Previous Refractive Surgery Research Articles

Intraocular Lens Power Calculations in Eyes with Previous Corneal Refractive Surgery: Review and Expert Opinion

Intraocular lens (IOL) power calculations are less accurate in eyes that have undergone corneal refractive surgery. A wide range of methods have been proposed. We reviewed the methods and outcomes of IOL power calculations in eyes with previous LASIK, excimer laser photorefractive keratectomy (PRK), or radial keratotomy (RK). The PubMed database was searched for articles that (1) discuss methods and outcomes of IOL power calculation in eyes with previous corneal refractive surgery and (2) evaluate the outcomes of toric, multifocal, or extended depth-of-focus (EDOF) IOLs in these eyes. We excluded review articles, case reports or case studies, and non-English reports. Seventy full-text articles were included in this review. Three categories of methods exist based on whether and how they use historical data acquired before the corneal refractive surgery. The American Society of Cataract and Refractive Surgery (ASCRS) postrefractive IOL calculator incorporates many commonly used methods. In eyes with previous myopic LASIK or PRK, hyperopic LASIK or PRK, and RK, 0% to 85%, 38.1% to 71.9%, and 29% to 87.5% of eyes, respectively, showed refractive prediction errors within ±0.5 diopter (D); in eyes with toric IOL implantation that met certain inclusion criteria, 80%, 84%, and 69% of eyes, respectively, achieved postoperative astigmatism of 0.50 D or less. Intraocular lenses with negative spherical aberration (SA) will reduce the positive corneal spherical aberration induced in eyes by myopic LASIK or PRK or by RK. Intraocular lenses with 0 SA on average best match corneal SA in eyes with prior hyperopic LASIK or PRK. Studies have reported excellent outcomes of postrefractive eyes implanted with multifocal or EDOF IOLs; however, corneal topographic enrollment criteria were not specified. Despite availability of new measurement technologies and development of new IOL calculation formulas, further advances are needed to improve outcomes of cataract surgery in eyes that have undergone corneal refractive surgery. Tools like the ASCRS postrefractive IOL calculator are useful for the clinician by incorporating a variety of formulas. Toric, EDOF, and multifocal IOLs may provideexcellent outcomes in selected cases that meet certain corneal topographic criteria.

Persistent Hypotony and Annular Ciliochoroidal Detachment After Microhook Ab Interno Trabeculotomy.

To report persistent hypotony after μLOT, a minimally invasive glaucoma surgery (MIGS). This observational case series included 4 consecutive cases (3 men, 1 woman; mean age, 48.8±15.1 y) of persistent hypotony that developed after μLOT between May 2015 and March 2018. The patients' data and surgical results were obtained from the medical charts. All patients had open-angle glaucoma (2 juvenile, 1 primary, and 1 pigmentary) and were myopic (axial lengths, >24 mm). Two patients had undergone previous refractive surgery. μLOT alone was performed in 2 cases and combined with cataract surgery in 2 cases. In all cases, hypotony below 5 mm Hg was recorded 1 day postoperatively and sustained. In all cases, ultrasound biomicroscopy showed an annular CCD; communication between the anterior chamber and suprachoroidal space was detected in 3 of 4 cases. The hypotony resolved in 3 of the 4 cases from 2 to 8 months postoperatively, that is, spontaneously in 2 cases (cases 1 and 4) and after sulfur hexafluoride gas injection into the anterior chamber in 1 case (case 2). CCD resolution accompanied remarkedly high intraocular pressure, which required filtration surgeries. The incidence of persistent hypotony was 0.7% (4/547 eyes). After MIGS, persistent hypotony because of CCD rarely occurs. Increased uveoscleral outflow because of LOT or creation of a cyclodialysis cleft by traction of the pectinate ligament can be a mechanism of CCD development. Young age and myopia can be risks for cyclodialysis cleft formation and hypotony maculopathy after MIGS.

Refractive and Visual Outcomes After Implantation of a Secondary Toric Sulcus Intraocular Lenses.

PurposeTo evaluate the rotational stability, visual acuity and refractive error after sulcus implantation of a secondary toric IOL.SettingOne clinical practice in Haugesund, Norway.DesignNon-interventional single-arm diagnostic study.MethodsEligible subjects who had previous successful primary cataract or refractive lens exchange surgery in one or both eyes and the AddOn® secondary toric IOL implanted in the sulcus were evaluated at a single postoperative diagnostic visit to measure visual outcomes. Subjects with surgical complications (either primary or secondary) or pathology that would affect best-corrected visual acuity (eg, amblyopia) were excluded. Clinical evaluations at the diagnostic visit included measurement of visual acuity, manifest refraction and IOL orientation.ResultsEighteen eyes were evaluated. After secondary IOL implantation, mean residual refractive astigmatism was significantly reduced (1.66 ± 0.92 to 0.32 ± 0.25 D). There was no appreciable change in the spherical equivalent refraction. Sixteen of 18 eyes (89%) had residual refractive astigmatism ≤0.50D, and no eye had more than 0.75D after secondary IOL implantation. Mean UCVA was 0.00 ± 0.03 logMAR, with no eyes worse than 0.10. Mean BCVA was −0.05 ± 0.03 logMAR (20/20+2), with all eyes having BCVA of 0.00 logMAR. The mean change in orientation was near zero, with a mean absolute change of 4.9 ± 3.7 degrees. Sixteen of 18 eyes (89%) had a lens orientation ≤10 degrees from intended, with no eye oriented more than 13 degrees from intended.ConclusionThe AddOn® toric sulcus IOL significantly reduced postoperative refractive astigmatism in patients with high astigmatism after their primary cataract or RLE surgery, providing very good uncorrected distance vision.

Total keratometry in intraocular lens power calculations in eyes with previous laser refractive surgery.

Intraocular lens (IOL) calculations in post-refractive cases remain a concern. Our study identifies improved options for surgeons. To evaluate and compare the prediction accuracy of IOL power calculation methods after previous laser refractive surgery using standard keratometry (SK), measured posterior corneal astigmatism (PCA) and total keratometry (TK). Retrospective consecutive cohort. A total of 50 consecutive patients (72 eyes) at a private institution who underwent cataract surgery with prior laser refractive procedures. Methods using SK included ASCRS mean, Barrett True-K no history, Haigis-L and Shammas IOL formulae. Barrett True-K using posterior values (True K TK), Haigis and Holladay 1 Double-K methods using TK were also assessed. Post-surgery refraction was undertaken at minimum 3 weeks following surgery. Arithmetic and absolute IOL refractive prediction errors, variances in mean arithmetic IOL prediction error, and percentage of eyes within ±0.25D, ±0.50D, ±0.75D and ±1.00D of refractive prediction errors were compared. The Barrett True-K (TK) provided the lowest mean refractive prediction error (RPE) and variance for both prior myopes and hyperopes undergoing cataract surgery. The Barrett True-K (TK) exhibited the highest percentages of eyes within ±0.50D, ±0.75D and ±1.00D of the RPE compared to other formulae for prior myopic patients. Accuracy of IOL power calculations in post-laser eyes can be improved by the addition of posterior corneal values as measured by the IOLMaster 700. The use of total keratometry may supplement outcomes when no prior refraction history is known.

Outcome of toric intraocular lenses implanted in eyes with previous corneal refractive surgery.

To evaluate the outcome of toric intraocular lens (IOL) implantation in eyes with previous laser in situ keratomileusis/photorefractive keratectomy (LASIK/PRK). Cullen Eye Institute, Baylor College of Medicine, Houston, Texas, USA. Retrospective case series. Consecutive cases that had previous myopic or hyperopic LASIK/PRK and had undergone cataract surgery with toric IOL implantation were retrospectively reviewed. Included were eyes that had (1) preoperative ocular biometry measurements with the Lenstar, (2) no intraoperative or postoperative complications, and (3) available postoperative manifest refraction at ≥3 weeks with corrected distance visual acuity of 20/30 or better. Vector analysis was used to assess the preoperative corneal and postoperative refractive astigmatism. In 56 eyes with previous myopic LASIK/PRK and 19 eyes with previous hyperopic LASIK/PRK, respectively, the mean magnitudes of corneal astigmatism were 1.34 ± 0.62 diopters (D) and 1.66 ± 0.80 D, 5% and 0% of eyes had anterior corneal astigmatism ≤0.50 D, and the centroid values were 0.31 D at 19 degrees ± 1.45 D and 0.74 D at 92 degrees ± 1.72 D preoperatively. Postoperatively, the mean magnitudes of refractive astigmatism were 0.36 ± 0.31 D and 0.34 ± 0.34 D, 80% and 84% of eyes had refractive astigmatism of ≤0.50 D, and the centroid values were 0.12 D at 152 degrees ± 0.46 D and 0.05 D at 172 degrees ± 0.48 D (all P < .05). Toric IOLs were effective to correct preexisting corneal astigmatism in eyes with previous excimer laser corneal refractive surgery.

The influence of corneal astigmatism on retinal nerve fiber layer thickness and optic nerve head parameter measurements by optical coherence tomography

Abstract Background Astigmatism is a worldwide common ocular disorder. Total astigmatism is mainly driven by corneal astigmatism (CA), which occurs due to an irregular shape of the cornea. In eyes with astigmatism, retinal images can be distorted, and the image size could vary according to the axis of astigmatism assessed with computer-based methodology in astigmatic eyes. Objective to evaluate the influence of corneal astigmatism on the RNFL thickness and ONH parameters obtained by spectral-domain OCT. Patients and Methods 40 patient chosen from outpatient ophthalmology of Ain Shams University Hospitals and Om El¬_Massrein General Hospital and classified in two groups, the study group (high astigmatic patients ≥ 3 diopter) and control group (normal astigmatism&amp;lt; 3 diopter) with no significant change in the age and sex. All cases were free of any ocular diseases with no past history of medical importance (DM, HTN or any neurological diseases), all this cases never had any previous refractive surgery or any retinal lesion. Results In this study all cases had average IOP &amp;gt; 21 mmhg, and randomly selected from the outpatient clinic. The study group had thinner retinal nerve fiber layer in temporal quadrant and larger disc area than the control group. These study support the concept that corneal astigmatism has an effect on retinal nerve fiber layer thickness and optic nerve head parameters. Conclusion In our study, we compare between the OCT pattern of retinal nerve fiber layer thickness (total, superior, nasal and inferior quadrants) and the optic nerve head parameters (cup area, disc area, vertical and horizontal C/D ratio) in the high astigmatic patients (≥ 3 diopter) and normal astigmatism &amp;lt; 3 diopter.

Using a multilayer perceptron in intraocular lens power calculation

To determine the capabilities of a multilayer perceptron (MLP) for calculating the power of an intraocular lens (IOL) to be implanted and in achieving a given postoperative stable refraction. Cuban Institute of Ophthalmology, Havana, Cuba. Retrospective review. The study comprised data of patients who had uneventful phacoemulsification cataract surgery with implantation of a biconvex acrylic foldable IOL (type RYCF, model Ocuflex) in the capsular bag over 6years. Exclusion criteria were previous intraocular or refractive corneal surgery, any corneal disease, pathological or complicated cataracts, intraoperative complications, preoperative astigmatism beyond 3.0 diopters (D), postoperative corrected distance visual acuity worse than 20/40, missing postoperative refractive information, eyes with an axial length (AL) shorter than 19.36mm, eyes with an AL longer than 27.0mm, average corneal keratometry (K) power lower than 36.0 D or higher than 50.9 D, and refractive surprises greater than ±3.0 D. The data were used to train an MLP to predict the value of the IOL power required for attaining a given postoperative refraction. Using AL, K value, and predicted and real postoperative refraction as input data, the output of the MLP was the IOL power. The study comprised 15 728 eyes of 15 728 patients. The trained neural networks predicted the value of the implanted IOL with an error less than 0.5 D in more than 95% of patients, even for a case in which a surgeon was not included in the training process. The accuracy attained by the trained MLP is high, indicating the feasibility of a prospective study leading to a new method of predicting the IOL power in refractive surgery with an error lower than the current prediction methods.

Evaluation of total keratometry and its accuracy for intraocular lens power calculation in eyes after corneal refractive surgery

To compare the accuracy of total keratometry (TK) and standard keratometry (K) from a swept-source optical coherence tomography biometer for intraocular lens (IOL) power calculation in eyes with previous corneal refractive surgery. Cullen Eye Institute, Baylor College of Medicine, Houston, Texas, USA. Retrospective case series. The differences between the TK and K and their association with K were assessed. For IOL power calculation, combinations of 1) K with Haigis, Haigis-L, and Barrett True-K, and 2) TK with Haigis (Haigis-TK) were used. The mean absolute error (MAE) and the percentages of eyes within prediction errors of ± 0.50 diopters (D), ± 1.00 D, and ± 2.00 D were calculated. The study comprised 129 eyes. For Haigis, Haigis-L, Barrett True-K, and Haigis-TK, respectively, the MAEs were 0.72 D, 0.61 D, 0.54 D, and 0.50 D in the myopic laser insitu keratomileusis (LASIK)/photorefractive keratectomy (PRK) group, and 0.74 D, 0.68 D, 0.71 D, and 0.70 D in hyperopic LASIK/PRK group. For the radial keratotomy (RK) eyes, the MAEs were 0.66 D, 0.71 D, and 0.72 D for the Haigis, Barrett True-K, and Haigis-TK formulas, respectively. In the myopic LASIK/PRK group, the Barrett True-K and Haigis-TK produced significantly lower MAEs than did Haigis (P<.05). In the hyperopic LASIK/PRK and RK groups, there were no significant differences between the formulas in MAEs and percentages of eyes within the above prediction errors. The performance of the combination of Haigis and TK in refractive prediction was comparable with Haigis-L and Barrett True-K in eyes with previous corneal refractive surgery.

Transepithelial Topography-Guided Ablation Assisted by Epithelial Thickness Mapping for Treatment of Regression After Myopic Refractive Surgery

To evaluate the outcomes of transepithelial, topography-guided, epithelial mapping-assisted ablation in the treatment of regression after myopic refractive surgery. A retrospective consecutive case series of 70 eyes of 52 patients with regression after previous corneal refractive surgery for treatment of myopic and compound myopic astigmatism underwent re-treatment using transepithelial topography-guided and epithelial mapping-assisted custom ablation with a wide and smooth transition zone design. The ablation profile was based on data from corneal topography, whereas the epithelial ablation depth was decided by corneal epithelial mapping obtained by optical coherence tomography. The mean follow-up time after re-treatment was 13.6 ± 9.4 months (range: 6 to 51 months). At the patients' last follow-up visit, 98.5% and 76.5% had uncorrected distance visual acuity of 20/40 and 20/20 or better. Safety and efficacy indexes were 1.05 and 0.92, respectively. The mean spherical equivalent was reduced from -1.10 ± 0.65 to -0.16 ± 0.34 diopters. Both total root mean square, odd-order, and even-order higher order aberrations improved significantly (P = .021, .040, and .030, respectively), whereas corneal asphericity remained unchanged (P = .662). Epithelial thickness profile showed significant smoothing between the central 2-mm and 2- to 5-mm paracentral areas. Transepithelial topography-guided and epithelial mapping-assisted custom re-treatment with a wide and smooth transition zone design is safe and effective for addressing myopic regression in patients who have previously undergone myopic refractive surgery. [J Refract Surg. 2019;35(8):525-533.].

ASCRS calculator formula accuracy in multifocal intraocular lens implantation in hyperopic corneal refractive laser surgery eyes

To evaluate the accuracy of different intraocular lens (IOL) power calculation formulas available on the American Society of Cataract and Refractive Surgery calculator in calculating multifocal IOL power in eyes with previous hyperopic corneal refractive laser surgery. Retrospective case series. Amsterdam University Medical Center, University of Amsterdam, and Retina Total Eye Care, Driebergen, the Netherlands. This study compared the accuracy of 3 formulas using historical refractive data (ie, Masket, modified Masket, and Barrett True-K) and 3 formulas using no previous refractive data (ie, Shammas, Haigis-L, and Barrett True-K no-history). Sixty-four eyes were included. The variance of the prediction error of the various formulas was similar and ranged from 0.27 D2 to 0.33 D2 (P=.99). The modified Masket formula had a significantly higher median absolute prediction error than the Masket formula, Barrett True-K formula, and mean value of all formulas (P<.001). All formulas showed comparable accuracy in predicting IOL power in eyes after hyperopic corneal refractive laser surgery except for the modified Masket formula, which performed less accurately than the Masket formula, Barrett True-K formula, and mean value of all formulas.

Visual Outcomes after Topography-Guided Femtosecond LASIK in Virgin Eyes

Background: Laser vision correction has been established over the last 2 decades as a safe and effective intervention, with Laser-assisted in situ keratomileusis (LASIK), being one of the main techniques practiced globally. Femtosecond laser-assisted LASIK has become a popularized modification over the last decade and over the standard LASIK technique utilizing mechanical microkeratomes. A spherical ablation profiles performed by “wave front optimized” have been employed to reduce spherical aberration associated with myopic corrections. Aim of the Work: To evaluate the quality and efficacy of topography-guided femtosecond lasik in virgin eyes with myopia, hypermetropia and astigmatism. Patients and Methods: This comparative prospective study was conducted on 60 eyes of 30 Egyptian patients with comparing preoperative and postoperative outcomes. Eyes with myopia (-1.0 up to -8.0 diopters) or hypermetropia (+1.0 up to +5.0 diopters) or astigmatism (up to 5.0 diopters) or less. Eyes with central corneal thickness (CCT) of 500 microns or more. Eyes at risk for developing post-refractive corneal ectasia, such as keratoconus, keratoconus suspect, previous refractive surgery, corneal dystrophy, corneal guttae or opacities, any previous eye surgery e.g.:pseudophakic patients, retinal detachment surgery, all eyes were normal for example no cataract, no glaucoma, no retinal pathology and no previous trauma. Results: Our study was performed on sixty eyes of thirty Egyptian patients. Sixty eyes of thirty patients underwent LASIK using T-CAT. Seventeen patients were females and thirteen were males. The average age of the patients was 24.8 year ±5.45 standard deviation (SD). The average spherical error was -3.09 D ±2.33 SD. The average cylinder error was -1.02 D ±1.02 SD. Conclusion: The results showed that there were statistically significant differences between preoperative BCVA and postoperative UCVA with a good safety and efficacy profile with T-CAT lasik as no patient loss even one line and 80% of cases gaining at least one line postoperative. The surgery was associated with higher values of high order aberrations after surgery than before surgery.

Multifocal intraocular lens implantation after previous hyperopic corneal refractive laser surgery

To describe the outcomes in terms of the refraction and visual acuity of multifocal intraocular lens (IOL) implantation in patients with previous hyperopic corneal refractive laser surgery. Academic Medical Center, University of Amsterdam, Amsterdam, and Retina Total Eye Care, Driebergen, the Netherlands. Retrospective case series. Results were analyzed 3months after implantation of a multifocal IOL (Acrysof Restor SN6AD1) in patients after previous corneal refractive laser surgery for hyperopia. The primary outcome measures were uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), and refraction. The secondary outcome measures were the number of laser enhancements and posterior capsule opacification (PCO) rates. Forty eyes of 40 patients were included. Sixteen eyes (40.0%) had lens extraction because of cataract, and 24 eyes (60.0%) had refractive lens exchange. The mean postoperative UDVA was 0.16 logarithm of the minimum angle of resolution (logMAR)±0.18 (SD), and the mean postoperative CDVA was 0.01±0.08 logMAR. The mean postoperative spherical equivalent was 0.04±0.92 diopter (D). Twenty-five eyes (62.5%) were within ±0.50 D of emmetropia, and 35 eyes (87.5%) were within ±1.0 D of emmetropia. Nine eyes (22.5%) had a laser enhancement because of a residual refraction error. Eleven eyes (27.5%) had a neodymium:YAG laser capsulotomy because of PCO. In general, multifocal IOL implantation after corneal refractive laser surgery for hyperopia resulted in good visual acuity and refraction. The magnitude of previous hyperopia did not influence the refractive predictability.

Simulation of the Effect of Different Presbyopia-Correcting Intraocular Lenses With Eyes With Previous Laser Refractive Surgery.

To simulate the optical performance of three presbyopia-correcting intraocular lenses (IOLs) implanted in eyes with previous laser refractive surgery. A simulation of the through-focus modulation transfer function (MTF) was performed for three presbyopia-correcting IOLs (Mplus, Oculentis GmbH, Berlin, Germany; Symfony, Johnson & Johnson Vision, Santa Ana, CA; and Mini Well, SIFI S.p.A., Lavinaio, Italy) in one eye with previous myopic LASIK and another with hyperopic LASIK. Real topographic data and the wavefront aberration profile of each IOL obtained with a Hartmann-Shack sensor were used. In the eye with myopic LASIK, all IOLs lost optical quality at near and intermediate distances for 4- and 4.7-mm pupil size. For 3-mm pupil size, the Mini Well IOL showed the best intermediate and near MTF and maintained the far focus independently of the pupil. In the eye with hyperopic LASIK, the Mini Well IOL showed an intermediate, distance, and -4.00-diopter (D) foci for all pupils. The Symfony IOL showed a depth of focus at far and intermediate distance for 3-mm and a focus at -2.50 D in the rest. The Mplus showed a focus of -4.50 and -3.00 D for the 3- and 4-mm pupil, respectively. The Mini Well and Symfony IOLs seem to work better than the Mplus IOL in eyes with previous myopic LASIK. With previous hyperopic LASIK, the Mini Well IOL seems to be able to provide acceptable near, intermediate, and far foci for all pupil sizes. These findings should be confirmed in future clinical studies. [J Refract Surg. 2018;34(4):222-227.].

Central corneal thickness and intraocular pressure relationship in eyes with and without previous lasik - Comparison of Goldmann applanation tonometer with pneumatonometer.

To investigate central corneal thickness (CCT) and intraocular pressure (IOP) relationship in eyes with and without previous corneal laser refractive surgery and to compare the estimates of two different tonometersGoldmann applanation and pneumatonometer. The study population included 234 glaucoma suspects who were referred to the glaucoma clinic with cup/disc ratios greater than 0.4, asymmetric cupping, and/or IOP greater than 22 mmHg during routine eye examination. Of those, 84 had previous myopic laser-assisted in situ keratomileusis (LASIK) (Group 1) while 150 of them did not (Group 2). CCT was measured by using optical coherence tomography (OCT) and IOP with both Goldmann applanation tonometer (GAT) and pneumatonometer (PT). In both groups, the difference between IOP estimates of two different tonometers and the relationship between CCT and IOP were analyzed. In eyes with previous LASIK, GAT measured IOP significantly lower than PT (mean difference of 3.81.9 mmHg, p<0.0001). In eyes with virgin corneas, IOP estimates of GAT or PT were not different from each other (19.92.8 versus 19.92.2 mmHg, respectively, p=0.81). In both groups, there was a significant positive correlation between CCT and IOP estimates of GAT (R=0.29, p=0.007 in eyes with LASIK and R=0.38, p<0.0001 in those without), while no similar relationship was present between CCT with those of PT (R=0.03, p=0.76 in eyes with LASIK and R=0.03, p=0.69 in those without). In eyes with previous LASIK, GAT measured IOP significantly lower than PT. Because IOP estimates of PT were found to be independent from CCT in all of the study eyes, this device was considered to be a more reliable method of IOP estimation than GAT in eyes with and without previous LASIK. (Eur J Ophthalmol 2005; 15: 81-8).

Retrospective Outcomes and Patient Satisfaction with Previous Refractive Surgery and Multifocal Intraocular Lens Implantation

Aim: To report pre, post-surgical visual outcomes and satisfaction after cataract or clear lens surgery, with multifocal intraocular lens implantation, in patients with previous refractive surgery. Methods: Retrospective study of postoperative outcomes and satisfaction in patients with previous refractive surgery and Multifocal Intraocular Lens (MF-IOL) implantation. Preoperative variables: time LASIK performed, visual acuity, Uncorrected (UCVA) and best corrected (BCVA), Spherical Equivalent (SE), Addition (Add), SimK and pachymetry, pupillometry. Postoperative data: UCVA, BCVA, SE, and Add. Results grouped as: general, cataracts vs. clear lens (CL), segmented vs. trifocal MF-IOL, and myopes vs. hyperopes. Patients completed a satisfaction and difficulty questionnaire (Q). Data was analyzed using paired student-t test, with Bonferroni adjustment. Linear regression analysis between normally distributed preoperative variables and survey data were reported. Results: Mean results recorded for 30 eyes, mean age 52.3 ± 6.2 years; pre-LASIK SE -2.8 ± 3.8D, segmented MF-IOL in 22 eyes and 8 eyes with trifocal IOL. Pre/postoperative results: SE: -0.02 ± 2.5/-0.1 ± 0.25D, far UCVA: 0.34 ± 0.2/0.90 ± 0.1, near UCVA: 0.43 ± 0.4/1.0 ± 0.02, Add: 1.4 ± 1.2/0.2 ± 0.6D, far BCVA: 0.90 ± 0.2/0.95 ± 0.1, and near BCVA: 0.99 ± 0.04/1.0 ± 0.0. Mean Q satisfaction points (0-10): far VA: 7.5 ± 2, near VA: 8.1 ± 2.3, intermediate VA 8.1 ± 1.7. Mean questionnaire difficulty points (0-4) results were: far VA 1.3 ± 1.5, near VA 1.5 ± 1.5, halos 1.5 ± 1.6, and 94% would repeat their choice. Near vision and night driving difficulties scored higher for myopes with greater preoperative SE (R2=0.5; p=0.05 and R2=0.7; p=0.02, respectively). Conclusion: Multifocal intraocular lens implantation, in patients with previous refractive surgery, significantly improved mean near and far UCVA, and addition. Satisfaction was high and post LASIK SE correlated significantly with near vision and night driving difficulty in myopic patients.

Influence of LASEK on Schiøtz, Goldmann and dynamic contour Tonometry.

Our purpose was to assess the effect of LASEK surgery on ocular rigidity and to compare its effect on intraocular pressure (IOP) readings with Goldmann applanation tonometry (GAT), Schiøtz indentation tonometry (ST) and dynamic contour tonometry (DCT). Prospective, observational, single-masked cohort study. One eye per patient from 31 consecutive subjects who underwent LASEK refractive surgery to correct myopia, as well as from 108 non-operated myopic patients, were included. IOP was measured using GAT, DCT, and ST. The coefficient of ocular rigidity (Ko) was obtained from the regression line of the three readings obtained with each weight of the ST. Linear multiple regression analysis was performed with dummy variables to assess the effect of age, central corneal thickness (CCT), and previous refractive surgery on IOP values. Age, CCT, and LASEK surgery explained 23% of the IOP readings with GAT, 11% with DCT, and had no significant influence on ST readings. The IOP readings obtained with GAT and DCT, but not with ST, were significantly different between LASEK and control groups. Significant differences in Ko were observed between LASEK (0.014mmHg/μL ±0.007) and control groups (0.021mmHg/μL ±0.013) (P=0.001). Ko values were not related with age or CCT, in either LASEK or control groups. ST readings seems to be less affected by LASEK surgery than the other tonometers evaluated. There is a difference in the ocular rigidity between the control and the LASEK eyes that it is not correlated with CCT, so it seems that ST can detect changes in the biomechanical behavior of the LASEK operated corneas.

Comparison of visual outcomes after bilateral implantation of a diffractive trifocal intraocular lens and blended implantation of an extended depth of focus intraocular lens with a diffractive bifocal intraocular lens.

PurposeThe purpose of this study was to compare the visual outcomes and subjective visual quality between bilateral implantation of a diffractive trifocal intraocular lens, Alcon Acrysof IQ® PanOptix® TNFT00 (group A), and blended implantation of an extended depth of focus lens, J&J Tecnis Symfony® ZXR00 with a diffractive bifocal intraocular lens, J&J Vision Tecnis® ZMB00 (group B).MethodsThis prospective, nonrandomized, consecutive, comparative study included the assessment of 40 eyes in 20 patients implanted with multifocal intraocular lens. Exclusion criteria were existence of any corneal, retina, or optic nerve disease, previous eye surgery, illiteracy, previous refractive surgery, high axial myopia, expected postoperative corneal astigmatism of >1.00 cylindrical diopter (D), and intraoperative or postoperative complications. Binocular visual acuity was tested in all cases. Ophthalmological evaluation included the measurement of uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), uncorrected near visual acuity (UNVA), and uncorrected intermediate visual acuity (UIVA), with the analysis of contrast sensitivity (CS), and visual defocus curve.ResultsPostoperative UDVA was 0.01 and −0.096 logMAR (p<0.01) in groups A and B, respectively; postoperative CDVA was −0.07 and −0.16 logMAR (p<0.01) in groups A and B, respectively; UIVA was 0.14 and 0.20 logMAR (p<0.01) in groups A and B, respectively; UNVA was −0.03 and 0.11 logMAR (p<0.01) in groups A and B, respectively. Under photopic conditions group B had better CS at low frequencies with and without glare.ConclusionBoth groups promoted good quality of vision for long, intermediate, and short distances. Group B exhibited a better performance for very short distances and for intermediate and long distances ≥−1.50 D of vergence. Group A exhibited a better performance for UIVA at 60 cm and for UNVA at 40 cm.

Descemet Membrane Endothelial Keratoplasty in Eyes With Previous Laser Refractive Surgery: Outcomes and Complications.

To evaluate the refractive predictability and efficacy of Descemet membrane endothelial keratoplasty (DMEK) for patients with previous laser refractive surgery. We retrospectively reviewed our cohort of endothelial keratoplasty surgical cases. We identified 21 eyes that underwent laser-assisted in situ keratomileusis (n = 17) or photorefractive keratectomy (n = 4) and were treated with DMEK for endothelial failure. Patients were analyzed preoperatively and at 6 months postoperatively for changes in visual acuity, refraction, and corneal topography. Six months after surgery, eyes significantly improved to a mean best-corrected visual acuity of 20/23 (P < 0.001). Mean astigmatism amplitude changed from 1.13 ± 0.96 preoperatively to 0.92 ± 0.51 diopters postoperatively (P = 0.28). However, shifts in the axis of corneal astigmatism ranged from 1 to 70 degrees, with 6 eyes (30%) showing an axis shift of more than 30 degrees. Spherical equivalents in nontriple procedures remained unchanged (n = 16; P = 0.69) at 6 months. DMEK and DMEK triple procedures are predictable in patients with previous refractive surgery achieving good visual results. However, refraction after the use of toric intraocular lenses may be unpredictable because of the variability in changes of the magnitude and axis of corneal astigmatism; we recommend extreme caution in the use of the toric intraocular lens in this group of patients and proper counseling for possible individual postoperative residual astigmatism.

Multifocal intraocular lens implantation after previous corneal refractive laser surgery for myopia

To describe the refraction and visual acuity outcomes of multifocal intraocular lens (IOL) implantation in patients with previous corneal refractive laser surgery for myopia. Academic Medical Center, University of Amsterdam, Amsterdam, and Retina Total Eye Care, Driebergen, the Netherlands. Retrospective cohort study. The 3-month results after implantation of a multifocal IOL (Acrysof Restor) in patients who had corneal refractive laser surgery for myopia were analyzed. The primary outcome measures were corrected distance visual acuity, uncorrected distance visual acuity (UDVA), and refraction. The secondary outcome measures were number of laser enhancements, corneal irregularity, pre-laser magnitude of myopia, and posterior capsule opacification (PCO) rate. Seventy-seven eyes of 43 patients were included. Twenty-nine eyes had lens extraction because of cataract, and 48 eyes had a refractive lens exchange. The mean postoperative UDVA was 0.14 logarithm of minimum angle of resolution ± 0.22 (SD). The mean postoperative spherical equivalent was -0.38±0.78 diopter (D). Fifty-seven percent of eyes were within ±0.50 D of emmetropia, and 86% were within ±1.0 D. Sixteen eyes (20.8%) had laser enhancement because of residual refraction. Fourteen eyes (18.2%) had a neodymium:YAG laser capsulotomy because of PCO. Eyes with pre-laser myopia greater than 6.0 D had a less predictable outcome than eyes with pre-laser myopia less than 6.0 D (P=.026). Multifocal IOL implantation after corneal refractive laser surgery for myopia resulted in good visual acuity and refraction. Results were less predictable with myopia greater than 6.0 D.

U.S. Multicenter Clinical Trial of Corneal Collagen Crosslinking for Treatment of Corneal Ectasia after Refractive Surgery

To evaluate the safety and efficacy of corneal collagen crosslinking (CXL) for the treatment of corneal ectasia after laser refractive surgery. Prospective, randomized, multicenter, controlled clinical trial. One hundred seventy-nine subjects with corneal ectasia after previous refractive surgery. The treatment group underwent standard CXL, and the sham control group received riboflavin alone without removal of the epithelium. The primary efficacy criterion was the change over 1 year of topography-derived maximum keratometry (K), comparing treatment with control groups. Secondary outcomes evaluated were corrected distance visual acuity (CDVA), uncorrected distance visual acuity (UDVA), manifest refraction spherical equivalent, endothelial cell count, and adverse events. In the crosslinking treatment group, the maximum K value decreased by 0.7 diopters (D) from baseline to 1 year, whereas there was continued progression in the control group (1.3 D difference between treatment and control, P < 0.0001). In the treatment group, the maximum K value decreased by 2.0 D or more in 14 eyes (18%) and increased by 2.0 D or more in 3 eyes (4%). The CDVA improved by an average of 5.0 logarithm of the minimum angle of resolution (logMAR) letters. Twenty-three eyes (32%) gained and 3 eyes (4%) lost 10 or more logMAR letters. The UDVA improved 4.5 logMAR letters. Corneal haze was the most frequently reported crosslinking-related adverse finding. Corneal collagen crosslinking was effective in improving the maximum K value, CDVA, and UDVA in eyes with corneal ectasia 1 year after treatment, with an excellent safety profile. CXL is the first approved procedure to diminish progression of this ectatic corneal process.