Target Refraction Research Articles

Deciphering the enigma of astigmatism in cataract surgery

With about 87% of patients with cataracts having astigmatism, management of astigmatism in cataract surgery not only yields an improved unaided visual acuity and image quality but also higher patient satisfaction. The video will give a step-wise guide to cataract surgeons to manage astigmatism with cataracts. To hit the bull's eye as far as target refraction is concerned, it is necessary to understand the benefits and limitations of currently available cutting-edge technology and formulae and apply them to the cataract surgery practice. The purpose of the video is to make sure that we have no surprises in our Toric intraocular lens (IOL) planning. After a brief introduction to available modalities for the treatment of astigmatism, a step-wise approach to diagnostics is discussed, which will include the role of corneal topography and aberrometers and their application to planning Toric IOLs. Appropriate planning, implementation, and execution in form of preoperative and intraoperative pearls of using Toric IOLs are shown in the video. This will be followed by troubleshooting and case-based discussions and future perspectives including the possible role of corneal biomechanics. What this video adds new is the importance of topography, interpretation of Belin‒Ambrosio display map and the equivalent keratometry reading (EKR) map, aberrometry, and higher order aberration (HOA) analysis and role of biomechanics in Toric IOL planning. Video also highlights the importance of posterior corneal astigmatism and accurate axis marking. With a case-based approach and relevant examples, we are trying to decipher the enigma of astigmatism by giving a step-wise approach for the same. https://youtu.be/5VuEY_6NdQA.

Ten commandments for biometry in tricky situations.

Recently, the number of litigations on cataract surgeons has increased. Because of the increasing ambitions of surgeons and demands for a spectacle-free life, the incidence of unhappy patients is at an all-time high. To an ophthalmologist, the fruits of a good surgery are dependent largely on their skills. However, more importantly, the roots of good results of a surgery are laid by a perfect IOL (intraocular lens) power calculation. Inaccurate biometry is one of the major reasons for unhappy patients, especially in some challenging scenarios. To hit the bull's eye, as far as target refraction is concerned, it is necessary to understand the benefits and limitations of currently available cutting-edge technology and formulae and apply them to the cataract surgery practice. The aim of the video is to familiarize modern-day ophthalmologists to these situations to achieve a perfect IOL power calculation. Using a step-by-step approach, we decoded biometry in special scenarios like poor cornea, ocular surface disorders, dry eyes, toric IOL calculation, cases with posterior corneal astigmatism, irregular corneas like keratoconus, pellucid marginal degeneration, post Lasik ectasia and penetrating keratoplasty. In this video we tried to address the solution to these special conditions and how to attain target refraction in such cases. A few more issues are addressed like biometry post retina surgery, very dense cataract where it is difficult to obtain axial length, and cases with extreme axial lengths. In this case-based approach, with relevant example, we tried to provide solutions for biometry in tricky scenarios like poor cornea, biometry post refractive surgery, dense cataracts, and cataract post retinal surgery. On following these commandments, not only will the litigations stop but our patients will be happier as well. https://youtu.be/dNXP2nDYUZo.

Effectiveness of Laser Refractive Surgery to Address Anisometropic Amblyogenic Refractive Error in Children: A Report by the American Academy of Ophthalmology

To review the published literature assessing the safety and effectiveness of laser refractive surgery to treat anisometropic amblyogenic refractive error in children aged ≤ 18 years. A literature search of the PubMed database was conducted in October 2021 with no date limitations and restricted to publications in English. The search yielded 137 articles, 69 of which were reviewed in full text. Eleven articles met the criteria for inclusion and were assigned a level of evidence rating. The 11 included articles were all level III evidence and consisted of 1 case-control study and 10 case series. Six studies used laser-assisted in situ keratomileusis (LASIK), 1 used photorefractive keratectomy (PRK), 1 used refractive lenticule extraction/small incision lenticule extraction, and the rest used a combination of LASIK, PRK, laser epithelial keratomileusis (LASEK), or refractive lenticule extraction/small incision lenticule extraction. Five studies enrolled patients with anisometropic myopia, 2 studies enrolled patients with anisometropic hyperopia, and the remainder were mixed. Although all studies demonstrated an improvement in best-corrected visual acuity (BCVA), the magnitude of improvement varied widely. As study parameters varied, a successful outcome was defined as residual refractive error of 1 diopter (D) or less of the target refraction because this was the most commonly used metric. Successful outcomes ranged between 38% and 87%, with a mean follow-up ranging from 4 months to 7 years. Despite this wide range, all studies demonstrated an improvement in the magnitude of anisometropia. Regression in refractive error occurred more frequently and to a greater degree in myopic eyes and eyes with longer follow-up, and in younger patients. Although one study reported 2 free flaps, most studies reported no serious adverse events. The most common complications were corneal haze and striae. Findings from included studies suggest that laser refractive surgery may address amblyogenic refractive error in children and that it appears to decrease anisometropia. However, the evidence for improvement in amblyopia is unclear and long-term safety data are lacking. Long-term data and well-designed clinical studies that use newer refractive technologies in standardized patient populations would help address the role of refractive surgery in children and its potential impact on amblyopia.

Preliminary Examination Before Cataract Surgery

To plan and execute a successful and safe cataract surgery one must conduct a structured, goal- and patient-oriented examination. The medical history provides crucial information regarding the planning of the anesthetic procedure, lens selection and possible intraoperative complications. Visual acuity and refraction measurements are essential for both documentation and discussion of the selected target refraction. Multifocal lenses have various contraindications to which attention must be paid during slit lamp examination and other imaging diagnostics. These include epithelial basement membrane dystrophy, Fuchs' endothelial dystrophy, zonular weakness, and progressive retinal diseases such as progressive AMD. Tomography reveals corneal irregularities as well as possible refractive laser treatments that have been performed previously. Lens calculation is complicated in these cases. Additionally, an endothelial cell count, aberrometry to rule out higher order aberrations, pupillometry and an analysis of the tear film can provide further information. The patient must be informed verbally about the severity of the procedure and the risks relevant for him with sufficient distance to the surgery.

This issue of ACTA

This issue of ACTA

In Vivo Intraocular Lens Thickness Measurement and Power Estimation Using Optical Coherence Tomography.

PurposeTo estimate the power of an implanted intraocular lens (IOL) by measuring IOL thickness using anterior segment optical coherence tomography (AS-OCT) and to assess the repeatability of measurements.MethodsNinety-seven eyes were studied one month after uneventful phacoemulsification within the bag Acrysof SA60AT IOL implantation (range +11 to +35). All eyes had postoperative refraction of 0.5 D of target refraction. AS-OCT was used to measure the central thickness of the IOL. Correlation between labelled IOL power and central IOL thickness as well as the measure of repeatability, for example, intraclass correlation coefficient (ICC), were evaluated. IOL thicknesses were also calculated using a formula and compared with AS-OCT derived measurements.Results IOL thickness correlated significantly with labelled IOL power (R2 = 0.985, P 0.001). The regression equation (IOL Power = [0.04 IOL thickness in micron] – 7.56) indicates 25 microns of central IOL thickness change per 1D power change. Over the studied range, IOL power could be estimated with a precision of 0.85 0.02 D (95% confidence interval: 0.83–0.94D). ICC for repeated measurements was 0.999. There was a significant correlation between calculated and measured (AS-OCT) IOL thickness (R2 = 0.984, P 0.001).ConclusionCentral IOL thickness measurements with the AS-OCT are highly repeatable and closely correlated with the labelled IOL power, which can predict the IOL power with 0.85 D from the actual power. This method can be helpful in cases of postoperative IOL surprise.

Anterior Chamber Iris-Fixated Phakic Intraocular Lens Implantation for Treatment of High Anisometropia in Children: Long-term Results.

To evaluate the long-term efficacy of anterior chamber iris-fixated phakic intraocular lens (PIOL) implantation in the treatment of high myopic (> -9.00 diopters [D]) or hyperopic (> +6.00 D) anisometropia in children with intolerance to spectacles or contact lenses. A total of 58 children with anisometropic myopia (range: -9.25 to -18.50 diopters [D]) and 13 children with anisometropic hyperopia (range: +6.00 to +8.50 D) underwent unilateral iris-claw PIOL implantation from 2008 to 2018. The mean age was 6.7 years. The mean follow-up was 38.5 months. Target refraction was emmetropia. The cycloplegic refraction (mean spherical equivalent) improved from -12.47 D (range: -9.25 to -18.50 D) to -0.73 D (range: +0.75 to -1.50 D) in myopic eyes and reduced from +7.15 D (range: +6.00 to +8.50 D) to +0.94 D (range: -0.50 to + 1.75 D) in hyperopic eyes. Eighty-four percent of eyes were corrected to within ±1.00 D of emmetropia. The mean uncorrected distance visual acuity (UDVA) improved from 1.74 ± 0.36 to 0.45 ± 0.28 logarithm of the minimum angle of resolution (logMAR) (P = .0014). The mean corrected distance visual acuity (CDVA) changed from 0.68 ± 0.32 to 0.27 ± 0.15 logMAR (P = .02179). The safety index was 2.18 and the efficacy index was 1.51. The mean preoperative endothelial cell count of 2,874.7 cells/mm2 changed to 2,685.3 cells/mm2 at 2 to 6 years postoperatively. Binocular vision quality was improved in 55 patients. No patient had serious complications or lost any Snellen lines of CDVA. Iris-fixated PIOL implantation is an effective and safe method in the treatment of high anisome-tropic myopia and hyperopia and amblyopia in pediatric patients who are noncompliant with spectacles or contact lenses. [J Pediatr Ophthalmol Strabismus. 2023;60(3):203-209.].

Clinical and functional indicators of the eyes in children with pseudophakia and their mothers

AIM: To analyze clinicofunctional and echobiometric indicators of the eyes in children with target refraction, pseudofacial myopia, and their mothers.
 MATERIAL AND METHODS: In the eye department of the clinic of the Tashkent Pediatric Medical Institute, a correlation analysis of optical and echobiometric indicators was conducted in 30 children (30 eyes) with artifakia and their mothers (60 eyes). Visiometry, keratorefractometry, and ultrasound examination (A/B scan of the eyeball) were conducted. Children were examined 1214 months after CC extraction with intraocular lens (IOL) implantation.
 RESULTS: A strong direct correlation was determined between the optical power of IOLs in children and their mothers who were theoretically planned for IOL implantation of IOLs in the group that has achieved target refraction. This may indicate the possibility that the child has the same optical power as the mother and the optical power of IOLs in a child is the same as that in adults. No correlation was found between the optical power of the IOL in the eyes of children with pseudophakic myopia and maternal artificial lenses theoretically planned for implantation.
 CONCLUSION: The direct strong correlations between the optical power of the IOL of children and the lenses of their mothers in the group with the target refraction achieved by this age make it possible to use the optical power of maternal lenses as a guideline when calculating the power of the IOL implanted in children to achieve the target refraction. The lack of correlation between the refractive powers of the IOL in children with pseudophakic myopia and the lenses of mothers may indicate that the SRK II formula with age-related hypocorrection is not adapted to calculate the IOL power in children at risk of excessive refractive enhancement after surgery.

Ocular parameter changes after phacoemulsification in pseudoexfoliative eyes: case-control study.

To assess changes of angle morphometric parameters, anterior chamber depth (ACD), intraocular pressure (IOP), and endothelial cell density (ECD) after uneventful phacoemulsification in eyes with pseudoexfoliation syndrome (PEX) compared with those in eyes without PEX and to evaluate the effect of these changes on effective lens position and postoperative refraction. Papageorgiou Hospital, Thessaloniki, Greece. Prospective case-control study. Angle opening distance, trabecular-iris space area, and scleral spur angle width were measured using anterior segment optical coherence tomography. ACD was assessed using IOLMaster and ECD using specular microscopy. All parameters were evaluated at baseline and 2 months postoperatively. 42 patients (42 eyes) with PEX and 39 patients (39 eyes) without PEX who underwent uneventful phacoemulsification were enrolled. All angle parameters and ACD increased significantly after phacoemulsification in both groups ( P < .001), with no statistically significant difference between them ( P > .05). Percentile change in ACD was greater in PEX eyes ( P = .017). Regarding the mean refractive prediction error, no statistically significant differences were found between the study groups ( P = .68). A statistically significant trend toward hyperopic shift was noted in the PEX group ( P = .039). IOP and ECD diminished postoperatively in both groups, with no statistically significant difference between the study groups ( P = .09 and P = .22, respectively). PEX, compared with non-PEX eyes, demonstrated a greater anterior chamber deepening and a hyperopic shift after phacoemulsification. These could be related to the zonular laxity in eyes with PEX and imply that PEX eyes may require a modified target refraction to achieve the desired refractive outcome.

Visual Outcomes of an Enhanced UV Protected Light Adjustable Lens Using a Novel Co-Managed, Open-Access Methodology.

PurposeTo report on the safety and visual acuity (VA) outcomes using a co-managed, open-access methodology with a second-generation (ActivShieldTM) Light Adjustable Lens (LAL 2.0).Patients and MethodsThis retrospective observational case series of consecutive patients implanted with the LAL 2.0 choosing an emmetropic target in at least one eye were included in the study. All patients were co-managed with light treatments occurring at an open-access facility. Exclusion criteria included pathology of the macula and/or cornea with reduced best corrected visual acuity (BCVA). The primary outcome measures were uncorrected distance visual acuity (UDVA), spherical equivalent (SE), and residual cylinder for emmetropic goal eyes at the final 3- to 9-month postoperative visit.ResultsThirty-three patients (62 eyes) were included in the study and implanted with the LAL 2.0. Thirty-three (53.2%) eyes had previous corneal refractive treatment(s) with 22 (66.7%) having no original historical refractive records available. Thirty-six (58.1%) total eyes and 20 (32.3%) postrefractive eyes had an emmetropic refractive target. Of all the emmetropic goal eyes, 35 (97.2%) saw 20/20 or better and 36 (100%) were within ±0.50 D SE of plano and had a mean cylinder of −0.15 ± 0.26 D. Of the postrefractive emmetropic goal eyes, 19 (95%) saw 20/20 or better, 20 (100%) were within ±0.50 D SE of plano and had a mean cylinder of −0.17 ± 0.28 D.ConclusionA co-managed, open-access methodology using the LAL 2.0 was safe and efficacious even in challenging postrefractive clinical scenarios.

Simultaneous Presbyopia and Astigmatism Correction with a Novel Trifocal Toric Intraocular Lens-A One-Year Follow-Up.

The current investigation evaluates the efficiency of the trifocal toric Liberty 677MTY intraocular lens (IOL) in correcting preoperative corneal astigmatism in cataract patients demanding spectacle independence. The retrospective evaluation included 28 eyes of 15 patients with preoperative corneal astigmatism of at least 1.0 Dioptre (D). All patients were followed up for one year postoperatively. Residual refractive errors and visual acuities at multiple distances were measured. Binocular visual acuity and contrast sensitivity defocus curves were plotted. Visual functions and patient satisfaction were assessed. The efficiency of astigmatism correction was determined using the vector analysis method. The mean spherical equivalent refraction (SEQ) improved from 2.72 ± 1.62 D to 0.10 ± 0.48 D. The cylindric refraction decreased from 1.18 ± 0.45 D to 0.16 ± 0.31 D. Vector analysis proved efficient astigmatism correction with a centroid of 0.10 ± 0.34 D at 161°. Ninety-two percent of eyes resulted within 0.5 D from the target refraction. Visual acuities were 0.1 logMAR or better from +1.0 to −3.5 D defocus values. Visual tasks could be performed without major difficulties. Our patients were highly satisfied. Refractive and visual outcomes with the investigated presbyopia-correcting toric IOL are predictable and the lens provides excellent trifocal vision.

Calculation of Intraocular Lens Optical Power with Enhanced Depth of Focus

Relevance. The new Increased Depth of Focus (EDOF) Intraocular Lens (IOL) technology is designed to improve the correction of visual acuity at a medium distance without compromising distance vision correction and provides a restoration of visual acuity in the distance and at an average distance, but at the same time a lower frequency of side optical phenomena and better contrast sensitivity compared to other multifocal IOLs (MIOL). Regardless of the technology used and the type of lens, the result of surgery and patient satisfaction depend on the optimization of the calculation of the optical strength of the IOL. To date, there is no consensus in the available literature on the choice of a formula for calculating the optical power of known EDOF IOLs.Aim. Retrospective analysis of the accuracy of 7 formulas for optical power calculation of a new extended depth of focus intraocular lens.Methods. The retrospective study included 34 patients (62 eyes) with implantation of a new EDOF Tecnis Symfony IOL ZXR00. The mean age of the patients was 61.9 ± 9.4 (39–87) years. IOL optical power range was +5.0 to +30.0 D, target refraction was –0.25 to 0.25 D. The average follow-up period for the patients was 12.3 ± 1.8 months. The SRK/T, Barrett Universal II, Haigis, Hoffer Q, Holladay 2, Olsen, and Kane formulas were retrospectively analyzed for effectiveness using appropriate constants. Each formula was optimized for the study group of patients to achieve an average refractive error as close to zero as possible. For each formula, the mean error (ME), mean absolute error (MAE), standard deviation (SD), median absolute error (MedAE), maximum absolute error (MaxAE), and percentage of eyes within the error range of 0.25, 0.5, 1.0, and 2.0 D were calculated.Results. The optimized constants were LF = 2.21, a0 = 1.43, a1 = 0.39, a2 = 0.12, personalized ACD=5.68, ACD (Hoffer Q / Holladay 2) = 5.68/5.66, A-constant (SRK/T / Kane) = 119.5/119.4. For the SRK/T, Barrett Universal II, Kane and Haigis formulas the lowest MAE is shown. Application of the Hoffer Q and Holladay 2 formulas are associated with the highest MAE. The Barrett Universal II, SRK/T, Kane, and Haigis formulas were characterized by the highest percentage of reaching refraction of ±0.25 D (64, 62, 59, and 53, respectively). For all of the formulas examined, the frequency of reaching refraction of ±1.00 D was greater than 90% and within ±2.00 D greater than 97%.Conclusion. This study was the first to retrospectively compare seven formulas for calculating the optical power of a new intraocular lens with an enhanced depth of focus. The SRK/T, Barrett Universal II, Haigis, and Kane formulas are recommended for calculating the optical power of the indicated IOL in clinical practice.

IOL Power Calculation Features after Radial Keratotomy

IOL power calculation after keratorefractive surgery is an important applied aspect of cataract surgery. The probability of refractive error is especially high when calculating in patients with a history of radial keratotomy. There is no unified approach to the tactics and methodology of calculation for this category of patients at the moment. The studies were conducted in a group of 17 patients (26 eyes) with a history of RK. The Haigis formula, which does not use keratometry to predict ELP, was chosen as the main one for the calculation. IOL calculation and biometrics were carried out on the IOL-Master, but corrected TCP IOL (Ray Traced) data obtained on the Galilei keratotomograph were manually entered into the optional keratometry fields. Thу Burrett True-K and Hoffer Q were used as verification formulas, the calculation was also carried out on IOL-Master, using corrected Galilei data. In all cases, postoperative refraction close to emmetropic was obtained. The spherical component of refraction ranged from +0.5 to -1.0 D, cylindrical — from 0.0 to 4.0 D, according to autorefractometry. Visual acuity without correction ranged from 0.4 to 1.0. Uncorrected visual acuity of 0.8 and higher was obtained in 65.38% of cases. The calculation algorithm implemented by us using the Haigis formula in combination with the use of individually adjusted keratometric TCP IOL data (Ray Traced, Galilei), allowed us to significantly improve the accuracy of IOL power calculating in patients with a history of RK and achieve target refraction even in cases of complex and irregular corneal topography.

Discussing Questions of Laser Refractive Surgery in Hyperopia: Literature Review and Clinical Experience

Relevance. Modern keratorefractive surgery is a high-tech field of ophthalmology aimed at solving various problems of correcting a wide range of ametropias.Objective: to formulate recommendations for refractive surgeons when planning the correction of hypermetropic refraction using modern keratorefractive surgery.Materials and methods. An analysis of 20 literature sources and a retrospective analysis of outpatient records of 188 patients with hypermetropia who underwent surgery were carried out.Results. The analysis of the literature and our own clinical study allows us to recommend focusing on the final keratometry after keratorefractive surgery, which should not exceed 48 diopters. Among the analyzed charts of patients in compliance with these criteria, the accuracy of hitting the target refraction in the range of ± 1 D was 98.9 %, the regression did not exceed 0.5 D from that obtained 1 month after surgery in 96.8 %, and the loss of 1 line of BCVA was 3.7 % of cases. Among patients with achieved keratometry above 48 diopters, the loss of line 1 BCVA was 13.8 %, line 2 — 2.7 %.Conclusion. Thus, the tactics of correction of hypermetropia by CRC methods require an integrated approach to the assessment of visual functions, drug preparation for surgery, careful implementation of the surgical stages of the intervention, and rational postoperative pharmacological support.

Outcomes of combined phacoemulsification/intraocular lens implantation and silicon oil removal.

To evaluate the outcomes and complications of simultaneous silicon oil removal (SOR) and phacoemulsification and intra ocular lens implantation. In this retrospective non-comparative case series, the visual, refractive and anatomical outcomes of patients who underwent combined phacoemulsification/silicone oil removal (5700 centistokes) surgery between 2017 and 2019 in a single center were evaluated. Forty-four eyes of 44 patients (eighteen males) were included. The mean age of the patients was 51.45 ± 11.59 years. The primary pathology was tractional retinal detachment (TRD) secondary to diabetic retinopathy in 36 eyes and rhegmatogenous retinal detachment (RRD) in 8 eyes. The median time period between silicone oil tamponade and removal was 9 months. There was no statistically significant difference between best corrected visual acuity (-0.14 ± 0.69 LogMAR, p= 0.19) and intraocular pressure (p= 0.26) before and after the surgery. Mean post-operative spherical equivalent (SE) at last visit was 0.36 ± 1.64 which was different from the target refraction (- 0.5D). After cataract/SOR surgery, one eye (2.3%) developed retinal re-detachment in RRD patient. Vitreous hemorrhage occurred in nine eyes (20.5%) which all had TRD as the primary pathology. Combined phacoemulsification, silicone oil and IOL implantation removal surgery seems to be a safe and useful procedure with high success rate and acceptable visual, refractive and anatomical outcomes.

Femtosecond Laser-Assisted Cataract Surgery: A Report by the American Academy of Ophthalmology

To evaluate refractive outcomes, safety, and cost-effectiveness of femtosecond laser-assisted cataract surgery (FLACS) compared with phacoemulsification cataract surgery (PCS). A PubMed search of FLACS was conducted in August 2020. A total of 727 abstracts were reviewed and 33 were selected for full-text review. Twelve articles met inclusion criteria and were included in this assessment. The panel methodologist assigned a level of evidence rating of I to all 12 studies. No significant differences were found in mean uncorrected distance visual acuity, best-corrected distance visual acuity, or the percentage of eyes within ± 0.5 and ± 1 diopter of intended refractive target between FLACS and PCS. Intraoperative and postoperative complication rates were similar between the 2 groups, and most studies showed no difference in endothelial cell loss between FLACS and PCS at various time points between 1 and 6 months. In large randomized controlled studies in the United Kingdom and France, FLACS was less cost-effective than PCS. Both FLACS and PCS have similar excellent safety and refractive outcomes. At this time, one technique is not superior to the other, but economic analyses performed in some populations have shown that FLACS is less cost-effective.

Intraoperative aberrometry compared to preoperative Barrett True-K formula for intraocular lens power selection in eyes with prior refractive surgery.

To compare the predictive refractive accuracy of intraoperative aberrometry (ORA) to the preoperative Barrett True-K formula in the calculation of intraocular lens (IOL) power in eyes with prior refractive surgery undergoing cataract surgery at the Loma Linda University Eye Institute, Loma Linda, California, USA. We conducted a retrospective chart review of patients with a history of post-myopic or hyperopic LASIK/PRK who underwent uncomplicated cataract surgery between October 2016 and March 2020. Pre-operative measurements were performed utilizing the Barrett True-K formula. Intraoperative aberrometry (ORA) was used for aphakic refraction and IOL power calculation during surgery. Predictive refractive accuracy of the two methods was compared based on the difference between achieved and intended target spherical equivalent. A total of 97 eyes (69 patients) were included in the study. Of these, 81 eyes (83.5%) had previous myopic LASIK/PRK and 16 eyes (16.5%) had previous hyperopic LASIK/PRK. Median (MedAE)/mean (MAE) absolute prediction errors for preoperative as compared to intraoperative methods were 0.49 D/0.58 D compared to 0.42 D/0.51 D, respectively (P = 0.001/0.002). Over all, ORA led to a statistically significant lower median and mean absolute error compared to the Barrett True-K formula in post-refractive eyes. Percentage of eyes within ± 1.00 D of intended target refraction as predicted by the preoperative versus the intraoperative method was 82.3% and 89.6%, respectively (P = 0.04). Although ORA led to a statistically significant lower median absolute error compared to the Barrett True-K formula, the two methods are clinically comparable in predictive refractive accuracy in patients with prior refractive surgery.

Visual and Refractive Outcomes Following Laser Blended Vision With Non-linear Aspheric Micro-anisometropia (PRESBYOND) in Myopic and Hyperopic Patients.

To report 6-month visual and refractive outcomes following PRESBYOND Laser Blended Vision (Carl Zeiss Meditec) treatment using non-linear aspheric micro-anisometropia laser in situ keratomileusis (LASIK) for the correction of myopic and hyperopic presbyopia. A retrospective, non-comparative study of 139 consecutive patients with a mean age of 53.13 ± 5.84 years (range: 42 to 70 years) treated with LASIK-induced micro-anisometropia using the MEL 90 excimer laser and VisuMax femtosecond laser (both Carl Zeiss Meditec). The target refraction was plano for distance eyes (dominant eye) and between -0.50 and -1.50 diopters (D) for near eyes. Patients were observed for 6 months. A total of 278 eyes (78 myopic and 200 hyperopic) from 139 patients completed the study. Mean preoperative spherical equivalent (SE) was -3.40 ± 1.83 D (range: -0.50 to -8.25 D) for myopic eyes and +1.61 ± 0.98 D (range: -1.25 to +4.63 D) for hyperopic eyes. Mean postoperative SE refraction of distance eyes was +0.20 ± 0.35 D (range: -0.38 to +1.00 D) and -0.14 ± 0.42 D (range: -1.38 to +0.88 D) for myopic and hyperopic eyes, respectively. Mean postoperative SE refraction of near eyes was -0.90 ± 0.44 D (range: -0.13 to -2.25 D) and -1.21 ± 0.48 D (range: -0.13 to -2.25 D) for myopic and hyperopic eyes, respectively. Mean binocular uncorrected near visual acuity was 0.70 ± 0.28 logMAR (range: 0.32 to 1.00 logMAR) and 0.79 ± 0.27 logMAR (range: 0.25 to 1.00 logMAR) for myopic and hyperopic eyes, respectively. Mean binocular uncorrected distance visual acuity was 1.19 ± 0.18 logMAR (range: 0.63 to 1.25 logMAR) and 1.14 ± 0.26 logMAR (range: 0.40 to 1.25 logMAR) for myopic and hyperopic eyes, respectively. Stereoacuity was better than 100 seconds of arc in 79% of myopic eyes and 85% of hyperopic eyes and all vision quality scores were greater than 90 of 100. No eyes lost two or more lines. The non-linear aspheric micro-anisometropia protocol resulted in safe and effective visual outcomes in patients with both myopic and hyperopic presbyopia. [J Refract Surg. 2022;38(5):288-297.].

Combined accelerated collagen crosslinking and sub-Bowman’s keratomileusis in high myopic eyes: a comparison between total ultraviolet energy dose

ABSTRACT Aim To compare the safety, efficacy, and predictability outcomes of combined sub-Bowman’s keratomileusis (thin flap laser in situ keratomileusis [LASIK]) and accelerated crosslinking (CXL) using two different irradiation durations. Methods A retrospective comparative study of patients with percent tissue altered ≥35%, undergoing simultaneous CXL during sub-Bowman’s keratomileusis were recruited. Following riboflavin application, they underwent ultraviolet-A (UVA) irradiation (18 mW/cm2) for either 2 min (total energy 2.16 J/cm2) or 3 min (total energy 3.24 J/cm2). Visual and refractive outcomes were compared between follow-up visits during the first year postoperatively. Demarcation line and endothelial cell count were evaluated, respectively, at 1 and 3 months postoperatively. Results The baseline characteristics were similar between the 40 eyes/patients treated using the 2-min protocol and the 33 eyes/patients treated with the 3-min protocol (p ≥ .114). Uncorrected distance visual acuity and corrected distance visual acuity were significantly better for eyes treated with the shorter irradiation protocol on Day 1 (p ≤ .030) and Month 1 (p ≤ .040) postoperatively; these differences diminished by Month 3 (p ≥ .070). Likewise, the efficacy index was higher during the first postoperative week for the 2-min protocol (p ≤ .043). At 1 year, the proportion of eye attaining within 0.5 D of target refraction was 80.0% and 84.8% for the 2-min and 3-min protocols, respectively (p = .590). The corresponding corneal stromal demarcation line depth and endothelial cell density changes were comparable between the two groups (p = .311 and 0.899, respectively). Conclusions A comparable volume of crosslinked corneal tissue can be achieved by using a shorter UVA irradiation duration. Additional duration of UVA irradiation could lead to delay in visual rehabilitation after simultaneous sub-Bowman’s keratomileusis and CXL.

Patient Satisfaction and Visual Performance in Patients with Ocular Pathology after Bilateral Implantation of a New Extended Depth of Focus Intraocular Lens.

Aim To evaluate visual results and patient-perceived outcomes in patients with ocular pathologies implanted with a new extended depth-of-focus intraocular lens (IOL). Methods Patients with ocular pathology undergoing cataract surgery and bilaterally implanted with Vivity® IOLs were evaluated three months after surgery. The control group included patients with no ocular pathologies. Binocular defocus curves, corrected and uncorrected mono- and binocular distance visual acuity (DVA), and binocular contrast sensitivity were measured. Patients completed the Catquest-9SF questionnaire and reported on dysphotopsia and their need for spectacle-correction. Results Twenty-five patients were included in each group. Monocular uncorrected DVA was better in the control group (−0.01 ± 0.07) compared with the study group (0.03 ± 0.08), p=0.027. There were no other statistically significant differences in DVA, with an uncorrected binocular acuity of −0.06 ± 0.06 for the control group and −0.05 ± 0.06 for the study group. Binocular defocus curves were similar for both groups and there were no differences in contrast sensitivity values. Pooling the refractive results, 96% of eyes were within ±0.50 D of target refraction. Seventy percent of patients in the control group reported no halos, compared with 40% in the study group, p=0.047. In both groups, 40% of patients reported being completely spectacle-independent, with the other 60% requiring glasses for near vision always or often. All patients reported being fairly or very satisfied with their vision. Conclusion Initial results of visual function after Vivity implantation in patients with ocular pathologies are encouraging, with high patient satisfaction and few difficulties for daily activities.