Peripheral Vision in Patients Following Intraocular Lens Implantation: A Systematic Review and Meta-Analysis.

PURPOSE: To update the literature on peripheral optics and vision following intraocular lens (IOLs) implantation. METHODS: We investigated how current IOLs influence peripheral visual function, peripheral optical quality, and visual perception and performance, in patients following cataract surgery. Peripheral vision is described as vision outside the central foveal region of the eye (beyond 4-5° of eccentricity). We systematically searched PubMed, Cochrane Central Register of Controlled Trials, Embase, and gray literature for relevant references. Randomized controlled trials and observational studies were eligible for inclusion. Finally, 47 studies with a total of 5963 participants were eligible for this review, of which 15 were included in the meta-analysis. RESULTS: Regarding visual fields, the meta-analysis showed that the pooled estimate of mean deviation (MD) measured with perimetry tests (standard automated perimetry [SAP], short-wavelength automated perimetry [SWAP], and frequency doubling technology [FDT]) appears to be lower than the mean of healthy age-matched controls, regardless of IOL design. Results for pooled estimate show that localized defects (pattern standard deviation [PSD]) were higher than those in the healthy age-matched controls for FDT. We also collected evidence demonstrating that pseudophakia increases peripheral astigmatism and a myopic shift from 20° onward, leading to decreased peripheral image quality compared with that in phakic eyes. Patient-reported outcomes on peripheral vision showed a pooled score estimate of 95.19, indicating high satisfaction, and for the Steps & Stairs questions, a pooled score estimate at 0.23, indicating no to little difficulty seeing steps and stairs. CONCLUSIONS: Peripheral image quality is degraded in eyes after cataract surgery. Nevertheless, whether this degradation leads to impaired visual function in the periphery requires further investigation.

Visual Performance at All Distances and Patient Satisfaction With a New Aspheric Inverted Meniscus Intraocular Lens.

PURPOSE: To evaluate visual performance, spectacle independence, and quality of vision of new intraocular lenses (IOLs) for presbyopia correction with an aspheric inverted meniscus optical design (ArtIOLs; Voptica SL) in patients undergoing bilateral cataract surgery. METHODS: In this prospective study, 60 eyes from 30 patients implanted bilaterally with Art40 and Art70 IOLs were included. These new IOLs were designed with an inverted meniscus shape to improve the peripheral performance and with aspheric surfaces to induce different amounts of negative spherical aberration in each IOL model. Distance-corrected and uncorrected through-focus visual acuities and contrast sensitivity were measured 1 to 3 months after surgery. Twenty-eight patients answered Patient Reported Spectacle Independence (PRSIQ) and Quality of Vision (QoV) questionnaires. RESULTS: Mean monocular (Art40 and Art70) and binocular (Art40/70) corrected distance visual acuities (CDVA) were zero logMAR (20/20). Binocular uncorrected distance visual acuity (UDVA) at far, intermediate (66 cm), and near (40 cm) distances was 0.00 ± 0.01, 0.01 ± 0.03, and 0.09 ± 0.09 logMAR, respectively. Spectacle independence was achieved by 24 (85.7%) patients for far and intermediate vision and 20 patients (71.4%) for near vision. The number of patients never reporting experiencing glare, halos, and starbursts was 28, 27, and 26 (100%, 96.4%, and 92.9%), respectively. CONCLUSIONS: The binocular combination of two ArtIOLs models (Art40 and Art70) significantly extended the depth of focus up to at least 40 cm. This combination resulted in a full range of vision with a high level of spectacle independence and without the compromise of halos or dysphotopsias. [J Refract Surg. 2023;39(9):582-588.].

Peripheral Refraction and Contrast Detection Sensitivity in Pseudophakic Patients Implanted With a New Meniscus Intraocular Lens.

PURPOSE: To evaluate peripheral refraction and contrast detection sensitivity in pseudophakic patients implanted with a new type of inverted meniscus intraocular lens (IOL) (Art25; Voptica SL) that was designed to provide better peripheral optics. METHODS: One month after cataract surgery, in 87 eyes implanted with the Art25 IOL, peripheral contrast detection sensitivity was measured psychophysically at 40° visual angle, both horizontally and vertically, and compared with a control group of 51 eyes implanted with standard biconvex IOLs. Thirty-one eyes with the Art25 IOL and 28 eyes from the control group were randomly selected to also measure peripheral refraction using a scanning Hartmann-Shack wavefront sensor along 80° in the horizontal meridian. RESULTS: Most patients achieved emmetropia and good visual acuity, and no significant adverse events were observed after cataract surgery with Art25 IOLs. Peripheral contrast detection sensitivity was significantly better (P < .01) in the group with the Art25 IOL in both directions (7.78 ± 3.24 vs 5.74 ± 2.60 vertical, 10.98 ± 5.09 vs 7.47 ± 3.96 horizontal), which was in agreement with the optical quality improvement in the periphery due to a reduction of defocus (1.97 and 1.21 diopters [D] at 40° temporal and nasal sides) and astigmatism (1.17 and 0.37 D at 40° temporal and nasal sides) that was statistically significant (P < .01) from 20° of eccentricity. CONCLUSIONS: Patients implanted with a new inverted meniscus IOL present a reduced amount of peripheral defocus and astigmatism compared to patients implanted with standard biconvex IOLs. This improvement in optical quality leads to better contrast detection sensitivity measured at 40° of eccentricity. [J Refract Surg. 2022;38(4):229-234.].

Spherical Aberration Customization to Extend the Depth of Focus With a Clinical Adaptive Optics Visual Simulator.

PURPOSE: To evaluate the use of the VAO adaptive optics visual simulator (Voptica SL, Murcia, Spain) for customization of spherical aberration to increase depth of focus. METHODS: Through-focus visual acuity with both high- and low-contrast letters from +1.00 to -3.00 diopters (D) was measured in 17 dilated eyes with three different induced amounts of spherical aberration for a 4.5-mm pupil diameter: control (0 µm), -0.15 µm, and -0.30 µm. RESULTS: The defocus curves followed the same behavior with both values of contrast, but the visual acuity was 0.2 logMAR lower with low contrast. The mean values of high-contrast logMAR visual acuity at far, intermediate (67 cm), and near (40 cm) were -0.10, 0.11, and 0.37 for control, 0.04, 0.00, and 0.15 for -0.15 µm, and 0.23, 0.00, and 0.06 for -0.30 µm conditions. The 95% confidence interval ranged from ±0.14 to ±0.45 logMAR and the middle 50% of the distribution was approximately 0.2 logMAR. CONCLUSIONS: Negative values of spherical aberration extend the depth of focus in different ways depending on each patient. The VAO is a new instrument that allows the visual customization of spherical aberration to enhance depth of focus. [J Refract Surg. 2020;36(4):223-229.].

Effect of Crystalline Lens Aberrations on Adaptive Optics Simulation of Intraocular Lenses.

PURPOSE: To evaluate the impact of the lens aberrations on the adaptive optics visual simulation of pseudophakic intraocular lens (IOL) profiles. METHODS: In 20 right phakic eyes, lens higher order aberrations (HOAs) were calculated as the whole eye minus the corneal aberrations. Visual simulation using low and high contrast corrected distance visual acuity (CDVA) testing was carried out with the VAO instrument (Voptica, SL, Murcia, Spain), considering three optical conditions of the lens: removing HOA (no lens-HOA), removing spherical aberration (no lens-SA), and with lens HOA (natural condition). In addition, a through-focus visual simulation of a trifocal diffractive IOL profile with high contrast CDVA was also measured in two conditions: no lens-HOA and natural condition. Three different pupil sizes (3, 4.5, and 6 mm) were tested for all conditions. RESULTS: There were no significant intersubject differences between the three optical conditions and in the IOL simulation for all pupil sizes (P > .05). For 4.5- and 6-mm pupils, mean VA values of the no-lens SA and no lens-HOA conditions were similar and slightly worse than those of the natural condition. Individual differences between the no lens-HOA condition and the other two optical conditions, estimated as 95% limits of agreement, were acceptable for 3-mm pupil but worse as pupil diameter increased. CONCLUSIONS: The effect of lens aberrations on visual simulation is imperceptible for a small pupil diameter of 3 mm. Although the increment of pupil size increases the probability of patients with significant visual impact of lens HOAs, the mean intersubject VA differences are negligible. [J Refract Surg. 2019;35(2):126-131.].

Assessment of subjective refraction with a clinical adaptive optics visual simulator.

PURPOSE: To clinically validate an adaptive optics visual simulator (VAO) that measures subjective refraction and visual acuity. SETTING: Optics Laboratory, University of Murcia, Murcia, Spain. DESIGN: Prospective case series. METHODS: Using the adaptive optics visual simulator, 2 examiners measured the subjective refraction and visual acuity in healthy eyes of volunteers; 1 examiner also used a trial frame as a gold standard. The interexaminer reproducibility and agreement with the gold standard were estimated using the following statistical parameters: limits of agreement from Bland-Altman analysis, significance between differences (P value), and intraclass correlation coefficient (ICC). RESULTS: Seventy-six eyes of 38 volunteers were measured. Interexaminer reproducibility for subjective refraction was excellent (ICC ≥0.96; P > .05), with low 95% confidence interval (CI) values for the power vectors M (spherical equivalent of the given refractive error), J0 (Jackson cross-cylinder, axes at 180 degrees and 90 degrees), and J45 (Jackson cross-cylinder, axes at 45 degrees and 135 degrees) (±0.51 diopter [D], ±0.14 D, and ±0.14 D, respectively). No significant differences in subjective refraction and visual acuity were found between the visual simulator and gold standard (P > .05), with 95% CIs for M, J0, and J45 (subjective refraction) of ±0.67 D, ±0.14 D, and ±0.16 D, respectively, and a ±0.10 logarithm of the minimum angle of resolution (visual acuity). CONCLUSION: Subjective refraction results using the adaptive optics visual simulator agreed with those of the gold standard and can be used as the baseline for visual simulation of any optical corneal profile or intraocular lens design for refractive surgery patients.

Micrometric Control of the Optics of the Human Eye: Environment or Genes?

Purpose: The human eye has typically more optical aberrations than conventional artificial optical systems. While the lower order modes (defocus and astigmatism) are well studied, our purpose is to explore the influence of genes versus the environment on the higher order aberrations of the optical components of the eye. Methods: We have performed a classical twin study in a sample from the Region of Murcia (Spain). Optical aberrations using a Hartmann-Shack sensor (AOnEye Voptica SL, Murcia, Spain) and corneal aberrations (using corneal topography data) were measured in 138 eyes corresponding to 69 twins; 36 monozygotic (MZ) and 33 dizygotic (DZ) pairs (age 55 years, SD 7 years). Intraclass correlation coefficients (ICCs) were used to estimate how strongly aberrations of twins resemble each other, and genetic models were fitted to quantify heritability in the selected phenotypes. Results: Genes had a significant influence in the variance of most of the higher order aberration terms (heritability from 40% to 70%). This genetic influence was observed similarly in both cornea and complete eye aberrations. Additionally, the compensation factor of spherical aberration in the eye (i.e., how much corneal spherical aberration was compensated by internal spherical aberration) was found under genetic influence (heritability of 68%). Conclusions: There is a significant genetic contribution to the variance of aberrations of the eye, not only at macroscopic levels, as in myopia or astigmatism, but also at microscopic levels, where a few micrometers changes in surface topography can produce a large difference in the value of the optical aberrations.

Optical Measurement of Straylight in Eyes With Cataract.

PURPOSE: To measure straylight in a cohort of patients with cataract using a novel optical instrument and to correlate optical straylight values with clinical grade of cataracts and psychophysical straylight values. METHODS: Measurements were performed on 53 eyes of 44 patients with cataract admitted to the ophthalmology service of the university hospital in Murcia, Spain, and 9 young volunteers with no known ophthalmic pathology. Lens opacities were classified according to the Lens Opacities Classification System Ill (LOCS III) under slit-lamp examination. Intraocular straylight was additionally assessed psychophysically using the C-Quant straylight meter (Oculus Optikgeräte GmbH, Wetzlar, Germany). RESULTS: Optical measurements of the logarithm of the straylight parameter ranged from 1.01 to 2.01 (mean: 1.43 ± 0.244) in patients with cataract and 0.80 to 1.08 (mean: 0.92 ± 0.104) in healthy young volunteers. Straylight differed by a statistically significant amount among different LOCS III groups (P < .05). Moreover, the optically measured straylight parameter was positively correlated to the psychophysically estimated value (r = 0.803, P < .05). CONCLUSIONS: A new compact optical instrument suitable for clinical measurements of straylight in the human eye has been developed. Optically measured straylight values were highly correlated to those that were obtained psychophysically. Optical measurement of straylight can be used for the objective classification of cataract opacities based on their optical impact. [J Refract Surg. 2016;32(12):846-850.].

The accommodative ciliary muscle function is preserved in older humans.

Presbyopia, the loss of the eye's accommodation capability, affects all humans aged above 45-50 years old. The two main reasons for this to happen are a hardening of the crystalline lens and a reduction of the ciliary muscle functionality with age. While there seems to be at least some partial accommodating functionality of the ciliary muscle at early presbyopic ages, it is not yet clear whether the muscle is still active at more advanced ages. Previous techniques used to visualize the accommodation mechanism of the ciliary muscle are complicated to apply in the older subjects, as they typically require fixation stability during long measurement times and/or to have an ultrasound probe directly in contact with the eye. Instead, we used our own developed method based on high-speed recording of lens wobbling to study the ciliary muscle activity in a small group of pseudophakic subjects (around 80 years old). There was a significant activity of the muscle, clearly able to contract under binocular stimulation of accommodation. This supports a purely lenticular-based theory of presbyopia and it might stimulate the search for new solutions to presbyopia by making use of the remaining contraction force still presented in the aging eye.

Environmental and Genetic Factors Explain Differences in Intraocular Scattering.

PURPOSE: To study the relative impact of genetic and environmental factors on the variability of intraocular scattering within a classical twin study. METHODS: A total of 64 twin pairs, 32 monozygotic (MZ) (mean age: 54.9 ± 6.3 years) and 32 dizygotic (DZ) (mean age: 56.4 ± 7.0 years), were measured after a complete ophthalmologic exam had been performed to exclude all ocular pathologies that increase intraocular scatter as cataracts. Intraocular scattering was evaluated by using two different techniques based on a straylight parameter log(S) estimation: a compact optical instrument based in the principle of optical integration and a psychophysical measurement. Intraclass correlation coefficients (ICC) were used as descriptive statistics of twin resemblance, and genetic models were fitted to estimate heritability. RESULTS: No statistically significant difference was found for MZ and DZ groups for age (P = 0.203), best-corrected visual acuity (P = 0.626), cataract gradation (P = 0.701), sex (P = 0.941), optical log(S) (P = 0.386), or psychophysical log(S) (P = 0.568), with only a minor difference in equivalent sphere (P = 0.008). Intraclass correlation coefficients between siblings were similar for scatter parameters: 0.676 in MZ and 0.471 in DZ twins for optical log(S); 0.533 in MZ twins and 0.475 in DZ twins for psychophysical log(S). For equivalent sphere, ICCs were 0.767 in MZ and 0.228 in DZ twins. Conservative estimates of heritability for the measured scattering parameters were 0.39 and 0.20, respectively. CONCLUSIONS: Correlations of intraocular scatter (straylight) parameters in the groups of identical and nonidentical twins were similar. Heritability estimates were of limited magnitude, suggesting that genetic and environmental factors determine the variance of ocular straylight in healthy middle-aged adults.