Tendencias actuales en el manejo clínico quirúrgico de la presbicia

La presbicia es la pérdida gradual y progresiva de la amplitud de acomodación del cristalino que comienza entre los 38 y 40 años de edad y culmina a los 55 años al perderse por completo. Es provocada por el aumento de rigidez del cristalino y, en particular, un mayor cambio en la rigidez del núcleo de su corteza. La presbicia no corregida o hipocorregida tiene un impacto negativo en la calidad de vida en relación con la visión, las personas afectadas experimentan un cambio positivo significativo de productividad en sus actividades diarias al utilizar una corrección óptica adecuada. Las diferentes alternativas de tratamiento deben aplicarse de forma personalizadas para optimizar el rango de enfoque para las tareas diarias, minimizar los efectos visuales adversos y cumplir con las expectativas del paciente según necesidades y alcance económico. Los tratamientos más efectivos y con menos efectos indeseables hasta el momento son los dispositivos ópticos como las gafas y las lentes de contacto. Los métodos quirúrgicos pueden dejar síntomas visuales. El objetivo de este estudio fue realizar una búsqueda bibliográfica sobre las actuales tendencias en el manejo clínico-quirúrgico de la presbicia.

Presbyopia is the gradual and progressive loss of the accommodative range of the crystalline lens that begins between 38 and 40 years of age and culminates at 55 years of age when it is completely lost. It is caused by increased stiffness of the lens and, in particular, a greater change in the stiffness of the nucleus of its cortex. Uncorrected or undercorrected presbyopia has a negative impact on quality of life in relation to vision, affected individuals experience a significant positive change in productivity in their daily activities when using an appropriate optical correction. The different treatment alternatives should be applied in a personalized way to optimize the range of focus for daily tasks, minimize adverse visual effects and meet the patient's expectations according to needs and economic scope. The most effective treatments with the least undesirable effects so far are optical devices such as glasses and contact lenses. Surgical methods may leave visual symptoms. The aim of this study was to perform a literature search on current trends in the clinical-surgical management of presbyopia.

Multifocal versus modified monovision corrections: A non-dispensing comparison of visual assessment in presbyopic neophytes

Purpose: To compare the visual performance of two simultaneous?vision soft multifocal contact lenses and to compare multifocal contact lens and its modified monovision counterpart in presbyopic neophytes. Methods: A double?masked, prospective, comparative study was conducted on 19 participants fitted with soft PureVision2 multifocal (PVMF) and clariti multifocal (CMF) lenses in random order. High? and low?contrast distance visual acuity, near visual acuity, stereopsis, contrast sensitivity, and glare acuity were measured. The measurements were conducted using multifocal and modified monovision design with one brand and then repeated with another brand of lens. Results: High?contrast distance visual acuity showed a significant difference between CMF (0.00 [?0.10–0.04]) and PureVision2 modified monovision (PVMMV; ?0.10 [?0.14–0.00]) correction (P = 0.003) and also between CMF and clariti modified monovision (CMMV; ?0.10 [?0.20–0.00]) correction (P = 0.002). Both modified monovision lenses outperformed CMF. The current study did not show any statistically significant difference between contact lens corrections for low?contrast visual acuity, near visual acuity, and contrast sensitivity (P > 0.01). Stereopsis at near distance was significantly lower with both modified monovision (PVMMV: 70 [50–85]; P = 0.007, CMMV: 70 [70–100]; P = 0.006) and with CMF (50 [40–70]; P = 0.005) when compared to spectacles (50 [30–70]). Glare acuity was significantly lower with multifocal (PVMF: 0.46 [0.40–0.50]; P = 0.001, CMF: 0.40 [0.40–0.46]; P = 0.007) compared with spectacles (0.40 [0.30–0.40]), but no significant difference was noted between the multifocal contact lenses (P = 0.033). Conclusion: Modified monovision provided superior high?contrast vision compared to multifocal correction. Multifocal corrections performed better for stereopsis when compared to modified monovision. In parameters like low?contrast visual acuity, near acuity, and contrast sensitivity, both the corrections performed similarly. Both multifocal designs showed comparable visual performances.

A Novel Dual-wavelength, Dual-function Laser System for Presbyopia and Glaucoma Treatments

To update the accommodation mechanisms and propose a dual-wavelength, dual-function laser system for presbyopia and glaucoma treatments.Study Design: Laser sclera softening (LSS) for increased accommodation of presbyopic eyes.Place and Duration of Study: New Taipei City, Taiwan, between Jan., 2023 and Feb., 2023.Methodology: Accommodation gain (AG) can be improved by: (i) thermal shrinkage of the scleral stroma and ciliary body, or (ii) softening of the scleral stroma (with temperature range of 700C to 900C), such that the the lens front and back curvature change (or lens thickening), leading to the thickening of ciliary body and its apex, and the increase of the space of ciliary body and lens equation (SCL), and the length of the posterior vitreal zonules (PVZ) increases.Results: A novel dual-color laser system having wavelength A and B, acting on the front-zone and back-zone of the sclera, respectively, where laser-A has a deep thermal penetration the sclera and ciliary body (CB) (0.5 to 1.0 mm); and laser-B has a shallow penetration depth in the sclera (0.3 to 0.5 mm), based on the optical property of the sclera. Laser-A (having a wavelength about0.8 to 0.98 um) leads to thermal shrinkage of the ciliary body such that the CLS is increased for accommodation gain which is much more effective than the prior art.Conclusion: The increase of AG can be achieved by scleral softening and ciliary body shrinkage which increase the SCL. A proposed novel dual-color laser system acting on the front-zone and back-zone of the sclera, respectively, could provide higher AG than that of single wavelength, or prior arts using scleral ablation. However, further clinical studies are required to justified the proposed novel system with predicted advantages and efficacy based on the optical properties of sclera.

A prospective study of a new presbyopia pseudophakic intraocular lens: Safety, efficacy and satisfaction

Purpose: To evaluate the safety, visual performance, and patient satisfaction of a new presbyopic pseudophakic intraocular lens (IOL). Methods: A prospective non?randomized case?series study was performed in Buenos Aires, Argentina. Patients included in the study underwent a programmed Femtosecond laser assisted cataract surgery (FLACS), performed between October and December 2020, with a 6?month follow?up period. The Intensity (Hanita Lenses) IOL was bilaterally implanted. Spherical equivalent (SE) refraction, uncorrected distance and near visual acuity (UDVA/UNVA), defocus curve, endothelial cell density (ECD), central corneal thickness (CCT), and a satisfaction questionnaire were evaluated. Results: A total of 56 patients (112 eyes), aged 65 ± 6.12 years were included. The mean ± SD of preoperative SE was 1.85 ± 2.24 D (range; ?4.50 to 4.75), which had decreased 6 months after surgery to ?0.08 ±0.32 D (range; ?0.75 to 0.63). No eyes experienced a loss of lines of vision, and 94% obtained SE values between ± 0.50 D. Defocus curve for different additions was 0.03 LogMAR (logarithm of the minimum angle of resolution) for ?3.0 D, ?0.005 LogMAR for ?1.5 D, and ?0.07 LogMAR for 0 D. The ECD, CCT remained stable (P: 0.09 and 0.58, respectively) and all patients achieved their preoperative expectations, with a 6?month follow?up period. Conclusion: Patients who underwent a safe bilateral implantation with Intensity IOL achieved a high degree of spectacle independence and satisfaction, 6 months after surgery.

Accommodative Gain in Presbyopic Eye Using a New Procedure of Laser Scleral Softening (LSS): Part-II. Formulas for Volume Efficacy

Purpose: To derive and provide, for the first time, comprehensive analytic formulas for scleral softening volume efficacy (SVE) for accommodative gain (AG) via the increased space between ciliary body and lens (SCL) and mobility of the posterior vitreous zonules (PVZ).Study Design: To increase the AG of presbyopic eye by a new procedure, laser scleral softening (LSS).Place and Duration of Study: New Taipei City, Taiwan, between June 2022 and July 2022.Methodology: The SVE is calculated based on the time and spatial integral of the scleral temperature profiles, T(z,t), solutions of a heat diffusion equation. Analytic formulas for SVE is derived based on the covered area given by a triangle area. The SVE of a 3-D model is governed by the "volume" covered by the laser beam, or its spot size area, the effective penetration depth (z"), which is an increasing function of laser dose, but a decreasing function of the absorption coefficient (A), due to the Beer's law of laser intensity, I(z)=I0exp(-Az). The efficacy depth-range (dZ) and time-ranges (dT) are defined for efficient softening with T(z,t)>T*, where T* is the scleral softening threshold temperature.Results: The accommodative gain is proportional to the 3-D SVE given by: SEV(3D) = SEV(1D) x laser beam spot (2-D area) x total number of spots (N) acting on the sclera, which is proportional to the efficacy ranges dZ and dT, in which dZ is an increasing of laser irradiation time, whereas dT is a decreasing function of depth. Softening of the scleral tissue after a thermal laser leading to the increase of PVZ mobility and SCL. However, the actual relation of SVE and the PVZ and SCL changes require measured data.Conclusion: Safety and efficacy of scleral softening for presbyopia treatment depend upon the laser parameters (intensity, dose, spot size, wavelength) and the effective depths. The SVE is proportional to the efficacy depth-range (dZ) and time-range (dT), in which dZ is an increasing of laser irradiation time and dT is a decreasing function of depth. The AG is proportional to the SVE(in 3-D).

Efficacy Theory and Proposed Protocol for Presbyopia Correction using Scleral Softening by Non-invasive Infrared Diode Lasers

Purpose: To derive and provide analytic formulas and proposed protocol for accommodative gain of presbyopia eyes via laser scleral softening, which causes increased space between ciliary body and lens (SCL) and mobility of the posterior vitreal zonules (PVZ).Study Design: To increase the accommodation of presbyopia by laser scleral heating/softening.Place and Duration of Study: New Taipei City, Taiwan, between April 2022 and June 2022.Purpose: To analyze the safety and efficacy of presbyopia treatment via scleral softening.Methodology: The scleral softening efficacy is calculated based on the rate equation of scleral tissue with a rate coefficient given by an Arrhenius formula, Temperature spatial and temporal profiles are given by the numerical solutions of a heat diffusion equation with a volume heating source. Various effective depths including tissue damage depth, temperature penetration depth and conversion depth, governed by tissue absorption coefficient, light intensity and dose (or irradiation time), and the related threshold values, are introduced in replacing the conventional penetration depth based on a Beer's law.Results: Given the the temperature spatial and temporal profiles, scleral softening efficacy can be calculated. Scleral surface damage can be prevented by cooling window. The suggested protocol for scleral softening treatments include: a diode laser at about 1.45 to 1.5 祄 or about 1.86 to1.9 祄, or about 2.0 to 2.15 祄, wavelength (with absorption coefficient about 20 to 100 cm-1); laser power about 0.2 to 0.8 W per spot, having a total of 4 to 16 spots; and irradiation time of 100 to 600 ms. Results of corneal thermal shrinkage are demonstrated by the topography changes of pig eyes, in which the scleral softening does not affect the corneal shapes. The accommodative gain is proportional to the softening efficacy (Seff) of the scleral tissue after a thermal laser leading to the increase of PVZ mobility and SCL. However, the actual relation of Seff and the PVZ and SCL changes require measured data.Conclusion: Safety and efficacy of scleral softening for presbyopia treatment depend upon the laser parameters (intensity, dose, spot size, wavelength) and the effective depths. By choosing the laser treated areas, a dual function treatment using scleral softening for presbyopia, and cornea stromal shrinkage for hyperopia is proposed and demonstrated by topography of pig eyes.

Refractive errors among commercial drivers

Purpose: To determine the pattern of refractive error among commercial drivers in north India. Methods: Descriptive study with convenient sampling conducted among commercial drivers of north India. Results: A total of 213 (75.8%) heavy?vehicle and 68 (24.2%) light?vehicle drivers were screened for eye diseases. Refractive error for distance was reported in 44 (15.7%; 95% CI: 11.6–20.4) drivers. Hyperopia was reported in 23 (8.2%; 95% CI: 5.2–12) drivers, followed by myopia in 15 (5.3%; 95% CI: 3–8.6) drivers and astigmatism in six (2.1%; 95% CI: 0.7–4.5) drivers. Presbyopia was reported in 157 (55.8%) drivers. Dry eye was reported in 70 (24.9%), stereo deficiency in 77 (27.4%), and color vision deficiency in 11 (3.9%) drivers. Three drivers were diagnosed with cataract, and two were referred for retina evaluation. Conclusion: Hyperopia in both eyes was the most common refractive error. Dry eye disease and color vision deficiency were also reported. Most of the drivers were not using spectacles for refractive error correction. Due to their mobile nature, drivers with cataract and retina diseases did not turn up for follow?up.

Effect of Wei's triple nine needling on eye regulation in patients with presbyopia complicated with visual fatigue of liver depression and spleen deficiency / 中国针灸

OBJECTIVE@#To compare the clinical efficacy between Wei's triple nine needling combined with esculin and digitalis glycosides eye drops and esculin and digitalis glycosides eye drops alone for presbyopia complicated with visual fatigue of liver depression and spleen deficiency.@*METHODS@#Forty-six cases (92 eyes) with presbyopia complicated with visual fatigue of liver depression and spleen deficiency were randomly divided into an observation group (23 cases) and a control group (23 cases, 2 cases dropped off). The cases in the observation group were treated with Wei's triple nine needling and esculin and digitalis glycosides eye drops. The acupoints included Shangming (Extra), Chengqi (ST 1), Cuanzhu (BL 2) to Jingming (BL 1), Sizhukong (TE 23) to Taiyang (EX-HN 5), etc; the needling was given once every other day, three times a week, and the eye drops were given one drop each time, three times a day. The cases in the control group were only treated with the eye drops. Both groups were treated for 7 days as one course of treatment, and 2 courses of treatment were given. The visual fatigue core symptoms score, adjustment amplitude, adjustment lag and best average corrected visual acuity were observed in the two groups before treatment, 1 week and 2 weeks into treatment, respectively.@*RESULTS@#Compared before treatment, the visual fatigue core symptoms scores in the two groups were decreased after 1-week and 2-week treatment (P<0.05); in the observation group, the adjustment amplitude was increased after 2-week treatment (P<0.05), while in the control group, the adjustment amplitude was increased after 1-week and 2-week treatment (P<0.05); in the observation group, the adjustment lag was decreased after 1-week and 2-week treatment (P<0.05). After 2-week treatment, the visual fatigue core symptoms score in the observation group was lower than that in the control group, and the adjustment amplitude was higher than that in the control group (P<0.05). There were no significant differences in adjustment lag and best average corrected visual acuity between the two groups after 1-week and 2-week treatment (P>0.05).@*CONCLUSION@#Wei's triple nine needling combined with esculin and digitalis glycosides eye drops could improve the visual fatigue and eye regulation ability in patients with presbyopia complicated with visual fatigue of liver depression and spleen deficiency, and the effect is better than esculin and digitalis glycosides eye drops alone.

Dysfunctional lens syndrome: a prospective review / Síndrome do cristalino disfuncional: uma revisão prospectiva

ABSTRACT The term dysfunctional lens syndrome has gained acceptance in the field and encompasses natural changes due to aging of crystalline lens. The evolution of diagnostic devices has been a key factor in better staging, understanding and characterizing of these degenerative changes. Even with these technological advances and the use of subjective classifications, such as the classic Lens Opacities Classification System, an objective staging of early dysfunctional lens syndrome has yet to be established. Ocular wavefront aberrometry and objective scatter index, associated with Scheimpflug backscatter densitometry, have proven instrumental in detecting early dysfunctional lens syndrome. Staging of early dysfunctional lens syndrome has been proposed in the literature, but no classification has been recognized worldwide. The purpose of this literature review is to assess the current state of dysfunctional lens syndrome from a technological perspective and propose a new staging system to assist surgeons in making surgical decisions.

RESUMO O termo "síndrome disfuncional do cristalino" tem sido mais aceito na área e engloba mudanças naturais devido ao envelhecimento do cristalino. A evolução dos dispositivos diagnósticos tem sido fator fundamental para melhor estadiamento, compreensão e caracterização dessas alterações. Mesmo com esses avanços tecnológicos e o uso de classificações subjetivas, como o Lens Opacities Classification System , um estadiamento objetivo da síndrome disfuncional do cristalino precoce ainda não foi estabelecido. A aberrometria ocular total e o índice de superfície ocular, associado à densitometria de Scheimpflug, mostraram-se instrumentais na detecção da síndrome disfuncional do cristalino precoce. Embora estadiamentos precoces de síndrome disfuncional do cristalino tenham sido propostos na literatura, nenhum foi reconhecido mundialmente até o momento. O objetivo desta revisão de literatura é avaliar o estado atual da síndrome disfuncional do cristalino a partir de uma perspectiva tecnológica, e propor um novo sistema de estadiamento para auxiliar os cirurgiões na tomada de decisões cirúrgicas.

Analysis of the characteristics of electronic equipment usage distance for common users / 国际眼科杂志(Guoji Yanke Zazhi)

@#AIM: To analyse and characterize the pattern of working and mobile phone usage distances(MPUD)for common users of electronic devices and computers.<p>METHODS: Transversal descriptive study consisting of a screening campaign evaluating the visual status of different professionals working with computers or electronic devices more than 2h per day. A total of 100 healthy patients with a mean age of 41.2(range: 20-62)years were revised and subdivided according to job subgroups. A battery of screening tests was performed to all participants in a single session at the working environment of each of them, including measurement of the working distance(WD), arm length, and MPUD.<p>RESULTS:The WD was significantly longer than MPUD(61.22±12.35 <i>vs</i> 32.22±6.35 cm; <i>P</i><0.001). Likewise, MPUD was significantly shorter than the arm length(74.44±4.65 cm; <i>P</i><0.001). A total of 4%(4/100)and 91%(91/100)of patients had a WD and MPUD of 40 cm or below, respectively. A weak although statistically significant correlation was found between WD and MPUD(<i>r</i>=0.387, <i>P</i><0.001)as well as between WD and arm length(<i>r</i>=0.260, <i>P</i>=0.009). Statistically significant differences were detected among job subgroups in WD(<i>P</i>=0.021), being longer for militaries compared to university researchers and lecturers(<i>P</i>=0.025).<p>CONCLUSION:Working and mobile phone usage distances vary significantly among common users of computers and digital devices, although the use of mobile phones tends to be performed at significantly closer distances. This parameter should be considered when planning any type of optical correction, especially for presbyopia.

Satisfação de pacientes submetidos à cirurgia refrativa de PresbiLASIK / Satisfaction of patients submitted to PresbyLASIK refractive surgery

Resumo Objetivos: Avaliar a satisfação dos pacientes submetidos à cirurgia de Presbilasik central e determinar a prevalência de sintomas relatados após a cirurgia. Métodos: Este é um estudo descritivo, observacional, transversal, com dados obtidos de pacientes submetidos previamente ao PresbiLASIK. Resultados: A amostra consistiu de 45 pacientes, com média de idade de 57,7 (±7,19) anos. A nota média atribuída para a satisfação visual com o procedimento foi 8.9 (±1.0). A qualidade visual após a cirurgia foi classificada como igual ou melhor que a esperada por 84,5% dos pacientes e 31% apresentaram sintomas noturnos, como halos e raios de cometa. Conclusão: A qualidade de visão após o procedimento de PresbiLASIK foi altamente satisfatória para os pacientes. Fator determinante dessa satisfação é o processo de manejo das expectativas pré-operatórias dos pacientes, informando das possibilidades terapêuticas disponíveis, e, no caso da escolha cirúrgica, acerca das vantagens e limitações.

Abstract Objectives: Toassess the satisfaction of patients undergoing central Presbilasik surgery and to determine the age of patients who undergo PresbiLASIK and the prevalence of symptoms reported after surgery. Methods: This is a descriptive, observational, cross-sectional study with data collected from patients previously submitted to PresbiLASIK. Results: The sample consisted of 45 patients, with a mean age of 57.7 (±7,19) years. The average score attributed to visual satisfaction with the procedure was 8.9 (±1.0). Visual quality after surgery was classified as equal to or better than expected by 84.5% of the patients and 31% complained of nocturnal symptoms such as halos and comet rays. Conclusion: The quality of vision after the PresbiLASIK procedure was highly satisfactory for the patients. A determining factor for this satisfaction is the process of managing patients' preoperative expectations, informing them about the therapeutic possibilities available, and, in the case of surgical choice, about its advantages and limitations.

Clinical experience after tetrafocal intraocular lens implantation "PANOPTIX" / Experiência clínica após implantação de lentes intraoculares tetrafocais "PANOPTIX"

Abstract Purpose: To assess long, intermediate and near uncorrected visual acuity after a tetrafocal diffractive intraocular lens implantation, presence of dystopic phenomenon and patient satisfaction after surgery. Methods: Retrospective, observational study performed in Puerta de Hierro Specialties Hospital, in Jalisco, México. That included 100 eyes after phacoemulsification surgery by femtosecond assistance, followed by tetrafocal diffractive intraocular lens implantation due to cataract. Long, intermediate and near visual acuity without correction was measured, and presence or absence of dystopic phenomenon, plus patient satisfaction after surgery. Results: A total of 100 eyes in 50 patients who underwent cataract surgery with phacoemulsification by femtosecond assistance were evaluated. 100% underwent bilateral phacoemulsification. Long, intermediate, and near visual acuity after three months was in the most patients 20/20 (46%), 20/15 (44%) and Jaeger 1 (48%) respectively. The percentage or patients who refers halos was 7%; and other associated symptoms in 18%, being astenopia the most prevalent. The removal of the lens was not required in any case. Conclusion: Tetrafocal diffractive intraocular lenses provides excellent intermediate vision (at 60 centimeters) and satisfactory near (30 centimeters) and long (6 meters) visual acuity.

Resumo Objetivo: Avaliar a acuidade visual de longe, intermediária e de perto após o implante de lente intra-ocular difrativa tetrafocal, presença de fenômenos distópicos e satisfação do paciente após a cirurgia. Métodos: Estudo retrospectivo, observacional, realizado em Puerta de Hierro Hospital de Especialidades, em Jalisco, México. Isso incluiu 100 olhos após a cirurgia de facoemulsificação pela presença de laser de femtosegundo, seguida por implante de lente intra-ocular difrativa tetrafocal devido à catarata ou cirurgia facorrefractiva. Foi medida a acuidade visual de longe, intermediária e de perto, e a presença ou ausência de fenômenos distópicos, além da satisfação do paciente após a cirurgia. Resultados: Um total de 100 olhos em 50 pacientes submetidos à cirurgia de catarata com facoemulsificação por femtosegundo foram avaliados. 100% foram submetidos a facoemulsificação bilateral. A acuidade visual para longe, intermediária e de perto após três meses foi na maioria dos pacientes 20/20 (46%), 20/15 (44%) e Jaeger 1 (48%) respectivamente. A porcentagem ou pacientes que se referem a halos foi de 7%; e outros sintomas associados em 18%, sendo a astenopia a mais prevalente. A remoção da lente não foi necessária em nenhum caso. Conclusão: A lente intra-ocular difrativa tetrafocal fornece excelente visão intermediária (a 60 centímetros) e acuidade visual satisfatória de perto a (30 centímetros) e de longe (6 metros).

Research progress and clinical application of the new presbyopia-correcting intraocular lens / 国际眼科杂志(Guoji Yanke Zazhi)

@#Cataract surgery has become a refractive surgery, which has attracted much attention on postoperative functional vision and visual quality, and promoted the continuous development and improvement of intraocular lens(IOL)materials and design. The traditional presbyopia-correcting IOL has achieved distance and near visual acuity initially, while in recent years the new presbyopia-correcting IOL has further improved the visual experience of patients. This article reviews the progress to provide reference for clinical practice.

Multisectorial changes in the ciliary muscle during accommodation measured with high-resolution optical coherence tomography / Alterações multissetoriais no músculo ciliar durante a acomodação com uma tomografía de coerência óptica de alta resolução

ABSTRACT Purpose: To measure changes in the anterior ciliary muscle during accommodation at the nasal, superior, temporal, and inferior sectors by means of an anterior chamber optical coherence tomographer, and correlate them with vergence changes. Methods: Twenty-four subjects with healthy, phakic eyes, whose mean age was 27.1 ± 8.9 years, underwent measurement with an anterior chamber optical coherence tomographer. The anterior ciliary muscle was measured at the nasal, temporal, superior, and inferior sectors for 0, -1, -2, and -3 D of vergence. A linear model was used to assess the correlation of each eye parameter with the accommodative demand. Results: The anterior ciliary muscle area significantly increased with accommodation for each sector, with a maximum increase of about 30% for the nasal-temporal sectors and about 25% for the inferior-temporal sectors. The linear model showed a tendency toward a positive relationship between change in the ciliary muscle area of each sector and vergence. Conclusion: The anterior ciliary muscle area tends to increase with accommodation, although the increase has been shown to be symmetric between the pair sectors superior-nasal and inferior-temporal. These results may help to increase understanding of accommodation biometry and biomechanics.

RESUMO Objetivo: Medir as alterações do músculo ciliar anterior durante a acomodação nos setores nasal, superior, temporal e inferior, através de um tomógrafo de coerência óptica de câmara anterior, e correlacioná-las com alterações de vergência. Métodos: Vinte e quatro indivíduos com olhos saudáveis e fácicos, com idade média de 27,1 ± 8,9 anos, foram submetidos à medida com um tomógrafo de coerência óptica de câmara anterior. O músculo ciliar anterior foi medido nos setores nasal, temporal, superior e inferior para 0, -1, -2 e -3D de vergência. Um modelo linear foi utilizado para avaliar a correlação de cada parâmetro do olho com a demanda acomodativa. Resultados: A área do músculo ciliar anterior aumentou significativamente com a acomodação em cada setor, com um aumento máximo foi de cerca de 30% para os setores naso-temporais, e cerca de 25% para os inferiores-temporais. O modelo linear mostrou uma tendência para uma relação positiva entre a alteração da área do músculo ciliar de cada setor e a vergência. Conclusão: A área do músculo ciliar anterior tende a aumentar com a acomodação, embora o aumento tenha se mostrado simétrico entre os setores superior-nasal e inferior-temporal. Estes resultados podem ajudar a aumentar a compreensão da biometria e biomecânica da acomodação.

Prevalence of refractive errors, uncorrected refractive error, and presbyopia in adults in India: A systematic review

Purpose: The objective of this review is to estimate the prevalence of refractive errors, uncorrected refractive error (URE), and uncorrected presbyopia in adults aged ?30 years in India. Methods: The Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines were followed. A detailed literature search was performed to include all studies published from India from the year 1990 using the Cochrane Library, Medline, and Embase. Refractive error was defined by >0.50 D ametropia. URE was defined by presenting visual acuity (PVA) worse than 6/18 improving with pinhole or spectacle correction, and uncorrected presbyopia by near vision Results: Fifteen studies were included from South India, one each from Western and Central India, and one study covered 15 states across India. The prevalence of RE of at least 0.50 D of spherical equivalent ametropia was 53.1% [(95% confidence interval (CI): 37.2–68.5), of which myopia and hyperopia was 27.7% and 22.9%, respectively. The prevalence of URE was 10.2% (95% CI: 6.9–14.8), but heterogeneity in these estimates was very high. The prevalence of uncorrected presbyopia was 33% (95% CI: 19.1–51.0). Conclusion: This review highlights the magnitude of refractive errors among adults in India. More studies are needed using standard methods in regions where there is a lack of information on UREs. Programs delivering spectacles for adults in India will need to primarily focus on reading glasses to correct presbyopia along with spectacles for hyperopia and myopia.

Premature Presbyopia and its Risk Factors - A Hospital based Study

Introduction: Presbyopia, a physiological insufficiency ofaccommodation, impairs the ability to perform near task.Considered as a disease of the forties, it reduces functionalefficiency of the individual as well as the society since itaffects the majority of working population. This study was aneffort to evaluate the risk factors that can lead to its earlieronset. Purpose of the study was to evaluate the frequencyof risk factors associated with premature presbyopia in ahospital-based study in Sundergarh district, Odisha.Material and Methods: It was a hospital-based study carriedout at Hi-Tech Medical College and Hospital, Rourkela fromOctober 2016 to October 2018. Patients aged 30 years or morewho presented with difficulties in near work were includedin the study. Premature presbyopic was defined as presbyopicperson aged less than 40 years. Premature presbyopics werefurther subjected to a questionnaire and detailed examinationafter taking informed consent.Results: The mean age of presentation in prematurepresbyopics was 36.2 years and the average correction requiredwas 1.22 D. Among the total number of persons presentingwith presbyopia about one-eighth (12.03%) presented before40 years. Female sex, occupation requiring near work,exposure to sunlight for longer duration and hypermetropiawere most common risk factors over all. Among malessmoking, alcohol, exposure to higher temperature (factoryworkers) were significant risk factors. Multiparity, anemia andpremature menopause presented as important risk factors infemales. Smart phone usage was found to be an important riskfactor in urban population.Conclusion: Early presentation of presbyopia reducesthe functional efficiency of the individual. Evaluation ofrisk factors will help to determine the population at risk ofpremature presbyopia and their prompt management can bedone with near correction

Clinical Profile and Etiology of Neonatal Seizures in a Tertiary Care Hospital in North India

Introduction: Presbyopia, a physiological insufficiency ofaccommodation, impairs the ability to perform near task.Considered as a disease of the forties, it reduces functionalefficiency of the individual as well as the society since itaffects the majority of working population. This study was aneffort to evaluate the risk factors that can lead to its earlieronset. Purpose of the study was to evaluate the frequencyof risk factors associated with premature presbyopia in ahospital-based study in Sundergarh district, Odisha.Material and Methods: It was a hospital-based study carriedout at Hi-Tech Medical College and Hospital, Rourkela fromOctober 2016 to October 2018. Patients aged 30 years or morewho presented with difficulties in near work were includedin the study. Premature presbyopic was defined as presbyopicperson aged less than 40 years. Premature presbyopics werefurther subjected to a questionnaire and detailed examinationafter taking informed consent.Results: The mean age of presentation in prematurepresbyopics was 36.2 years and the average correction requiredwas 1.22 D. Among the total number of persons presentingwith presbyopia about one-eighth (12.03%) presented before40 years. Female sex, occupation requiring near work,exposure to sunlight for longer duration and hypermetropiawere most common risk factors over all. Among malessmoking, alcohol, exposure to higher temperature (factoryworkers) were significant risk factors. Multiparity, anemia andpremature menopause presented as important risk factors infemales. Smart phone usage was found to be an important riskfactor in urban population.Conclusion: Early presentation of presbyopia reducesthe functional efficiency of the individual. Evaluation ofrisk factors will help to determine the population at risk ofpremature presbyopia and their prompt management can bedone with near correction.

Influences of different reserved diopters during cataract extraction combined with TECNIS Symfony intraocular lens implantation on visual quality of presbyopia correction / 中华实验眼科杂志

Objective@#To compare the efficacy and visual quality of biocular cataract surgery combined with TECNIS Symfony intraocular lens(IOL) implantation in the correction of presbyopia with three different methods of reserved diopters.@*Methods@#A prospective cohort design was adopted.From October in 2016 to December in 2018, 120 patients 240 eyes with binocular cataract surgery implanted TECNIS Symfony IOL were divided into regular group, micro-near-vision group and micro-monovision group according to different reserved diopters, 40 patients 80 eyes in each group.The binocular IOL reserved diopter is + 0.10--0.20 D in regular group.The binocular IOL reserved diopter is -0.20--0.50 D in micro-near-vision group, meanwhile, the dominant eye reserved diopter is + 0.10--0.20 D, and the non-dominant eye reserved the myopia of -0.50--0.75 D in micro-monovision group.Defocus curves of single eye and binocular were measured and full distance visual acuity were analyzed 3 months after surgery.MTF values were detected by iTrace and compared between different groups.Visual function questionnaire of multifocal intraocular lenes (MIOLs)were analyzed and spectacle independence rate of presbyopia correction and disturbing photic phenomena were compared 3 months after surgery.This study protocol was approved by the ethics committee of Chongqing Aier Mega Eye Hospital, and this study followed the Declaration of Helsinki.@*Results@#Compared with regular group, the whole defocus curve of micro-near-vision group actually shifted to the right by 0.35 D, with almost no change in shape.The shape of the binocular defocus curve of micro-monovision group changed significantly compared with that of regular group, that is the wave peak became significantly wider, and the downward trend was more gentle.Spectacle independence rate of the three groups were all 100.00%, spectacle independence rate of intermediate distance in Micro-monovision group was 100.00%, which was higher than that of regular group(80.00%) and micro-near-vision group(90.00%), and the differences were statistically significant (χ2=37.04; P<0.01). The MTF value of the dominant eye was higher than that of the non-dominant eye in the Micro-monovision group, and the difference was statistically significant(t=3.74, P=0.001). There was no statistically significant difference in the occurrence rate of disturbing photic phenomena among the three groups(P>0.05).@*Conclusions@#Different reserved diopter design during cataract extraction combined with TECNIS Symfony IOL implantation suits different patients.Among the three different reserved diopters methods, the effect of micro-monovision method can obtain the highest spectacle independence rate, and provide satisfactory binocular far to near full-distance visual acuity.

Influences of different reserved diopters during cataract extraction combined with TECNIS Symfony intraocular lens implantation on visual quality of presbyopia correction / 中华实验眼科杂志

Objective To compare the efficacy and visual quality of biocular cataract surgery combined with TECNIS Symfony intraocular lens( IOL) implantation in the correction of presbyopia with three different methods of reserved diopters. Methods A prospective cohort design was adopted. From October in 2016 to December in 2018,120 patients 240 eyes with binocular cataract surgery implanted TECNIS Symfony IOL were divided into regular group,micro-near-vision group and micro-monovision group according to different reserved diopters,40 patients 80 eyes in each group. The binocular IOL reserved diopter is +0. 10--0. 20 D in regular group. The binocular IOL reserved diopter is -0. 20--0. 50 D in micro-near-vision group, meanwhile, the dominant eye reserved diopter is +0. 10--0. 20 D, and the non-dominant eye reserved the myopia of -0. 50--0. 75 D in micro-monovision group. Defocus curves of single eye and binocular were measured and full distance visual acuity were analyzed 3 months after surgery. MTF values were detected by iTrace and compared between different groups. Visual function questionnaire of multifocal intraocular lenes ( MIOLs ) were analyzed and spectacle independence rate of presbyopia correction and disturbing photic phenomena were compared 3 months after surgery. This study protocol was approved by the ethics committee of Chongqing Aier Mega Eye Hospital, and this study followed the Declaration of Helsinki. Results Compared with regular group, the whole defocus curve of micro-near-vision group actually shifted to the right by 0. 35 D,with almost no change in shape. The shape of the binocular defocus curve of micro-monovision group changed significantly compared with that of regular group,that is the wave peak became significantly wider,and the downward trend was more gentle. Spectacle independence rate of the three groups were all 100. 00％, spectacle independence rate of intermediate distance in Micro-monovision group was 100. 00％, which was higher than that of regular group (80. 00％) and micro-near-vision group(90. 00％),and the differences were statistically significant (χ2=37. 04;P<0. 01). The MTF value of the dominant eye was higher than that of the non-dominant eye in the Micro-monovision group,and the difference was statistically significant(t=3. 74,P=0. 001). There was no statistically significant difference in the occurrence rate of disturbing photic phenomena among the three groups(P>0. 05). Conclusions Different reserved diopter design during cataract extraction combined with TECNIS Symfony IOL implantation suits different patients. Among the three different reserved diopters methods, the effect of micro-monovision method can obtain the highest spectacle independence rate, and provide satisfactory binocular far to near full-distance visual acuity.

What is presbyopia?

Presbyopia is an aging eye. All parts of our body may lose their function with aging. The representative aging diseases in the field of ophthalmology are cataract and macular degeneration. Presbyopia is also a natural aging phenomenon that people has difficulty in focusing on near subject. There is a structure called lens in our eye and the function of lens is a refraction of lignt. Lens helps us focusing an object that we want to see with changing its thickness. When we try to focus on near subjects, ciliary muscle contracts to release the lens zonule and the lens becomes thicker. When we try to see far subjects, ciliary muscle relaxes and lens becomes thinner. These changes of lens thickness occurs very fast in young people, but with aging, the speed of changing the thickness of lens becomes slow. Finally, aged people can't change the lens thickness and can't focus on near subject without the help of near glasses and so on. In this case, we call it presbyopia.