Managing low corneal astigmatism in patients with presbyopia correcting intraocular lenses: a narrative review.

Cataract surgery has become a refractive procedure in which emmetropia is the goal, with the implantation of extended depth-of-focus or multifocal intraocular lenses (IOLs) being the commonly selected option to restore vision beyond the far distance. The selection criteria for implanting these lenses can differ from those for monofocal IOLs and even between technologies, as eye characteristics can affect postoperative visual performance. Corneal astigmatism is an eye characteristic that can affect visual performance differently, depending on the implanted IOL. The magnitude of corneal astigmatism, the tolerance of the IOL to this astigmatism, economic aspects, comorbidities, and the efficacy of astigmatism treatment are factors that can make surgeons' doubt as to what astigmatism treatment should be applied to each patient. This review aims to summarize the current evidence related to low astigmatism tolerance in presbyopia-correcting lenses, the efficacy achieved through corneal incisions, and their comparison with the implantation of toric IOLs.

Population-based study on the epidemiology of dry eye disease and its association with presbyopia and other risk factors.

BACKGROUND: To investigate the incidence and prevalence of dry eye disease (DED) in Taiwan and to explore its potential risk factors. METHODS: Population-based longitudinal data from 2000 to 2013 based on Taiwan National Health Insurance Research Database were used in this study. To explore potential risks factor of interest, patients who had DED diagnosis before the exposure were excluded. Each patient from the exposure and his/her matched non-exposure controls were followed until either the diagnosis of DED or censorship. Kaplan-Meier method was used to compare the hazard of DED between cohorts. Stratified Cox proportional hazard models were applied to estimate the adjusted effect. RESULTS: The age-adjusted prevalence for men and women were 6.81% and 16.16%, respectively. The age-gender rate of the same period was 549 per 105 person-years. The propensity-adjusted hazard ratio of DED is 1.816 for the presbyopia versus non-presbyopia (with 95% CI = [1.737, 1.897] with p value < 0.0001). CONCLUSIONS: The DED incidence for women peaked at age 50-74, while that for men peaked at age ≧ 75. The incidence in young people seems stable both for women and for men. While exploring the factors of DED, there is a significant association between presbyopia and DED even after matching age/gender and comorbidity conditions. Further clinical studies are needed to justify whether the corrective refractive treatment such as presbyopic glasses to treat the frequently hyperopic status of these patients could be beneficial to both dry eye and presbyopic condition.

The effectiveness of sphero-cylindrical correction at a short distance in presbyopic age patients with the first detected astigmatism.

OBJECTIVE: Introduction: The practical results of optical correction without considering the cylindrical component at close dictance do not always satisfy the patient in everyday visual activity. The aim: Compare the effect of sphero-cylindrical and spherical correction in presbyopic patients with the first detected astigmatism at a close distance work. PATIENTS AND METHODS: Materials and methods: The article presents the results of a survey of 43 patients (86 eyes) aged 38 to 59 years, on average 47 ± 0.8 years. In all patients, weak astigmatism with a cylinder (Cyl) of 0.5 D to 1.0 D was found. At the diagnostic stage all patients were offered a variant of spherical and sphero-cylindrical optical correction, the data we obtained formed two groups of comparison. RESULTS: Results: The average value of visual acuity at close distance (33 cm) in patients with spherical correction was better - 0.95 ± 0.06 (73 ± 1.4 optotypes) compared with spherocylindrical correction - 0.61 ± 0.02 (64 ± 0.8 optotypes). The mean distance (66 cm) is better in patients with sphero-cylindrical correction - 1,58 ± 0,01 (70 ± 0,02 optotypes) compared with spherical correction - 0,8 ± 0,05 (55 ± 1,0 optotypes). Also, when using spherical correction, the nearest point of clear vision was closer to the eye, compared with sphero-cylindrical correction, but the range of depth of vision at close range was greater when using sphero-cylindrical correction. CONCLUSION: Conclusions: Sphero-cylindrical correction at a distance of 66 cm gives a clearer visual acuity - 1.58 ± 0.01 (70 ± 0.02 optotypes) compared with spherical - 0.8 ± 0.05 (55± 1.0 optotypes).

Visual complications in diabetes mellitus: beyond retinopathy.

Diabetic retinopathy is the most common cause of vision loss in people with diabetes mellitus; however, other causes of visual impairment/loss include other retinal and non-retinal visual problems, including glaucoma, age-related macular degeneration, non-arteritic anterior ischaemic optic neuropathy and cataracts. Additionally, when a person with diabetes complains of visual disturbance despite a visual acuity of 6/6, abnormalities in refraction, contrast sensitivity, straylight and amplitude of accommodation should be considered. We review and highlight these visual problems for physicians who manage people with diabetes to ensure timely referral and treatment to limit visual disability, which can have a significant impact on daily living, especially for those participating in sports and driving.

Efficacy and Safety of CSF-1 (0.4% Pilocarpine Hydrochloride) in Presbyopia: Pooled Results of the NEAR Phase 3 Randomized, Clinical Trials.

PURPOSE: This study was undertaken to evaluate the safety and efficacy of CSF-1 (0.4% pilocarpine hydrochloride ophthalmic solution) for use in individuals with presbyopia. METHODS: Two Phase 3 multicenter, randomized, double-masked, vehicle-controlled, parallel-group clinical trials were conducted in 35 private ophthalmology clinics in the United States from October 2020 to February 2022. Key inclusion criteria were the following: (1) age 45-64 years, (2) distance-corrected near visual acuity (DCNVA) at 40 cm ≥0.40 and ≤0.90 logarithm of the minimum angle of resolution (logMAR, approximately 20/50-20/160 Snellen) in at least 1 eye, (3) manifest refraction (MR) between -4.50 and +2.00 diopter (D) sphere in each eye with ≤2.00D difference between eyes, (4) <2.00D of cylinder MR in each eye, (5) ≤0.04 logMAR (20/20-2 or better) corrected distance visual acuity (CDVA) at 4 m in each eye. Key exclusion criteria were the following: (1) >0.14 logMAR (7 letters) improvement in post-vehicle treatment in monocular DCNVA in either eye at visit 1, (2) introcular pressure (IOP) <9 or >22 mm Hg, (3) average dark-adapted pupillometry <3.5 mm in either eye, (4) prior refractive surgery or intraocular lens (IOL) implantation. Participants applied CSF-1 or vehicle twice per day for 2 weeks. Efficacy and safety assessments were performed at several times on days 1, 8, and 15. Response was defined as ≥3-line gain in DCNVA without loss of ≥1-line in CDVA in the study eye under mesopic room lighting conditions. The primary efficacy endpoint was measured 1 hour post-dose 1 on day 8. Key secondary endpoints were 2 hours post-dose 1, and 1 and 2 hours post-dose 2, also on day 8. Safety endpoints were ocular and non-ocular treatment-related adverse events (TRAE), conjunctival redness, drop comfort, slit-lamp biomicroscopy, intraocular pressure, indirect fundoscopy, and CDVA at 4 m. FINDINGS: Six hundred thirteen participants were randomized to CSF-1 (n = 309) or vehicle (n = 304). Participants were predominantly White (80.8%) and female (62.0%), with mean age (standard deviation) of 54.7 (4.8). CSF-1 met the primary and key secondary endpoints. At the primary endpoint, 40.1% of the CSF-1 group achieved response versus 19.1% of the vehicle group (P < 0.0001). The percentage of responders was significantly greater in CSF-1 compared with vehicle at all tested times. Changes from baseline in all safety endpoints were comparable between groups. Most adverse events (AEs) were mild and transient. Neither serious nor severe AEs were reported with CSF-1. IMPLICATIONS: CSF-1, a low-dose pilocarpine ophthalmic solution, demonstrated superiority to vehicle in improving near vision in individuals with presbyopia without compromising distance vision. CSF-1 demonstrated a favorable safety profile. CLINICALTRIALS: gov identifier: NCT04599933 (NEAR-1), NCT04599972 (NEAR-2).

RHEGMATOGENOUS RETINAL DETACHMENT AFTER INITIATION OF PILOCARPINE HYDROCHLORIDE OPHTHALMIC SOLUTION 1.25% FOR TREATMENT OF PRESBYOPIA.

BACKGROUND/PURPOSE: Retinal detachment has previously been reported in association with topical miotic use for the treatment of glaucoma. Pilocarpine hydrochloride 1.25% was recently approved by the Food and Drug Administration for the treatment of presbyopia, with no reports of associated retinal detachments in the clinical trial data. METHODS: Case report. RESULTS: Two novel cases of unilateral retinal detachment occurring within 10 days of the initiation of pilocarpine 1.25% for the treatment of presbyopia were described. The patients were pseudophakic men in their 60s or 70s with preexisting retinal detachment risk factors, such as high myopia, lattice degeneration, and prior retinal detachment. Both affected eyes were treated with pars plana vitrectomy and gas endotamponade with an uncomplicated postoperative course. CONCLUSION: Retinal detachment may be associated with the use of pilocarpine 1.25%. Caution should be used when considering prescribing this medication in patients with preexisting retinal abnormality.

Nationwide Rapid Assessment of Avoidable Blindness (RAAB) in Armenia.

PURPOSE: This study aimed to estimate the prevalence and main causes of blindness and visual impairment in population aged 50 years and older in Armenia using Rapid Assessment of Avoidable Blindness (RAAB) methodology. METHODS: The study team randomly selected 50 clusters (each consisting of 50 people) from all 11 regions of Armenia. Data on participants' demographics, presenting visual acuity, pinhole visual acuity, principal cause of presenting visual acuity, spectacle coverage, uncorrected refractive error (URE), and presbyopia were collected using the RAAB survey form. Four teams of trained eye care professionals completed data collection in 2019. RESULTS: Overall, 2,258 people of 50 years and older participated in the study. The age- and gender- adjusted prevalence of bilateral blindness, severe and moderate visual impairment were 1.5% (95% CI: 1.0-2.1), 1.6% (95% CI: 1.0-2.2) and 6.6% (95% CI: 5.5-7.7), respectively.The main causes of blindness were cataract (43.9%) and glaucoma (17.1%). About 54.6% and 35.3% of participants had URE and uncorrected presbyopia, respectively. The prevalence of bilateral blindness and functional low vision increased with age and was the highest in participants 80 years and older. CONCLUSION: The rate of bilateral blindness was comparable with findings from countries that share similar background and confirmed that untreated cataract was the main cause of blindness. Given that cataract blindness is avoidable, strategies should be developed aiming to further increase the volume and quality of cataract care in Armenia.

[Regularities of structural and functional visual system changes in patients with myopic refraction and presbyopia].

Two age groups of 57 patients with noncomplicated low or moderate myopia were examined to reveal the regularities of structural and functional visual system changes in patients with myopic refraction and presbyopia. Characteristics of visual impression, anatomic and physiologic parameters were studied. Presbyopia development in patients with myopic refraction was found to occur on the background of significant changes in anatomic proportions and optic parameters of the eye, decrease of functional capability of visual system and development of abnormal functional system of visual perception. The key mechanisms of presbyopia development in myopia besides the accommodation decrease are pupil dysfunction and binocular interactions disintegration i. e. all the near vision reflex components.

Prevalence and determinants of asthenopia among ophthalmologists in China: a national cross-sectional survey.

Introduction: The role of ophthalmologists is defined by tasks requiring visual effort, emphasizing the importance of examining their condition within the realm of occupational visual health. Our goal was to explore the occurrence of asthenopia among Chinese ophthalmologists and identify contributing factors through the use of a reliable and validated survey instrument. Methods: A national cross-sectional online survey was carried out in June 2017, involving 6,220 practicing ophthalmologists in China. Utilizing an 11-item Asthenopia Survey Questionnaire with established reliability and validity. Prevalence rates of asthenopia among subgroups categorized by age, gender, hospital classification, physician level, daily near vision activity duration, sleep duration, sleep quality, presbyopia status, and history of eye surgery were determined using the independent t-test, chi-square test and bonferroni test. Multiple logistic regression analysis was employed to pinpoint independent factors linked to asthenopia. Results: Out of the 5,009 ophthalmologists who completed the survey, a 40.7% prevalence of asthenopia was identified. Multivariate analysis revealed that good sleep quality (OR: 0.24, 95%CI: 0.20-0.30), moderate sleep quality (OR: 0.47, 95%CI: 0.38-0.59), engaging in daily near vision activities for less than 7 h (OR: 0.76, 95%CI: 0.68-0.86), having daily sleep duration exceeding 7 h (OR: 0.87, 95%CI: 0.77-0.98), and working in tertiary hospitals (OR: 0.88, 95%CI: 0.78-0.99) were protective factors against asthenopia. Conversely, presbyopia was identified as a risk factor (OR: 1.33, 95%CI: 1.04-1.70). All calculated p values were below 0.05. Age, gender, physician level, and eye surgery history were not related factors. Conclusion: Asthenopia is prevalent among Chinese ophthalmologists, with employment in tertiary hospitals providing a protective effect and presbyopia is a risk factor. Preventive strategies include improving sleep quality, restricting daily near vision activity to under 7 h, and extending daily sleep duration to over 7 h. Further investigation is needed to explore the protective implications of working in tertiary hospitals.

Do reading additions improve reading in pre-presbyopes with low vision?

PURPOSE: This study compared three different methods of determining a reading addition and the possible improvement on reading performance in children and young adults with low vision. METHODS: Twenty-eight participants with low vision, aged 8 to 32 years, took part in the study. Reading additions were determined with (a) a modified Nott dynamic retinoscopy, (b) a subjective method, and (c) an age-based formula. Reading performance was assessed with MNREAD-style reading charts at 12.5 cm, with and without each reading addition in random order. Outcome measures were reading speed, critical print size, MNREAD threshold, and the area under the reading speed curve. RESULTS: For the whole group, there was no significant improvement in reading performance with any of the additions. When participants with normal accommodation at 12.5 cm were excluded, the area under the reading speed curve was significantly greater with all reading additions compared with no addition (p = 0.031, 0.028, and 0.028, respectively). Also, the reading acuity threshold was significantly better with all reading additions compared with no addition (p = 0.014, 0.030, and 0.036, respectively). Distance and near visual acuity, age, and contrast sensitivity did not predict improvement with a reading addition. All, but one, of the participants who showed a significant improvement in reading with an addition had reduced accommodation. CONCLUSIONS: A reading addition may improve reading performance for young people with low vision and should be considered as part of a low vision assessment, particularly when accommodation is reduced.

[Evaluation of visual perception in multifocal IOL implantation with different presbyopic shift using results of visual acuity defocusing].

Defocusing of visual acuity was performed in 102 patients after cataract surgery with binocular implantation of multifocal IOL of refractive type "Rayner" with different presbyopic shift and their combinations: 3/3, 4/4 and 3/4 D. The best stability of different distance visual acuity was observed in anisomultifocal implantation, that optimizes pseudoaccommodative visual perception.

Presbyopia correction with a new Extended Depth of Focus Intraocular Lens.

Extended depth of focus intraocular lenses (EDoF IOLs) offer an expanded number of modalities for simultaneous cataract and presbyopia treatment. The objective of the current study was to assess clinical outcomes with a new mono-EDoF intraocular lens and to analyze the effect of different parameters on postoperative results. The inclusion criteria were defined as uneventful cataract surgery, no history of concomitant ocular disease, implantation of ZOE Primus-HD lens. Parameters from IOL Master 500 were analyzed. The main outcome measures were postoperative uncorrected distance (UDVA) and intermediate (UIVA) visual acuity. The study included 39 eyes of 37 patients (15 males and 22 females) with a mean age of 73.59±7.71. Postoperatively, the UDVA improved to 0.84±0.16 (p<0.001) and UIVA was 0.86±0.14. There was no correlation between K1, K2 and IOL power with both postoperative UDVA and IDVA. Moreover, there was no statistically significant difference between UDVA and UIVA between patients with mean K value over or under 44.0D (p=0.204 and p=0.817, respectively). The results of a multinomial logistic regression analysis for the predictive value of the factors K1, K2 and IOL power demonstrated no statistical significance, except for UIVA with a significant influence of IOL power (p=0.024) in patients with less than 0.9 Snellen visual acuity. The implantation of the new mono-EDoF ZOE Primus-HD lens led to improvement in both UDVA and UIVA. Patients with keratometry values less than 44.0D could still benefit from the mono-EDoF lenses. Further studies including wavefront aberrometry are needed to study the interaction between corneal aberrations and EDoF IOLs. Abbreviations: IOL = Intraocular lens, UDVA = Uncorrected distance visual acuity, UIVA = Uncorrected intermediate visual acuity, D = Diopters, EDoF = Enhanced Depth of Focus, MF IOL = Multifocal intraocular lens, AUC = area under the curve.

Retinal Detachments Associated With Topical Pilocarpine Use for Presbyopia.

PURPOSE: To present a case series of retinal detachments associated with the use of pilocarpine for presbyopia. DESIGN: Multicenter case series of 3 eyes from 2 patients. RESULTS: Patient 1, a 47-year-old man, presented with flashes and floaters in both eyes. The patient had started pilocarpine 1.25% drops 1 month prior for presbyopia in both eyes. He noted the onset of flashes and floaters 3 days after he initiated the drops. A dilated examination revealed an inferotemporal retinal detachment in the right eye with an associated retinal tear inferotemporally. The left eye demonstrated a retinal detachment in the superior quadrant with an associated horseshoe tear at 12 o'clock. Patient 2, a 46-year-old man, presented 5 weeks after initiating topical pilocarpine 1.25% drops for presbyopia. He noted a nasal visual field defect in his left eye that progressed to include his central vision. A dilated examination revealed a superior retinal detachment from 11 to 3 o'clock with subretinal fluid extending into the macula. CONCLUSIONS: Pilocarpine and other miotics have long been suspected to be associated with an increased risk of retinal detachment. Prior to prescribing pilocarpine for presbyopia, physicians should inform patients of this potential adverse event and consider that these patients undergo a screening dilated examination, particularly if they are myopic, to determine if they are at higher risk for retinal detachment. Before the initiation of therapy, patients should be appropriately informed regarding symptoms of retinal tears or detachment, which include flashes, floaters, and visual field loss.

Aspheric wavefront-guided LASIK to treat hyperopic presbyopia: 12-month results with the VISX platform.

PURPOSE: To evaluate an aspheric ablation profile to improve near vision in presbyopic patients with hyperopia and to outline the key factors of success. METHODS: A prospective, nonrandomized, clinical trial of 66 eyes of 33 hyperopic patients who underwent customized bilateral refractive surgery, which included an aspheric presbyopia treatment shape and wavefront-driven hyperopic treatment, was studied. Surgeries were performed using the VISX STAR S4 or STAR S4 IR excimer laser system (Abbott Medical Optics). Mean preoperative refractive error was +1.77 ± 0.56 diopters (D) sphere (range: 0.75 to 3.50 D) with 0.41 ± 0.34 D cylinder (range: 0.00 to 1.50 D). All patients received full distance refractive correction. No patients received monovision or were intentionally left with residual myopia. Patient satisfaction results were evaluated using a questionnaire with a 5-point scale. RESULTS: Sixty eyes completed 6-month and 50 eyes completed 12-month postoperative follow-up. At 6 months, mean corrected distance visual acuity (CDVA) was 20/20±1 line (range: 20/25 to 20/10). Mean gain in distance-corrected near visual acuity (DCNVA) was 2.7 ± 1.7 lines with a maximum of 6 lines of near. Spectacle dependence for tasks, such as reading and computer use, was reduced. At 12 months, 100% of patients had achieved binocular simultaneous uncorrected vision of 20/25 or better and J3. Refraction was stable over 12 months. Contrast sensitivity reduction was clinically insignificant (1 step or 0.15 logCS). Negative spherical aberration highly correlated with postoperative improvement of DCNVA. Patients who had a larger amount of preoperative hyperopia or a greater decrease of preoperative DCNVA were more likely to have overall satisfaction. CONCLUSIONS: The aspheric ablation designed to expand near functional vision was effective and stable over 12 months. The wavefront-customized hyperopic treatment significantly reduced spectacle dependence.

Trends in prevalence of blindness and distance and near vision impairment over 30 years: an analysis for the Global Burden of Disease Study.

BACKGROUND: To contribute to the WHO initiative, VISION 2020: The Right to Sight, an assessment of global vision impairment in 2020 and temporal change is needed. We aimed to extensively update estimates of global vision loss burden, presenting estimates for 2020, temporal change over three decades between 1990-2020, and forecasts for 2050. METHODS: We did a systematic review and meta-analysis of population-based surveys of eye disease from January, 1980, to October, 2018. Only studies with samples representative of the population and with clearly defined visual acuity testing protocols were included. We fitted hierarchical models to estimate 2020 prevalence (with 95% uncertainty intervals [UIs]) of mild vision impairment (presenting visual acuity ≥6/18 and <6/12), moderate and severe vision impairment (<6/18 to 3/60), and blindness (<3/60 or less than 10° visual field around central fixation); and vision impairment from uncorrected presbyopia (presenting near vision

Presbyopia developed earlier during the COVID-19 pandemic.

PURPOSE: The aim of this cohort study was to evaluate the development and progression of presbyopia and the status of dry eye-related symptoms from 2017 to 2020, to assess the impact of the COVID-19 pandemic. METHODS: Near add power at 30 cm was measured in 339 participants aged between 40 and 55 from 2017 to 2021 at Japanese eye clinics. Regression analysis of near add power and age was analyzed to compare 2017 with later years up to the pandemic. The prevalence of dry eye-related signs and six common symptoms were compared. RESULTS: The number and mean age (y) of participants were 183 (48.6±4.1) in 2017, 46 (51.3±7.5) in 2019, and 110 (49.2±3.7) in 2020-21, respectively. The mean progression rate of near add power (D/y) was 0.13 for 2017, 0.09 for 2019 (P = 0.028, vs 2017), and 0.08 for 2020-21 (P<0.001, vs 2017). The slope (rate of presbyopia progression) became flatter from 2017 to 2021 and the estimated near add power at the age of 40 increased from 2017 to 2020-2021, implicating presbyopia developed earlier and worsened during the study period. The 2017 values were comparable with previous studies described in 1922 and 2019. The standardized correlation coefficient between age and near add power was 0.816 for 2017, 0.671 for 2019 (P = 0.084, vs 2017), and 0.572 for 2020-21 (P<0.001, vs 2017). Multiple regression analysis revealed age and COVID-19 pandemic were significantly correlated with near add power. The prevalence of dryness irritation, and pain was greater in 2020-21 than in 2017 with no difference in the prevalence of eye fatigue, blurring, and photophobia. There was no difference in the prevalence of short tear break-up time and positive corneal staining among 2017, 2019 and 2020-21. CONCLUSION: Estimated presbyopia developed earlier and progressed slower from 2017 to 2021, the COVID-19 pandemic. Stress and rapid digitalization related to strict infection control and quarantine might be contributing factors.

Non-verbal visual reinforcement affects speech audiometry in the elderly.

The purpose of this study was to investigate how non-verbal visual reinforcement provided by the audiologist during speech testing influences performance in the elderly. Thirty-two volunteers with age-related hearing loss with or without dual sensory-impairment (DSI), were administered a speech audiometry test in which they repeated lists of ten disyllabic words in two different conditions, namely with and without visual reinforcement. In the conditions of "with visual reinforcement", the tester provided non-verbal cues to acknowledge the response of each participant. The "visual reinforcement" condition did not apparently provide any significant variation in the results. However, when we considered the group of patients without DSI, the non-verbal "visual reinforcement" resulted in better scores (p < 0.001). Non-verbal visual reinforcement may influence speech audiometry results in the elderly. During speech testing of elderly people with age-related hearing loss, audiologists should always remember to administer visual reinforcement to the patients in order to remove a possible confounding factor from audiological evaluation.

Thirty Year Projected Magnitude (to 2050) of Near and Distance Vision Impairment and the Economic Impact if Existing Solutions are Implemented Globally.

Purpose: Recent global, regional and country-level prevalence estimates for blindness and vision impairment will be important when designing future public health policies. The aim of this paper is to contribute to this discussion by estimating the productivity impact of known effective interventions to treat all preventable cases of vision impairment at the global, regional and country-level up to 2050. We also provide estimates of potential reduction in the number of people with vision impairment, as well as averted vision-impaired years up to 2050.Methods: We combined recent estimates of the prevalence of blindness, distance and near vision impairment with the World Bank's World Development Indicators (WDI) and estimated the global, regional and country-level productivity gains up to 2030, 2040 and 2050 from known effective interventions, primarily cataract surgery and treated uncorrected refractive errors. The magnitude of productivity gains relative to baseline depended on population size, estimated current and future prevalence of vision impairment, level of economic development, long-term wage growth, and long-term real interest rates.Results: Globally, we estimate that the number of people affected by blindness could be reduced from the estimated 114.6 million by 2050 to 58.3 million. This would be associated with over one billion blind life-years averted and US$ 984 billion in global productivity gains. These numbers are dwarfed by the impact of interventions to reduce the prevalence of Moderate and Severe Vision Impairment (MSVI) [Presenting Acuity <20/60 to 20/400 in the better-seeing eye]. We estimate that the number of people affected by MSVI could be reduced by 435.8 million people to 147.9 million by 2050. This reduction would translate to over 9 billion MSVI -life-years avoided and US$ 17 trillion in productivity gains by 2050. While other causes of VI would not be possible to eliminate completely based on current known effective treatments, low-cost interventions to eliminate VI from uncorrected presbyopia would avert 1.2 billion presbyopia life-years and achieve US$ 1.05 trillion in productivity gains by 2050. In total, the global productivity gains for all three categories are estimated to be US$ 19 trillion by 2050. East Asia makes up the greatest share of productivity gains due to the high number of people affected by VI and the region's continuing economic growth.Conclusion: Implementation of currently known and effective treatments of avoidable blindness, MSVI and presbyopia would be expected to contribute significant productivity gains to the global economy at a fraction of the estimated costs to deliver them.

Presbyopia-correcting intraocular lenses.

PURPOSE OF REVIEW: Multifocal and accommodating intraocular lenses (IOLs) were introduced 2 decades ago and have gone through several iterations. This technology has allowed ophthalmologists to provide their cataract surgery patients with a broader range of visual function. The purpose of this article is to discuss the currently available presbyopia-correcting IOLs, the role of patient selection, and future technologies. RECENT FINDINGS: Newer versions of both the multifocal and accommodating IOLs offer better vision at distance, intermediate, and near than their predecessors. The procedure remains attractive for patients with cataracts or those who are too hyperopic for corneal surgery. However, following successful implantation of the latest generation of lenses, some patients are still not completely satisfied with their visual results. Additional procedures, such as yttrium aluminum garnet (YAG) capsulotomies or reduction of astigmatism and refractive error or both, may be required to increase patient satisfaction. SUMMARY: Experience has shown us that the majority of patients who present with cataracts are potential candidates for multifocal or accommodating IOLs. Familiarity with accommodative and multifocal lenses, in conjunction with careful patient selection, maximizes surgical success in this challenging group of surgical patients.

Effectiveness of base in prism for presbyopes with convergence insufficiency.

PURPOSE: Although the treatment of symptomatic convergence insufficiency (CI) with base-in (BI) prism in adults has a strong theoretical foundation, there have been very few studies addressing its efficacy. The purpose of this study was to investigate whether the application of BI prism, using a novel progressive addition lens design which incorporates BI prism in the near portion only, could help alleviate the symptoms in presbyopes with CI. METHODS: A total of 29 symptomatic CI subjects aged 45 to 68 years were examined. All subjects took the CI Symptom Survey V-15 (CISS) and scored >or=16 points. Each subject was assigned two pairs of progressive addition glasses made by the same manufacturer in a randomized sequence, one with BI prism and one with the same lens prescription but no prism (placebo). Subjects wore each pair of glasses for 3 weeks and completed the CISS at the end of the 3rd week. Symptom level measured with CISS was the major outcome measure. RESULTS: The mean (standard deviation) CISS score was 30.21 (9.30) at baseline and decreased to 13.38 (9.44) with the BI-prism glasses, vs. 23.62 (10.76) with the placebo glasses. There were significant differences between the baseline survey score and the score with the BI-prism glasses (p < 0.0001) and between the score with placebo glasses and the one with BI-prism glasses (p = 0.001). CONCLUSIONS: The progressive addition glasses with BI-prism were found to be effective in alleviating symptoms of presbyopes with symptomatic CI.