-based versus primary in-the-bag multifocal intraocular lens: intraindividual study.

PURPOSE: To compare the clinical outcomes of add-on sulcus-based multifocal and standard in-the-bag multifocal intraocular lens (IOL) implantation. METHODS: Twenty-one patients with unilateral monofocal pseudophakia underwent add-on sulcus-based Acri. LISA 536D multifocal IOL (Carl Zeiss Meditec, Jena, Germany) implantation (add-on multifocal IOL group) and contralateral phacoemulsification with in-the-bag Acri.LISA 376D multifocal IOL (Carl Zeiss Meditec) implantation (primary multifocal IOL group). Uncorrected distance visual acuity, uncorrected near visual acuity, corrected distance visual acuity, distance-corrected near visual acuity, photopic (90 cd/m(2)) distance, near contrast sensitivity, mesopic (5 cd/m(2)) distance contrast sensitivity with and without glare, wavefront aberrations, and complications were measured 6 months postoperatively. RESULTS: Primary in-the-bag multifocal IOLs provided slightly but significantly better uncorrected distance visual acuity (0.08 ± 0.10 vs 0.17 ± 0.15 logMAR, P = .028), uncorrected near visual acuity (0.09 ± 0.17 vs 0.18 ± 0.11 logMAR, P = .005), and corrected distance visual acuity (0.01 ± 0.04 vs 0.04 ± 0.05 logMAR, P = .038). There were no significant differences in distance-corrected near visual acuity, photopic or mesopic contrast sensitivity under different conditions, and wavefront aberrations. Complications included pigment dispersion in one eye (4.8%) and pupillary capture in 2 eyes (9.5%) of the add-on multifocal IOL group. CONCLUSIONS: The secondary add-on sulcus-based multifocal IOL provided useful pseudoaccommodation with vision quality similar to the primary in-the-bag multifocal IOL. The technique should be considered in patients diagnosed as having unilateral or bilateral monofocal pseudophakia seeking near spectacle independence.

Visual Outcomes and Patient Satisfaction After Bilateral Refractive Lens Exchange With a Trifocal Intraocular Lens in 5,226 Patients With Presbyopia.

PURPOSE: To assess visual and refractive outcomes and visual function after bilateral RayOne Trifocal toric and nontoric intraocular lens (IOL) (Rayner) implantation in patients with presbyopia. METHODS: Charts of patients with presbyopia who underwent refractive lens exchange with bilateral implantation of the RayOne Trifocal IOL (toric and non-toric) were retrospectively reviewed. Visual and refractive outcomes were evaluated at 3 months. Patient satisfaction, spectacle independence, and visual disturbance profile were assessed by questionnaires. RESULTS: A total of 5,226 patients were assigned to one of two groups: 1,010 patients had toric IOL implantation (toric group) and 4,216 patients received the non-toric model (non-toric group). Mean ± standard deviation visual acuity at 3 months for the toric group was binocular uncorrected distance visual acuity (UDVA) of 0.07 ± 0.11 logMAR, monocular corrected distance visual acuity (CDVA) of 0.05 ± 0.07 logMAR, binocular uncorrected near visual acuity (UNVA) at 40 cm of 0.10 ± 0.09 logMAR, binocular uncorrected intermediate visual acuity (UIVA) at 40 cm of 0.13 ± 0.12 logMAR, postoperative spherical equivalent (SE) of -0.21 ± 0.47 diopters (D), and cylinder of -0.34 ± 0.40 D. The non-toric group had binocular UDVA of 0.04 ± 0.08 logMAR, monocular CDVA of 0.05 ± 0.07 logMAR, binocular UNVA of 0.10 ± 0.08 logMAR, binocular UIVA of 0.13 ± 0.11 logMAR, SE of -0.08 ± 0.38 D, and cylinder of -0.28 ± 0.34 D. No statistically significant differences were found in achieving spectacle independence and there were high levels of satisfaction in both groups. CONCLUSIONS: In this retrospective analysis with more than 5,000 patients, both the toric and non-toric RayOne Trifocal IOL models provided good visual performance at all distances, resulting in excellent levels of spectacle independence and patient satisfaction. [J Refract Surg. 2024;40(7):e468-e479.].

Intra-eye visual function comparison with and without a central hole contact lens-based system: potential applications to ICL design.

PURPOSE: To evaluate the effects of a central hole contact lens-based design on visual performance and to compare it with the standard version of that same contact lens without the hole (non-hole scenario). METHODS: The visual performance of 10 myopic patients wearing either a central hole myopic contact lens or its corresponding standard version (non-hole contact lens) was assessed on the same eye. Monocular corrected distance visual acuity was measured under photopic conditions and monocular contrast sensitivity was measured under both photopic and mesopic conditions and higher-order ocular aberrations using Hartmann-Shack aberrometry. An in vitro optical analysis of both contact lenses was performed and a symptoms questionnaire was administered to the participants. RESULTS: No statistically significant differences in terms of corrected distance visual acuity were found: -0.091 and -0.098 logMAR for the hole and non-hole contact lenses, respectively (P > .05). Contrast sensitivity was comparable between lenses and no differences were found for specific spatial frequencies or a particular luminance level (P > .05). The hole contact lenses provided excellent outcomes, essentially equivalent to those of non-hole contact lenses, even in terms of subjective symptoms such as glare or halo. In vivo and in vitro optical quality analysis revealed no statistically significant differences between the hole and the non-hole contact lenses for either pupil size (P > .1). CONCLUSION: A contact lens having a central hole provides good visual and optical quality outcomes comparable to those yielded by the same lens without a hole. The results suggest that the impact of a central hole may be clinically negligible.

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.

Diurnal variations in visual performance for disposable contact lenses.

PURPOSE: The purpose of this study is to compare the visual performance provided by different daily disposable contact lenses and to analyze its variation over time. METHODS: Visual performance was evaluated in terms of visual acuity (VA) and contrast sensitivity (CS) in 15 myopic subjects (-0.50 to -4.00 diopters) who had been previously fitted with each one of the following seven types of soft contact lenses: DAILIES TOTAL1 (Alcon, Forth Worth, TX), DAILIES AquaComfort Plus (Alcon), 1-DAY ACUVUE TruEye (Johnson & Johnson Vision Care, Jacksonville, FL), 1-DAY ACUVUE MOIST (Johnson & Johnson Vision Care), SofLens daily disposable (Bausch & Lomb, Rochester, NY), Proclear 1 Day (CooperVision, Fairport, NY), and Clariti 1-Day (Sauflon, Twickenham, United Kingdom). We measured VA at three contrast levels (10%, 50%, and 100%) and CS for three spatial frequencies (10, 20, and 25 cycles/degree). These measurements were performed at 2-hr intervals during a 12-hr period of continuous wearing. Measurements were also performed with ophthalmic lenses before contact lens fitting. RESULTS: Two-way analysis of variance (ANOVA) results revealed significant differences across the lens types and over time for low-contrast VA only. For high- and medium-contrast VA, ophthalmic lens performed better than the contact lenses after 12 hr of use (without statistical differences among the contact lenses). Contrast sensitivity values also showed differences across lenses for the three spatial frequencies under analysis. For each particular lens type, no CS variations were observed with wearing time. Although some of the differences were not statistically significant, we found that, for many of the VA and CS measures, ophthalmic lens and DAILIES TOTAL1 yielded better values than the 1-DAY ACUVUE TruEye and Clariti 1-Day. CONCLUSIONS: Assessing VA at different contrasts and CS measurements allowed us to perform a visual function evaluation. Contact lens characteristics such as material and water content, among others, may be the cause of the differences in visual performance that emerged from this study. Our findings provide useful information for contact lens practitioners.

Visual performance of two simultaneous vision multifocal contact lenses.

PURPOSE: To evaluate and compare the visual performance of two simultaneous vision multifocal contact lenses (CLs). METHODS: In this cross-over study design 20 presbyopic subjects were fitted with two different simultaneous vision multifocal CLs (the PureVision Multifocal Low Add and Acuvue Oasys for Presbyopia) in random order. After 1 month, binocular distance visual acuity (BDVA) under photopic (85 cd/m(2)) and mesopic (3 cd/m(2)) conditions, binocular near visual acuity (BNVA), binocular distance contrast sensitivity function (CSF) under photopic and mesopic conditions, binocular near CSF and defocus curve were measured. Subjects were then refitted with the alternative correction and the procedure was repeated. RESULTS: Mean BDVA under photopic conditions was similar for the Acuvue Oasys for Presbyopia and PureVision Multifocal Low Add: 0.01 ± 0.08 and 0.00 ± 0.08 logMAR, respectively (P = 0.45). Under mesopic conditions the values of BDVA were 0.20 ± 0.58 and 0.11 ± 0.09 logMAR, respectively (P = 0.005). Mean BNVA was 0.20 ± 0.05 and 0.15 ± 0.08 logMAR for the Acuvue Oasys and PureVision Low Add, respectively (P = 0.06). Binocular distance CSF testing revealed no statistically significant differences between lenses under photopic, mesopic or near conditions. Both lenses provided a comparable intermediate visual acuity. CONCLUSIONS: Both simultaneous vision multifocal CLs provided adequate distance visual quality under photopic and mesopic conditions, and better visual acuity was provided under mesopic conditions for the Purevision lens. Both lenses provided adequate visual performance at intermediate distance, but the near visual acuity appears to be insufficient for early presbyopes who require a moderately demanding near visual quality.

On-eye optical quality of daily disposable contact lenses for different wearing times.

PURPOSE: To quantify the optical quality of various daily disposable contact lenses in vivo and to ascertain its variation in terms of wearing time by means of objective non-invasive determination of wavefront patterns. METHODS: The crx1 adaptive-optics system was used to measure the wavefront aberrations in 15 myopic eyes before and at 2-h intervals after contact lens fitting, over a 12-h wearing period. Seven types of contact lenses having different material, water content and lens design were evaluated in this study: Dailies Total1, Dailies AquaComfort Plus, Proclear 1 Day, 1-Day Acuvue TruEye, 1-Day Acuvue moist, SofLens daily disposable and Clariti 1-Day. The aberration data were analysed by fitting Zernike polynomials up to the 5th-order for 3 and 5-mm pupils. The optical quality under each condition and at each point in time was described by means of the Root-Mean-Square (RMS) value of wavefront aberration, Modulation Transfer Function (MTF), Point Spread Function and cut-off spatial frequency. RESULTS: A RMS increase was observed after contact lens fitting as well as over time, both for a 3-mm and a 5-mm pupil. Each type of lens induced a different amount of wavefront aberrations, which vary over time also in a different manner. Dailies Total1 showed the lowest RMS values both at baseline and at the end of the day. In addition, Dailies Total1 provided the best MTF out of all the contact lenses that were assessed. These observations were reflected in higher cut-off spatial frequencies and visual resolution both at baseline and after 12 h of wearing time. CONCLUSIONS: Aberrometry makes it possible to analyse accurately and in vivo the optical quality of contact lenses and to assess how lenses having different characteristics - such as material or water content - behave for different wearing times. These variations across contact lenses may result in differences in visual performance.

Influence of Intravitreal Therapy on Choroidal Thickness in Patients with Diabetic Macular Edema.

OBJECTIVE: This study aimed to analyze the variation in subfoveal choroidal thickness (SFCT) and its relationship with the variation in central macular thickness (CME) in response to intravitreal therapy with an antiangiogenic (anti-VEGF) drug or corticosteroid in type 2 diabetic patients with diabetic macular edema (DME). MATERIAL AND METHODS: This retrospective study included 70 eyes of 35 patients: 26 eyes received 4-5 intravitreal injections of aflibercept, 26 eyes were treated with a single intravitreal implant injection of dexamethasone, and 18 eyes without DME did not receive intravitreal therapy. SPECTRALIS® optical coherence tomography (OCT) (Heidelberg Engineering, Heidelberg, Germany) was used to measure the SFCT and CME before and at the end of the follow-up period. RESULTS: The mean reductions in CME were 18.8 +/- 14.7% (aflibercept) and 29.7 +/- 16.9% (dexamethasone). The mean reductions in SFCT were 13.8 +/- 13.1% (aflibercept) and 19.5 +/- 9.6% (dexamethasone). The lowering effects of both parameters were significantly greater in the group treated with the dexamethasone implant (p = 0.022 and p = 0.046 for CMT and SFCT, respectively). Both therapies significantly decreased both CME and SFCT, independent of factors such as age, sex, previous intravitreal therapy, antidiabetic treatment, and the time of diabetes progression. There were no changes in the mean values of CME and SFCT in the untreated eyes. CONCLUSIONS: SFCT significantly decreased in response to intravitreal therapy with anti-VEGF or corticosteroids, irrespective of age, sex, previous intravitreal therapy, antidiabetic treatment, and the time of diabetes progression. There was a correlation between the changes in CME and SFCT after intravitreal therapy with aflibercept or dexamethasone implantation. SFCT was not a good predictor of the CME response but could be used to monitor the response to treatment. Local intravitreal therapy only affected the treated eye.