Monocular Uncorrected Visual Acuity Research Articles

Measures and variability with age of low contrast acuity and near stereoacuity in children

ABSTRACT Clinical relevance Low contrast acuity (LCA) and near stereoacuity (NS) testing are integral to the comprehensive assessment of sensory visual function in children. However, routine ophthalmological evaluations seldom take these measures into consideration. Additionally, there is limited literature regarding the normative values of these parameters in children. Background This study investigated LCA and NS measures and their variability in children with normal visual acuity. The aim was to provide a benchmark for distinguishing normal measures from abnormal ones. Methods A prospective observational study was conducted in primary and secondary schools across North India. The participants numbered 240 children, aged between 3 and 15 years. They were split into 12 smaller groups of 20 participants in each age group. Only participants with normal monocular uncorrected visual acuity, no refractive error, normal birth history, and no systemic ailments, were recruited. All the participants underwent a complete ophthalmic examination and non-cycloplegic retinoscopy. LCA was measured, using the low contrast Lea number chart at three metres. NS was measured using the Randot® stereo test at 40 cm. Results The percentages of males and females, were found to be 55%, and 45%, respectively (p = 0.093). The mean NS was found to be 38.7 ± 11.5 arcsecs in the 3-9-year age group, and 26.7 ± 5.6 arcsecs in the 9-15-year age group (p-value <0.001). The mean NS showed an increasing trend up to 9 years of age. The mean LCA was 64.4 ± 20.1 in the age group of 3–8 years, and 76.38 ± 11.39 in the age group of 8–15 years (p-value <0.001). Considerable variability was noted in the LCA in the younger age group (p-value = 0.000). Conclusions LCA and NS mature gradually during childhood. LCA stabilises after the age of 8, while NS stabilises after the age of 9.

Refractive Outcomes Following Trifocal Intraocular Lens Implantation in Post-Myopic LASIK and PRK Eyes.

PurposeTo assess refractive outcomes of a trifocal intraocular lens (IOL) in post-myopic laser refractive surgery eyes.MethodsThis was a retrospective chart review of 35 eyes (21 patients), with history of laser refractive surgery, who were implanted with a trifocal IOL. Surgeon’s standard procedure included femtosecond laser (FLACS), digital registration, and intraoperative aberrometry (IA). The primary outcome measure was absolute prediction error. Secondary measures were refractive outcomes, postoperative residual astigmatism (PRA), monocular uncorrected visual acuity at distance (UDVA; 4m), intermediate (UIVA; 60cm), and near (UNVA; 40cm), and monocular best-corrected visual acuity at distance (BCVA; 4m).ResultsAt 3 months postoperatively, 71% and 68% of eyes had absolute prediction error 0.5 D or less with IA and preoperative planning respectively, which was not statistically significant (p > 0.05). The PRA was 0.5 D or less in 91% of eyes with IA and 56% of eyes with preoperative planning. The PRA differences between IA and preoperative planning were statistically significant (p < 0.002). The percentage of eyes 20/20 or better for monocular UCVA, BCVA, UIVA, and UNVA was 29%, 77%, 78%, and 66%, respectively. Absolute prediction error 0.5 D or less was significantly higher in post-LASIK eyes versus post-PRK eyes (p < 0.003), at 85% and 56% of eyes, respectively.ConclusionImplantation with a trifocal IOL can provide acceptable refractive and visual outcomes with minimal residual astigmatism in post-myopic LASIK and PRK eyes.

Visual Performance of a Novel Optical Design of a New Multifocal Intraocular Lens.

To evaluate the optical performance and quality of vision of a novel optical design of a new trifocal intraocular lens (IOL) using a proprietary modified algorithm. In this prospective, non-randomized, single-armed, single-center, open-label study, a total of 20 patients (40 eyes) who were candidates for multifocal lens implantation were recruited for implantation with the multifocal Intensity SL IOL (Hanita Lenses). Evaluation performed at 1 and 7 to 10 days and 1 and 3 months after implantation included corrected and uncorrected distance visual acuities at far, intermediate (80 cm), and near (40 cm). Monocular and binocular visual acuities, defocus curves, and contrast sensitivity were measured and questionnaires for grading subjective visual quality, satisfaction, and visual function were provided. Three months postoperatively, monocular uncorrected visual acuity for distance, intermediate, and near averaged 0.03 ± 0.11, 0.09 ± 0.09, and -0.22 ± 0.09 logMAR, respectively (Snellen 20/21.4, 20/24.6, and 20/12). Corrected monocular visual acuity for distance, intermediate, and near averaged -0.07 ± 0.06, 0.03 ± 0.09, and -0.25 ± 0.07 logMAR (20/17, 20/21.4, and 20/11.2), respectively. Binocular corrected visual acuity for distance, intermediate, and near was -0.1 ± 0.06, -0.02 ± 0.09, and -0.28 ± 0.04 logMAR (20/15.8, 20/19, and 20/10.5), respectively. Contrast sensitivity was similar to the normal population in photopic and mesopic conditions. Defocus curves showed that this IOL provided visual acuity of 20/28.9 or better between a defocus of +1.00 and -3.50 diopters. The Visual Function Index-14 questionnaire showed that patients reported high satisfaction. Patients specifically noted good quality of vision at near and intermediate distances. The Intensity SL IOL can provide good quality distance, intermediate, and particularly strong near vision after cataract surgery and independence from spectacles with good patient satisfaction. [J Refract Surg. 2022;38(3):150-157.].

Long-Term Evaluation of Visual Outcomes and Patient Satisfaction after Binocular Implantation of a Bioanalogic Lens.

Purpose Long-term evaluation of the visual refractive outcomes and the quality of life after implantation of the WIOL-CF (Medicem, Czech Republic) in both eyes. Design retrospective, nonrandomized noncomparative case series. Methods 50 eyes of 25 patients, including 11 women (44%) and 14 men (56%). The age range of the patients was 38 to 77 years (mean age 55.48 ± 10.97 years). All patients underwent bilateral implantation of the WIOL-CF. Exclusion criteria were previous ocular surgeries except for cataract surgery and refractive lens exchange, irregular corneal astigmatism of >1.0 diopter, and ocular pathologies or corneal abnormalities. Postoperative examinations were performed at 14 days and 3, 6, 12 months of surgery; the last follow-up was between 24 and 36 months after the procedure. All exams included manifest refraction, monocular uncorrected visual acuity (UCVA) and distance-corrected visual acuity (DCVA) in 5 m (Snellen), monocular uncorrected visual acuity in 70 cm and 40 cm (Jeager) and binocular UCVA, DCVA in 5 m, 70 cm, and 40 cm, binocular contrast sensitivity (CS) under photopic conditions, binocular defocus curves, high-order aberrations, quality-of-vision VF-14 questionnaire, and spectacle independence. Results Significant improvement in monocular visual acuity at all distances was demonstrated; the mean postoperative spherical equivalent was 0.32 ± 0.45D. The postoperative means of binocular distance UCVA and BCVA were also improved (p < .001) and so were the mean uncorrected intermediate VA (2.053 ± 1.268) and near uncorrected VA (2.737 ± 1.447). There was a significant improvement in contrast sensitivity at all spatial frequencies and higher-order aberration, compared to preoperative results. Conclusions The evaluation of a WIOL-CF showed good distance, intermediate, and near visual acuity. Contrast sensitivity increased after surgery in all spatial frequencies. Patient satisfaction was high despite some optical phenomena. The rate of postoperative spectacle independence also turned out high. Financial Disclosure. No author has a financial or proprietary interest in any material or method mentioned.

Standard Results and Contrast Sensitivity Reestablishment after Implantation of a Trifocal Intraocular Lens

ABSTRACT Purpose/Aim To assess, following the standards, the results of safety, efficacy and predictability for a trifocal intraocular lens and to evaluate contrast sensitivity and visual acuity defocus curve. Materials and Methods Fifty subjects operated on cataract surgery or refractive lens exchange with a trifocal intraocular lens have been recruited for the study. The monocular uncorrected visual acuity (VA) at far, intermediate (67 cm) and near (40 cm) distances in addition to corrected VA at far and near distances was evaluated at 1 week, 1 month and 3 months after surgery. Postoperative refraction, binocular contrast sensitivity function (CSF) and binocular defocus curves were also collected at the 3-month follow-up visit. Results Mean uncorrected VA was 0.10, 0.07 and 0.05 logMAR at far, intermediate and near distances. Corrected distance VA at far and near distances was 0.04 and 0.02 logMAR. Ninety percent and 100% achieved a spherical equivalent in ±0.50 D and ±1.00 D, respectively. CSF was above normal range for 12 and 18 cycles per degree (cpd) in all the conditions, inside the normal range in 1.5, 3 and 6 cpd and only decreased below normal range for 1.5 and 3 cpd in mesopic vision without glare. Conclusions The procedure achieved a safety, efficacy and predictability similar to those reported by previous studies. The CSF was generally enhanced after the procedure in comparison to those reported in non-operated subjects above 60 years old. Previous studies might underestimate the effective distance of the intermediate and near foci.

Features of Femtosecond Correction of High Myopia through Small Access

Aim. To modify the calculated parameters of the lenticle extraction refractive surgery through a small access (SMILE), evaluate its safety and clinical efficacy in correcting high myopia.Materials and methods. 34 patients (68 eyes) underwent surgery by a modified SMILE technology under local anesthesia. In all cases, the patients had a high degree of myopia, in 37 % in combination with astigmatism.Uncorrected visual acuity before surgery averaged 0.05 ± 0.11, best corrected visual acuity of 0.94 ± 0.1, the pre-operative spherical refraction component was –7.23 ± 0.75, the cylindrical component was –0.48 ± 0.59.During the operation, to obtain the maximum possible refraction result using the proposed method, the standard operation parameters were changed: the corneal flap thickness was reduced to 100 μm, the neural optical layer by 5 μm, the diameter of the optical zone depended on the residual cornea thickness, which should exceed 280–290 μm. Corneal access was increased by 15–20 degrees.Results. The next day after surgery, monocular uncorrected visual acuity in distance in 73 % of patients was 0.8 or higher, and in 41 % of cases it was equal to or exceeded 1.0. The spherical equivalent on the first day after surgery had a slight hypermetropic shift, which was completely leveled by the year of follow-up. During the surgical intervention and in the postoperative period, no complications were noted.Conclusion. Using the proposed algorithm for calculating the refractive effect of the operation SMILE with a high degree of myopia allows obtaining a high refractive effect and avoiding possible complications.

Bilateral Implantation of a Single-Piece Bifocal Diffractive Intraocular Lens in Presbyopic Patients: A Prospective Case Series.

To report visual outcomes and quality after bilateral implantation of a single-piece diffractive multifocal intraocular lens (MIOL) with a bifocal design. Prospective, observational case series. All presbyopic subjects were implanted with the ZMB00 MIOL (Abbott Medical Optics) at the Hong Kong Sanatorium and Hospital. We evaluated the distance, intermediate, and near visual acuity (VA) under photopic and mesopic conditions; contrast sensitivity with and without glare under photopic and mesopic conditions; quality of vision; and rate of spectacle independence. A total of 36 subjects were included. No intraoperative complications developed. At the 6-month visit, the mean (± standard deviation) monocular uncorrected VAs at distance, intermediate, and near were 0.01 ± 0.12, 0.26 ± 0.17, and 0.09 ± 0.08, respectively. The respective mean binocular uncorrected VAs were -0.05 ± 0.09, 0.12 ± 0.13, and 0.04 ± 0.06. No eyes lost any corrected distance VA. The binocular contrast sensitivity was significantly better without glare than with glare under photopic and mesopic conditions (P < 0.05 for all spatial frequencies under both conditions). A total of 21 (58%) and 21 subjects (58%) reported halo and glare, respectively. Thirty subjects (83%) reported complete spectacle independence. Bilateral implantation of the bifocal MIOL in presbyopic patients with or without cataract was safe and resulted in satisfactory vision and a high rate of spectacle independence. Halos and glare were common.

МОДИФИКАЦИЯ ТЕХНОЛОГИИ SMILE В КОРРЕКЦИИ АМЕТРОПИЙ

Purpose: To evaluate the clinical efficacy and safety of modified SMILE surgery for mild myopia. Methods: The study involved 68patients (135eyes), operated by SMILE methods for mild myopia. The first group included patients operated by standard technology with a 15μm thickness of neural optical lenticular layer, the second group – patients, operated by a modified SMILE technology monolayer with thickness of 30μm. A comprehensive ophthalmology examination was performed before the surgery and after the surgical treatment – on the following day, in one month and in 12 months. Results: In all patients of both groups the monocular uncorrected visual acuity after the operation after the period of one day, one month, and a year did not differ and made 0.88±0.15, 0.92±0.1 and 0.95±0.08 respectively, for the second group – 0.87±0.18, 0.92±0.15 and 0.96±0.10 (p≥0.05). Follow-up in the early and late postoperative period convincingly demonstrated that visual acuity, refraction, spatial sensitivity, corneal hysteresis indices and even a subjective assessment of visual quality have no statistically significant differences among patients in both groups. During the operation and late postoperative period the complications were not noted. Conclusion: the study found that the modified technology provides high visual acuity, while minimally changing the biomechanical properties of the cornea. Thus, a modified SMILE operation is highly predictable and safe method in correction of slight degree myopia

Comparison of Intracorneal Inlay for Presbyopia Correction: Hydrogel and Small-Aperture Inlays with a Six- Months Follow-Up

Purpose: To study the safety and efficacy of corneal reshaping and small-aperture inlays and compare the clinical results. Methods: From February 2014 to November 2014, 22 corneal reshaping inlays were inserted at Asan Medical Center and from October 2012 to March 2013, 26 small-aperture inlay surgeries were performed: 6 eyes at Asan Medical Center and 20 eyes at Samsung Medical Center. The preoperative and postoperative parameters were reviewed retrospectively and included monocular uncorrected distance visual acuity (UDVA; log MAR), uncorrected near visual acuity (UNVA; log MAR), refraction and corneal curvature based on automated refractor keratometry, reading distance and patient satisfaction. Results: In the hydrogel inlay group, preoperative mean monocular UNVA was 0.83 ± 0.05 and monocular UDVA 0.07 ± 0.03. At 6 months, mean monocular UNVA was 0.23 ± 0.05 and UDVA 0.05 ± 0.02. The most preferred mean reading distance in the hydrogel inlay group was 39.38 ± 3.18 cm. In the small-aperture inlay group, preoperative mean monocular UNVA was 0.4 ± 0.06 and monocular uncorrected visual acuity 0.27 ± 0.04. At 6 months, mean monocular UNVA was 0.11 ± 0.02 and UDVA 0.09 ± 0.05 and the most preferred mean reading distance was 44.23 ± 5.17 cm. Although 85% of patients in the corneal reshaping inlay group were satisfied or very satisfied, only 20% of patients in the small-aperture inlay group were satisfied. Conclusions: Both inlays are considered good options for correcting presbyopia. However, postoperative satisfaction score was higher and less glare symptoms were reported in the hydrogel inlay group. J Korean Ophthalmol Soc 2015;56(12):1840-1847

Contrast sensitivity after refractive lens exchange with a multifocal diffractive aspheric intraocular lens

To evaluate distance and near contrast sensitivity (CS) under photopic and mesopic conditions before and after refractive lens exchange (RLE) and implantation of the aspheric AcrySofReSTOR (SN6AD3 model) intraocular lens (IOL). Seventy-four eyes of 37 patients after RLE underwent bilateral implantation with the aspheric AcrySof ReSTOR IOL. The patient sample was divided into myopic and hyperopic groups. Monocular uncorrected visual acuity at distance and near (UCVA and UCNVA, respectively) and monocular best corrected visual acuity at distance and near (BCVA and BCNVA, respectively) were measured before and 6 months postoperatively. Monocular CS function was measured at three different luminance levels (85, 5 and 2.5 cd/m²) before and after RLE. Post-implantation results at 6 months were compared with those found before surgery. Our results revealed that patients in both groups obtained good UCVA and BCVA after RLE at distance and near vision in relation to pre-surgery values. No statistically significant differences were found between the values of CS pre and post-RLE at distance and near, at any lighting condition and spatial frequency (p>0.002). Refractive lens exchange with aspheric AcrySof ReSTOR IOL in myopic and hyperopic population provided good visual function and yield good distance and near CS under photopic and mesopic conditions.

Refractive lens exchange with a multifocal diffractive aspheric intraocular lens

To evaluate the safety, efficacy and predictability after refractive lens exchange with multifocal diffractive aspheric intraocular lens implantation. Sixty eyes of 30 patients underwent bilateral implantation with AcrySof(®) ReSTOR(®) SN6AD3 intraocular lens with +4.00 D near addition. Patients were divided into myopic and hyperopic groups. Monocular best corrected visual acuity at distance and near and monocular uncorrected visual acuity at distance and near were measured before and 6 months postoperatively. After surgery, uncorrected visual acuity was 0.08 ± 0.15 and 0.11 ± 0.14 logMAR for the myopic and hyperopic groups, respectively (50% and 46.67% of patients had an uncorrected visual acuity of 20/20 or better in the myopic and hyperopic groups, respectively). The safety and efficacy indexes were 1.05 and 0.88 for the myopic and 1.01 and 0.86 for the hyperopic groups at distance vision. Within the myopic group, 20 eyes remained unchanged after the surgery, and 3 gained >2 lines of best corrected visual acuity. For the hyperopic group, 2 eyes lost 2 lines of best corrected visual acuity, 21 did not change, and 3 eyes gained 2 lines. At near vision, the safety and efficacy indexes were 1.23 and 1.17 for the myopic and 1.16 and 1.13 for the hyperopic groups. Best corrected near visual acuity improved after surgery in both groups (from 0.10 logMAR to 0.01 logMAR in the myopic group, and from 0.10 logMAR to 0.04 logMAR in the hyperopic group). The ReSTOR(®) SN6AD3 intraocular lens in refractive lens exchange demonstrated good safety, efficacy, and predictability in correcting high ametropia and presbyopia.

Comparison of the Visian ICL and Verisyse Phakic Intraocular Lenses for Myopia From 6.00 to 20.00 Diopters

To compare visual and refractive outcomes between the Visian Implantable Collamer Lens (ICL) and Verisyse phakic intraocular lens. Comparative interventional case series for myopia between 6.00 and 20.00 diopters (D). Thirty consecutive eyes of 16 patients had a Visian ICL implanted and 31 consecutive eyes of 19 patients had the Verisyse lens implanted. Outcomes measured at 3 months postoperatively included uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), and refractive predictability as well as adverse events. Preoperatively, the groups were no different in regard to age (P=.72) and spherical equivalent refraction (P=.38). Postoperative UCVA of 20/20 or better and 20/25 or better in the Visian ICL group was 67% and 96%, respectively, compared to 63% and 79%, respectively, in the Verisyse lens group (P=.10). Binocular UCVA of 20/20 or better and 20/25 or better in the Visian ICL group was 92% and 100%, respectively, and in the Verisyse group, 70% and 80%, respectively (P=.007). One and two lines gain of postoperative BSCVA in the Visian ICL group was 40% and 10%, respectively, which was statistically significantly better than the Verisyse group of 16% and 6%, respectively (P=.025). Postoperative deviation from target refraction was 0.038+/-0.39 D in the Visian ICL group and -0.38+/-0.89 D in the Verisyse lens group (P=.018). Monocular UCVA was similar for both groups, whereas binocular UCVA was better in the Visian ICL group. The Visian ICL group had more accurate refractive outcomes than the Verisyse lens group.

Subjektive und objektive Ergebnisse nach Implantation der apodisiert diffraktiven AcrySof ReSTOR

Our purpose in this study was to assess the postoperative subjective and objective results after implantation of the Acrysof ReSTOR lens and to evaluate the advantages and limitations of the apodized diffractive optic design of this new multifocal intraocular lens (MIOL). Phakoemulsification and implantation of an Acrysof ReSTOR was performed in 55 eyes of 32 patients. All patients were examined after a mean period of 7.9+/-1.9 months. The accuracy of lens calculation was evaluated for the Haigis, Holladay I, and SRK-T formulas. Uncorrected and corrected visual acuity for distance and for intermediate and near vision were assessed, as was stereoacuity. In addition, contrast sensitivity was tested under photopic and mesopic conditions, with and without glare. The patients were asked about dysphotic phenomena such as halos, glare or flare, and night vision using a standardized evaluation. The degree to which patients were able to manage without spectacles after the surgery was also documented. The median monocular uncorrected visual acuity (UCVA) for distance was 20/25 (LogMAR 0.05) while the binocular UCVA was 20/20 (LogMAR 0). The monocular uncorrected acuity for near vision was 20/25 (LogMAR 0.1), the binocular near visual acuitiy was 20/20 (LogMAR 0), while the intermediate monocular visual acuity was 20/50 (LogMAR 0.4) and the binocular, 20/32 (LogMAR 0.2). Contrast sensitivity was within the normal range. Dysphotic phenomena were noted by 66% of patients but were so slight as not to cause any problem at all in 59%. For close work and distance vision 84% of all patients needed no correcting glasses, while 78% did not need to use glasses for intermediate vision. The Acrysof ReSTOR provides excellent uncorrected visual acuity for distance and near vision and the level of patient satisfaction achieved with it is good.

Overnight Orthokeratology

To determine the refractive and corneal topographic recovery after the use of reverse-geometry contact lenses for overnight orthokeratology. Both eyes of 15 subjects were fitted with reverse-geometry contact lenses that were worn by the subjects for 1 month. Uncorrected visual acuity, refractive correction (sphere and spherical equivalent), corneal curvature, and corneal thickness were measured during this time and for 2 weeks after discontinuation of lens wear. Ten subjects completed the investigation. Uncorrected visual acuity, refractive correction, and corneal curvature had changed significantly (P = 0.01) after 1 month of lens wear. By the end of 1 month, central corneal thickness was significantly thinner than the baseline value (P = 0.01), but it recovered fully after one night of no lens wear. Recovery of corneal curvature was complete 1 week after lens wear was discontinued. Refractive correction and binocular uncorrected visual acuity recovered fully after 2 weeks. Monocular uncorrected visual acuity remained significantly (P = 0.01) different from baseline acuity 2 weeks after lens discontinuation. Full effect of overnight orthokeratology in low myopes is achieved within 1 week of initiating use of reverse-geometry lenses. Recovery after short-term use of reverse-geometry lenses is rapid for corneal thickness and corneal curvature. Refractive correction and binocular uncorrected visual acuity recovered fully after 2 weeks. Monocular uncorrected visual acuity was the slowest to recover and had not achieved full recovery after 2 weeks.