A systematic review of pseudophakic monovision for presbyopia correction

IRIS® Registry (Intelligent Research In Sight) Analysis of the Incidence of Monovision in Cataract Patients with Bilateral Monofocal Intraocular Lens Implantation

Purpose

To determine the incidence of pseudophakic monovision among patients bilaterally implanted with monofocal intraocular lenses (IOLs) and to characterize the distribution of myopic offsets achieved.

Patients and Methods

This retrospective database study included data on patients receiving care from ophthalmologists who contributed to the Academy IRIS® (Intelligent Research In Sight) Registry. Anonymized data were collected, including patient age, ethnicity, procedure data (CPT code, date, laterality), and postoperative manifest refractive spherical equivalent (MRSE) in both eyes implanted with monofocal or monofocal toric IOLs. No data regarding IOL manufacturer, model, or power were collected. One primary outcome measure was the percentage of patients achieving monovision (defined as emmetropia within ±0.25 diopters [D] in one eye and a myopic offset of ≥0.50 D in the fellow eye) among all patients receiving bilateral monofocal IOLs at the time of cataract surgery between January 1, 2016, and September 1, 2019, with at least 90 days of follow-up. Other primary outcomes included the distribution and frequency of myopic offsets (anisometropia) between eyes.

Results

Of the 16,765 people receiving bilateral monofocal IOLs within the study period, 4796 (28.6%) achieved emmetropia in at least one eye, as defined by an MRSE within ± 0.25 D. The incidence of monovision among these patients was 34.2% (1638/4796). One-quarter (24.7%; 405/1638) of patients who achieved monovision had a myopic offset between 0.50 and 0.74 D, with more than one-third (35.2%; 576/1638) falling within 0.75-1.24 D and 18.0% within 1.25-1.74 D. A myopic offset ≥1.75 D was observed in 22.1% (362/1638) of patients who achieved monovision.

Conclusion

Pseudophakic monovision for presbyopia correction was achieved in ~34% of patients in the IRIS Registry bilaterally implanted with monofocal IOLs, with myopic offsets typically ranging from 0.5 to 1.24 D.

A systematic review of reading tests

Adequate near and intermediate visual capacity is important in performing everyday tasks, especially after the introduction of smartphones and computers in our professional and recreational activities. Primary objective of this study was to review all available reading tests both conventional and digital and explore their integrated characteristics. A systematic review of the recent literature regarding reading charts was performed based on the PubMed, Google Scholar, and Springer databases between February and March 2021. Data from 11 descriptive and 24 comparative studies were included in the present systematic review. Clinical settings are still dominated by conventional printed reading charts; however, the most prevalent of them (i.e., Jaeger type charts) are not validated. Reliable reading capacity assessment is done only by those that comply with the International Council of Ophthalmology (ICO) recommendations. Digital reading tests are gaining popularity both in clinical and research settings and are differentiated in standard computer-based applications that require installation either in a computer or a tablet (e.g., Advanced VISION Test and web-based ones e.g., Democritus Digital Acuity Reading Test requires no installation). It is evident that validated digital tests will prevail in future clinical or research settings and it is upon ophthalmologists to select the one most compatible with their examination routine.

Clinical Outcomes of a New Non-Diffractive Extended Depth-of-Focus Intraocular Lens Targeted for Mini-Monovision

Purpose

To assess visual acuity, binocular defocus curve, spectacle independence, and photic phenomena after bilateral same-day cataract surgery with implantation of an extended depth-of-focus intraocular lens (IOL) with mini-monovision.

Methods

Single-center retrospective study including 124 eyes from 62 patients who underwent bilateral implantation of an isofocal EDOF lens [Isopure® (BVI)] with mini-monovision (-0.50 D). Refraction, visual acuity at different distances, binocular defocus curves, spectacle independence, and subjective ratings of picture-referenced photic phenomena were assessed one to two months postoperatively.

Results

The mean postoperative refractive spherical equivalent was -0.15±0.41D in the dominant eyes and -0.46±0.35D in the mini-monovision eyes (p<0.01). Overall, 98.4% and 87.7% of the eyes were within ±1.00D and ±0.50D of the target refraction, respectively. Postoperative monocular corrected distance visual acuity was -0.04±0.07 logMAR. Binocular uncorrected visual acuity was -0.02±0.07, 0.13±0.11and 0.40±0.20 logMAR for far, intermediate and near, respectively. At the visual acuity threshold of 0.20 logMAR (or better) the defocus curve ranged from -1.6D to +0.9D. Reported spectacle-independence was 96% for far distance, 95% for intermediate, and 34% for near. Five percent of patients reported halos, 16% starburst, and 16% glare. Only 7% of all patients considered them bothersome.

Conclusion

In patients undergoing same-day bilateral cataract surgery, an isofocal EDOF lens provided an extended range of functional vision, up to 63 cm, resulting in useful uncorrected near vision, good uncorrected intermediate vision, and excellent uncorrected distance vision. Subjective patient satisfaction in terms of spectacle independence and photic phenomena was high.

Pharmacological Treatment in Presbyopia

Pharmacological treatment of presbyopia may be an alternative for those who want a spectacle-free scenario and an easy-to-use method with lower risk of irreversible ocular adverse events. There are two main agents, miotics and lens softeners, investigated as agents for the pharmacological treatment. Miotic agents treat presbyopia by creating a pinhole effect which may increase the depth of focus at all working distances. The miotic agents have been studied for application to only one eye for monovision or both eyes. Their effect is temporary with common adverse events, such as headache and dim vision at nighttime, with no known long-term safety and efficacy. There have been studies on the miotic agents in combination with other agents for additive treatment effects or lessening adverse events, however, these combination effects are not clear. Lens softeners increase the elasticity of the lens, which is targeted at one of the etiologic mechanisms of presbyopia. There is only one lens softener being investigated in only a few trials. The results were inconclusive. The recent approval of 1.25% pilocarpine for treatment of presbyopia by the US FDA may be an important milestone for investigation of real-world data of pharmacological treatment of presbyopia.

Clinical performance of presbyopia correction with a multifocal corneoscleral lens

AIM

To assess the clinical performance of a multifocal corneoscleral lens for the presbyopia correction.

METHODS

A prospective clinical trial of the Onefit™ A multifocal corneoscleral lens was conducted with 40 participants with presbyopia. At 4wk of continuous wear of the corneoscleral lens, changes in the distance, intermediate, and near visual acuity (VA) were evaluated. The safety of the corneoscleral lens, central corneal thickness (CCT), corneal endothelial cell count, binocular stereopsis, tear film break-up time (BUT), corneal staining, corneal edema, corneal neovascularization (NV), and conjunctival hyperemia were examined. In addition, a subjective questionnaire addressing satisfaction (rated from 1 to 5 points) and discomfort (rated from 1 to 5 points) was administered.

RESULTS

Forty participants were enrolled in this study. Six participants were excluded because of poor compliance with lens fitting (n=2) and loss to follow-up (n=4). The mean age of the participants was 53.0±4.9y. At 4wk of continuous wear of the corneoscleral lens, the best corrected far, intermediate, and near VA was 0.08±0.11, 0.10±0.12, and 0.10±0.12 logMAR, respectively. These results were significant improvements over the baseline uncorrected VA (far: P=0.004; intermediate: P=0.004; near: P=0.002). CCT, corneal endothelial cell count, binocular stereopsis, BUT, corneal staining, corneal edema, corneal NV, and conjunctival hyperemia were not significantly different between baseline and after corneoscleral lens use. The average satisfaction scores for fit sensation; corrected far, intermediate, and near VA; and ease of handling were 4.1, 3.4, 3.6, 3.5, and 3.4, respectively. The average discomfort scores for dryness, irritation, foreign body sensation, redness, fogging, and halo were 1.7, 1.8, 1.5, 1.7, 1.7, and 1.3, respectively.

CONCLUSION

Far, intermediate, and near VA are improved in presbyopic patients with the multifocal corneoscleral lens compared to uncorrected baseline VA, without adverse ocular effects. This evidence supports the safety and effectiveness of presbyopia correction with multifocal corneoscleral lenses.

Measuring aniseikonia tolerance range for stereoacuity - a tool for the refractive surgeon

Objective

No method exists to measure aniseikonia tolerance in stereoacuity. The brain can compensate for 2%–3% aniseikonia (i.e. 2–3 dioptres of anisometropia) without impairing stereoacuity; however, a substantial proportion of anisometropic patients experience problems caused by disruptions of sensory fusion due to surgically induced aniseikonia. We hypothesized that individual differences in tolerance to aniseikonia exist and sought to develop a method to measure aniseikonia tolerance.

Methods

A total of 21 eye‐healthy phakic individuals older than 50 years of age and 11 patients awaiting clear lens extraction were included. Patients were tested with best corrected near and distance visual acuity, cover/uncover test, eye dominance test, stereoacuity threshold (TNO test), slit lamp examination and ocular coherence tomography. The stereoacuity threshold was determined with aniseikonia induced by different size lenses ranging from 1% to 9% magnification of both eyes in increments of 1%. The aniseikonia tolerance range (ATR) was defined as the percentage aniseikonia in which the stereoacuity threshold was maintained.

Results

We examined 32 patients with a median age of 65 (95% CI: 62–66 years), CDVA better than 6/7.5 (0.1 logMAR), and median near visual acuity better than 6/6 (0.0 logMAR). The median stereoacuity threshold was 60 arcsec (maximum 30, minimum 120). We observed large inter‐individual differences in ATR: 6/31 (19%) participants had an ATR of ≤1%, 1/31 (3%) had an ATR of 1‐5%, 7/31 (22%) had an ATR of 5‐10%, and 17/31 (54%) had an ATR of >10%.

Conclusion

We present a reliable method for measuring the amount of aniseikonia that a person can tolerate without impairing stereopsis. We report large inter‐individual differences in tolerance of aniseikonia.

Psychophysical Tests Do Not Identify Ocular Dominance Consistently

Classical sighting or sensory tests are used in clinical practice to identify the dominant eye. Several psychophysical tests were recently proposed to quantify the magnitude of dominance but whether their results agree was never investigated. We addressed this question for the two most common psychophysical tests: The perceived-phase test, which measures the cyclopean appearance of dichoptically presented sinusoids of different phase, and the coherence-threshold test, which measures interocular differences in motion perception when signal and noise stimuli are presented dichoptically. We also checked for agreement with three classical tests (Worth 4-dot, Randot suppression, and Bagolini lenses). Psychophysical tests were administered in their conventional form and also using more dependable psychophysical methods. The results showed weak correlations between psychophysical measures of strength of dominance with inconsistent identification of the dominant eye across tests: Agreement on left-eye dominance, right-eye dominance, or nondominance by both tests occurred only for 11 of 40 observers (27.5%); the remaining 29 observers were classified differently by each test, including 14 cases (35%) of opposite classification (left-eye dominance by one test and right-eye dominance by the other). Classical tests also yielded conflicting results that did not agree well with classification based on psychophysical tests. The results are discussed in the context of determination of ocular dominance for clinical decisions.

Pseudophakic mini-monovision: high patient satisfaction, reduced spectacle dependence, and low cost

BACKGROUND

Cataract surgery with pseudophakic mini-monovision has lower out-of-pocket patient expense than premium multifocal intraocular lenses (IOL). The purpose of this study was to evaluate patient-reported satisfaction and spectacle dependence for key activities of daily living after cataract surgery with pseudophakic mini-monovision. The study also examined statistical relationships between patient demographic variables, visual acuity and satisfaction.

METHODS

Prospective cohort study of 56 patients (112 eyes) who underwent bilateral cataract surgery with pseudophakic mini-monovision. Mini-monovision corrects one eye for distance vision and the other eye is focused at near with - 0.75 to - 1.75 D of myopia. All patients with 1 diopter or greater of corneal astigmatism had a monofocal toric IOLs implanted or limbal relaxing incision. The main study outcomes were assessed at the last follow-up appointment and included refraction, visual acuity, patient reported spectacle use, and patient satisfaction. Descriptive statistics, correlation matrixes and Pearson's chi-square tests were examined.

RESULTS

Uncorrected visual acuity was significantly better post-operatively. Most patients reported the surgery met their expectations for decreased dependence on spectacles (93%). Most patients report little or no use of spectacles post-operatively for computer use (93%), distance viewing (93%) and general use throughout the day (87%). A small number of patients report spectacle use for reading (9%) and night driving (18%). There were no relationships detected between demographic variables and visual acuity or patient satisfaction.

CONCLUSIONS

Aging of the population presents one of the biggest challenges in the health sector, which includes a rising number of individuals with chronic vision impairment and increased demand for accessible treatment strategies. Cataract surgery with pseudophakic mini-monovision results in high patient satisfaction and considerable reduction in spectacle dependence. Pseudophakic mini-monovision technique is a low-cost, valuable option for patients who would like to reduce dependence on spectacles post-operatively and should be considered along with premium multifocal IOLs in options available for patients based on their needs, preferences and clinical indicators. Reducing spectacle dependence with the pseudophakic mini-monovision technique could improve the functionality, independence and quality of life for many patients who are unsuitable or are unable to pay additional fees associated with premium multifocal IOLs.