DOCSLIB.ORG

Accuracy of Intraocular Lens Power Calculations Using the Zeiss Iol Master

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Accuracy of Intraocular Lens Power Calculations Using the Zeiss Iol Master ACCURACY OF INTRAOCULAR LENS POWER CALCULATIONS USING THE ZEISS IOL MASTER. A PROSPECTIVE STUDY VERHULST E.*, VRIJGHEM J.C.** ABSTRACT Conclusions Intraocular lens power calculations using the Zeiss Purpose IOL Master are easy to perform and result in excel- Partial Coherence Interferometry (PCI) is a fast, non- lent refractive outcomes. A-scan biometry is still contact method to calculate lens implant power for needed in case of mature cataract. cataract surgery. It has been reported as a poten- tially more accurate method than ultrasound bio- metry. RÉSUMÉ Prospective study of the refractive outcomes of a con- secutive series of patients undergoing phacoemul- Objet sification surgery with preoperative biometry by both Partial Coherence Interferometry (PCI) est une mé- ultrasound A-scan and PCI. thode rapide, non-contact, pour calculer la dioptrie Methods de l’implant lors de la chirurgie de la cataracte. Cette A series of 50 eyes of 35 patients underwent small- méthode serait plus fiable que la biométrie aux ul- incision phacoemulsification cataract surgery and trasons. lens implantation by one single surgeon. All patients Etude prospective des résultats réfractifs d’une sé- had preoperative biometry performed by both ultra- rie consécutive de patients qui subissent une chi- sound using the Sonomed and IOL Master optical rurgie de la cataracte. La biométrie pré-opératoire a biometry. The IOL Master results were included in été faite aux ultrasons A-scan et au PCI. the SRK II formula to calculate the lens implant pow- Méthodes er. Postoperative refractive assessment was per- formed 4 weeks after surgery. 50 yeux de 35 patients ont subi la chirurgie de la cataracte par phaco-émulsification avec implanta- Results tion de lentille intra-oculaire. Les interventions ont The mean difference in axial length between ultra- été exécutées par un seul chirurgien. Chez tous les sound and optical biometry was 0.2 mm. The IOL patients la biométrie pré-opératoire a été faite aux Master measures a longer axial length. The mean ultrasons en utilisant le Sonomed et à l’interférométrie keratometric power using the Javal instrument was en utilisant le IOL Master. Les résultats du IOL Mas- 43.4D and for the Zeiss IOL Master it was 42.9D. ter ont été incorporés dans la formule SRK II afin de At the week 4 postsurgery assessment, the overall calculer la valeur dioptrique de l’implant. La réfrac- refractive outcome was in the range of ±1D. Five tion postopératoire a été déterminée après 4 se- patients were unable to undergo PCI biometry due maines. to the density of cataract. Résultats La différence moyenne de la longueur axiale entre zzzzzz la biométrie aux ultrasons et au PCI était de 0.2 mm. Le IOL Master mesure une longueur axiale plus longue. * Department of Ophthalmology La valeur kératometrique moyenne du Javal était de University of Leuven, Belgium ** Department of Ophthalmology 43.4D comparée à une valeur moyenne du IOL mas- St Jean Hospital, Brussels, Belgium ter de 42.9D. La réfraction postopératoire après 4 semaines chez tous les patients se situait entre ±1D. received: 06.04.01 La biométrie au PCI était impossible chez 5 patients accepted: 30.06.01 à cause de la densité de la cataracte. Bull. Soc. belge Ophtalmol., 281, 61-65, 2001. 61 Conclusion INTRODUCTION: Le calcul de la valeur dioptrique de l’implant par le Zeiss IOL Master est facile à faire et donne des ré- EMMETROPIA IS THE sultats réfractifs excellents. A-scan biométrie reste GOAL nécessaire en cas de cataracte mature. Cataract extraction and artificial intraocular lens (IOL) implantation is one of the most frequent- SAMENVATTING ly and successfully ophthalmic surgical proce- Onderwerp dures carried out today. One of the remaining Partial Coherence Interferometry (PCI) is een snel- problems, however, is accurate calculation of le, non-contact methode om de dioptrie van het lens- IOL power, in order to obtain the desired post- implant bij cataract chirurgie te bepalen. Deze me- operative refraction. thode is mogelijks nauwkeuriger dan echografische While techniques in cataract surgery are con- biometrie. stantly improving, the demand of patients and Prospectieve studie van de refractieve resultaten na phacoemulsificatie bij een serie opeenvolgende pa- surgeons for a high predictability in the refrac- tienten waarbij de preoperatieve biometrie gebeur- tive result increases dramatically. de met A-scan echografie en met PCI. At a time where multifocal foldable lenses could be the future, a precise calculation of the po- Methode wer of intraocular lenses becomes even more Bij 50 ogen van 35 patienten werd phacoemulsifi- critical. catie met lensimplant uitgevoerd door één chirurg. The data required for accurate intraocular lens Bij alle patienten werd de pre-operatieve biometrie calculations include axial length, corneal cur- bepaald door middel van de Sonomed echograaf én vature and anterior chamber depth. These data de IOL Master interferometer. De waarden van de IOL Master werden gebruikt in de SRK II formule om de are integrated in calculation formula’s. The most dioptrie van het lensimplant te bepalen. De post- commonly used are the SRK II, SRK-T and Hol- operatieve refractie werd bepaald 4 weken na de in- laday formula. greep. In ultrasound biometry (1) measurements of Resultaten axial length can be obtained either by an ap- Het gemiddelde verschil in aslengte tussen A-scan planation or an immersion technique. With the echografie en optische biometrie bedroeg 0.2 mm. applanation technique, the sterile probe is di- De IOL Master meet een langere aslengte. De ge- rectly placed on the locally anaesthetized eye. middelde keratometrie waarde bedroeg 43.4D bij de Javal en 42.9D bij de Zeiss IOL Master. De postope- With the immersion technique, the probe is ratieve refractie na 4 weken lag voor alle patienten coupled to the eye using a medium of methyl- tussen ±1D. Bij 5 patienten was het onmogelijk om cellulose or water. The resolution in axial length PCI biometrie uit te voeren wegens de densiteit van measurements is about 0.1 mm, correspond- de cataract. ing to a mean postoperative error of 0.25 D. When considering the SRK II formula:P= Conclusie (A+C) - 2.5AL - 0.9K it is obvious that axial Bepaling van de intraoculaire lens sterkte door mid- length is the biggest source of error in IOL po- del van de Zeiss IOL Master is eenvoudig uit te voe- wer calculations (4). Immersion scans are more ren en geeft uitstekende refractieve resultaten. A-scan biometrie blijft nodig in geval van matuur cataract. precise because there is no corneal indenta- tion. Furthermore, ultrasound does not always KEY-WORDS measure the optical axis. Keratometry is the second most important parameter leading to Partial coherence interferometry, ultrasound possible errors due to calibration and patient biometry fixation. Recently, optical biometry (2,3) techniques of- MOTS-CLÉS fer new possibilities. The technology of an in- Partial coherence interferometry, biométrie strument like the Zeiss IOL Master is based on aux ultrasons. laser interferometry with partial coherent light, often termed as partial coherence interfero- 62 metry (PCI). Some important features of the IOL path difference of twice the optical length (OL) Master are the fact that it is a non-contact mea- of the eye between the two beams reflected at surement with higher speed and higher accu- the cornea and the two beams reflected at the racy with a resolution going up to 0.01 mm. retina, respectively. If the coherence length of The measurement results are operator indepen- the laser is shorter than 2 OL, the wave fronts dent: the reproducibility is high. Axial length from the retina and the cornea do not inter- can be measured in phakic, pseudophakic and fere. However, if the two path differences 2d aphakic eyes. The IOL Master still gives re- and 2 OL equal each other, two of the four re- liable results in pseudophakic eyes, in eyes with flected beams will interfere. The interference silicone in the vitreous and in eyes with aster- pattern that results will be seen with a detec- oid hyalosis. tor. In principle, the eye length can be mea- sured by a shift of the interferometer plates. interferometer The diode laser emits infrared light with a wave laser diode length of 780 ηm. The time needed for mea- beamspitter surements is about 0.5 sec. The IOL Master dOLprovides a measuring range of 14 to 39 mm. SUBJECTS AND METHODS detector The purpose of the study was to compare IOL Fig. 1 Diagram of the laser interferometer for measuring power calculations using the IOL Master ver- the axial length of the eye. sus ultrasound biometry and standard kerato- d: plate spacing of the interferometer OL: optical length of the eye metry. In a prospective study, optical and applanation Light from a laser diode (Fig. 1) passes an in- ultrasound biometry were preoperatively per- terferometer that splits the beams into two par- formed on 50 cataractous eyes. We used the allel beams: a direct beam and a second beam optical biometry data given by the Zeiss IOL that is reflected once at both interferometer Master to calculate the desired IOL power with plates and hence is retarded by a path differ- the SRK II formula in order to obtain an em- ence of twice the plate spacing d. Both beams metropia or slight myopia. illuminate the eye through a beamsplitter. They In all patients the Allergan SI40 NB silicone serve as measuring beams as well as a fixation foldable intraocular lens (A-cte 118.0) was im- target. The two coaxial beams are reflected at planted through a self-sealing 2,5 mm tempo- both the cornea and the retina yielding four re- ral incision after phacoemulsification. All inter- flected beams.
Load more

Recommended publications
  • Hyperopia Hyperopia
    Hyperopia Hyperopia hyperopia hyperopia • Farsightedness, or hyperopia, • Farsightedness occurs if your eyeball is too as it is medically termed, is a short or the cornea has too little curvature, so vision condition in which distant objects are usually light entering your eye is not focused correctly. seen clearly, but close ones do • Its effect varies greatly, depending on the not come into proper focus. magnitude of hyperopia, the age of the individual, • Approximately 25% of the the status of the accommodative and general population is hyperopic (a person having hyperopia). convergence system, and the demands placed on the visual system. By Judith Lee and Gretchyn Bailey; reviewed by Dr. Vance Thompson; Flash illustration by Stephen Bagi 1. Cornea is too flap. hyperopia • In theory, hyperopia is the inability to focus and see the close objects clearly, but in practice many young hyperopics can compensate the weakness of their focusing ability by excessive use of the accommodation functions of their eyes. Hyperopia is a refractive error in • But older hyperopics are not as lucky as them. By which parallel rays of light aging, accommodation range diminishes and for 2. Axial is too short. entering the eye reach a focal older hyperopics seeing close objects becomes point behind the plane of the retina, while accommodation an impossible mission. is maintained in a state of relaxation. 1 Amplitude of Accommodation hyperopia Maximum Amplitude= 25-0.4(age) • An emmetropic eye for reading and other near Probable Amplitude= 18.5-.3(age) work, at distance of 16 in (40cm), the required amount of acc.
    [Show full text]
  • Defining Emmetropia and Ametropia As a Function of Ocular Biometry II
    SyntEyes: a Higher Order Statistical Eye Model for Healthy Eyes Jos J. Rozema,*† MSc PhD, Pablo Rodriguez,‡ MSc PhD, Rafael Navarro,‡ MSc PhD, Marie-José Tassignon*†, MD PhD *Dept. of Ophthalmology, Antwerp University Hospital, Edegem, Belgium † Dept. of Medicine and Health Sciences, Antwerp University, Wilrijk, Belgium ‡ICMA, Consejo Superior de Investigaciones Científicas-Universidad de Zaragoza, Facultad de Ciencias, Zaragoza, Spain Abstract Purpose: To present a stochastic eye model that simulates the higher order shape parameters of the eye, as well as their variability and mutual correlations. Methods: The biometry of 312 right eyes of 312 subjects were measured with an autorefractometer, a Scheimpflug camera, an optical biometer and a ray tracing aberrometer. The corneal shape parameters were exported as Zernike coefficients, which were converted into eigenvectors in order to reduce the dimensionality of the model. These remaining 18 parameters were modeled by fitting a sum of two multivariate Gaussians. Based on this fit an unlimited number of synthetic data sets (‘SyntEyes’) can be generated with the same distribution as the original data. After converting the eigenvectors back to the Zernike coefficients, the data may be introduced into ray tracing software. Results: The mean values of nearly all SyntEyes parameters was statistically equal to those of the original data (two one-side t test). The variability of the SyntEyes parameters was the same as for the original data for the most important shape parameters and intraocular distances, but showed significantly lower variability for the higher order shape parameters (F test) due to the eigenvector compression. The same was seen for the correlations between higher order shape parameters.
    [Show full text]
  • PRESBYOND Laser Blended Vision Practical Guide
    PRESBYOND Laser Blended Vision Practical Guide Disclaimer: This practical guide was produced independently by Dan Z Reinstein, MD MA(Cantab) FRCSC DABO FRCOphth FEBO1, 2, 3, 4 Glenn I Carp, MBBCh, FC Ophth (SA)1 Timothy J Archer, MA(Oxon), DipCompSci(Cantab)1, 4 Sharon Ritchie, BSc (Hons), MCOptom1 1 London Vision Clinic, London, UK 2 Department of Ophthalmology, Columbia University Medical Center, NY, USA 3 Centre Hospitalier National d’Ophtalmologie, Paris, France 4 Biomedical Science Research Institute, University of Ulster, Coleraine, Northern Ireland Financial Disclosure: Dr Reinstein is a consultant for Carl Zeiss Meditec (Carl Zeiss Meditec AG, Jena, Germany) and has a proprietary interest in the Artemis technology (ArcScan Inc, Golden, Colorado) through patents administered by the Center for Technology Licensing at Cornell University (CTL), Ithaca, New York. Dr Carp receives travel expenses from Carl Zeiss Meditec. The remaining authors have no proprietary or financial interest in the materials presented herein. Preoperative 1. Pre-operative testing protocol 2. Manifest refraction 3. Dominance testing 4. Laser Blended Vision tolerance assessment 5. What myopic target to expect 6. Laser Blended Vision explanation and patient counselling Postoperative 7. Postoperative evaluation 8. Postoperative visual course 9. Cross-blur management at final outcome 10. Appendix A – Preoperative tolerance test examples 11. Appendix B – Postoperative cross-blur and enhancement examples 2 1. Pre-operative testing protocol Highlighted topics are particularly relevant for PRESBYOND • History. Motivation for surgery, previous ocular • Cirrus OCT corneal and epithelial pachymetry. history (including detailed history of contact lens wear, • Undilated WASCA aberrometry. period of wear, type of lens, wear modality, last worn, • Ocular Response Analyser.
    [Show full text]
  • Posterior Vitreous Detachment As Observed by Wide-Angle OCT Imaging
    Posterior Vitreous Detachment as Observed by Wide-Angle OCT Imaging Mayuka Tsukahara, OD,1,* Keiko Mori, MD,1 Peter L. Gehlbach, MD, PhD,2 Keisuke Mori, MD, PhD1,3,4,* Purpose: Posterior vitreous detachment (PVD) plays an important role in vitreoretinal interface disorders. Historically, observations of PVD using OCT have been limited to the macular region. The purpose of this study is to image the wide-angle vitreoretinal interface after PVD in normal subjects using montaged OCT images. Design: An observational cross-sectional study. Participants: A total of 144 healthy eyes of 98 normal subjects aged 21 to 95 years (51.4Æ22.0 [mean Æ standard deviation]). Methods: Montaged images of horizontal and vertical OCT scans through the fovea were obtained in each subject. Main Outcome Measures: Montaged OCT images. Results: By using wide-angle OCT, we imaged the vitreoretinal interface from the macula to the periphery. PVD was classified into 5 stages: stage 0, no PVD (2 eyes, both aged 21 years); stage 1, peripheral PVD limited to paramacular to peripheral zones (88 eyes, mean age 38.9Æ16.2 years, mean Æ standard deviation); stage 2, perifoveal PVD extending to the periphery (12 eyes, mean age 67.9Æ8.4 years); stage 3, peripapillary PVD with persistent vitreopapillary adhesion alone (7 eyes, mean age 70.9Æ11.9 years); stage 4, complete PVD (35 eyes, mean age 75.1Æ10.1 years). All stage 1 PVDs (100%) were observed in the paramacular to peripheral region where the vitreous gel adheres directly to the cortical vitreous and retinal surface. After progression to stage 2 PVD, the area of PVD extends posteriorly to the perifovea and anteriorly to the periphery.
    [Show full text]
  • Distance Vision, Near Vision and Quality of Life Between Preferred Emmetropia and Residual Myopia in Monofocal Intraocular Lens Implantation - a Comparative Study
    10-Comparative00212_3-PRIMARY.qxd 5/13/21 10:29 PM Page 340 ORIGINAL ARTICLE Distance vision, near vision and quality of life between preferred emmetropia and residual myopia in monofocal intraocular lens implantation - A Comparative study Jaafar Juanarita, MMed 1,2,3 , Abdul Rahman Siti-Khadijah, MBBS 1,2 , Bakiah Shaharuddin, PhD 4, Yaakub Azhany, MMed 1,2 1Department of Ophthalmology and Visual Sciences, School of Medical Sciences, Universiti Sains Malaysia, Kubang Kerian, Kelantan, Malaysia, 2Ophthalmology Clinic, Hospital Universiti Sains Malaysia, Kubang Kerian, Kelantan, Malaysia, 3Hospital Sultanah Bahiyah, Alor Setar, Alor Setar, Kedah, 4Advanced Medical and Dental Institute, Universiti Sains Malaysia, Kepala Batas, Penang, Malaysia unoperated cataracts. 2 Currently, there is no effective ABSTRACT prevention for cataracts, and the only treatment is to remove Introduction: This study was done to evaluate the visual the cloudy lens. 3 acuity and quality of life in predicted emmetropia (EM) and predicted residual myopia (RM) patients following Intraocular lens (IOL) implantation is the commonest phacoemulsification with monofocal intraocular lens practice of visual rehabilitation after cataract surgery. implantation. Monofocal or fixed focal IOLs have only one focus at distance; thus, the placement of a monofocal IOL requires Materials and Methods: This prospective comparative study corrective lenses (spectacles) after surgery for near vision- was conducted in the ophthalmology clinic of the Universiti related tasks. Although no statistical difference was found Sains Malaysia Hospital, Kelantan, Malaysia. Overall, 139 between multifocal (MFIOL) and monofocal IOL with respect patients with senile cataract were randomised into EM and to achieving a post-operative best-corrected visual acuity RM groups. At three months post-operatively, patients were (BCVA) of 6/6, near vision was often found to be better with assessed for distance and near vision, as well as quality of MFIOL.
    [Show full text]
  • Chapter 14 Presbyopia Correction
    Chapter 14 Presbyopia Correction Introduction ....................................................................................208 Nonsurgical Methods for Correction of Presbyopia............209 Surgical Methods for Correction of Presbyopia ...................210 Laser Assisted Presbyopia Corrections25,26 ........................................................216 Conclusion .......................................................................................217 14. Presbyopia Correction Pulak Agarwal, Chirakshi Dhull, Yogita Gupta, and Sudarshan Khokhar Introduction (AP). Thus, it proposes loss of lens capsule elasticity as the main cause of loss of accommodation. Loss of accommodative amplitude due to aging is known as presbyopia. Symptoms include diminution of vision for near Schachar Theory3 sight, headache, asthenopia, and eye strain. Many plausible mechanisms in the form of theories have It proposes that during ciliary contraction, the tension in been proposed for accommodation (Fig. 14.1), equatorial zonular fibers increases, which leads to steepen- ing of anterior lens capsule. With aging, the distance between Helmholtz Theory1,2 ciliary body and the equatorial lens capsule decreases, which causes ineffective tension generation. Most of the scleral- It proposes that when the ciliary body is relaxed, the based interventions are based on this theory. zonules are stretched, which lead to flattening of anterior lens capsule and decrease in the diameter (AP) of the lens. Catenary Theory As opposed to when the ciliary body contracts,
    [Show full text]
  • Immersion A-Scan Compared with Partial Coherence Interferometry Outcomes Analysis
    Immersion A-scan compared with partial coherence interferometry Outcomes analysis Mark Packer, MD, I. Howard Fine, MD, Richard S. Hoffman, MD, Peggy G. Coffman, COT, Laurie K. Brown, COMT, COE ABSTRACT Purpose: To compare 2 methods of axial length measurement, immersion ultrasonogra- phy and partial coherence interferometry, and to elucidate surgical outcomes based on immersion measurements. Setting: Oregon Eye Institute, Eugene, Oregon, USA. Methods: Axial length measurements in 50 cataractous eyes were obtained by optical biometry (IOLMasterா, Zeiss Humphrey Systems) and immersion ultrasound (Axis II, Quantel Medical), and the results were compared. Intraocular lens (IOL) power calcu- lations in the same eyes after cataract extraction and posterior chamber IOL implanta- tion were evaluated retrospectively based on the postoperative spherical equivalent prediction error. Results: Immersion ultrasonography and partial coherence interferometry measurements correlated in a highly positive manner (correlation coefficient ϭ 0.996). Outcomes analysis demonstrated 92.0% of eyes were within Ϯ0.5 diopter of emmetropia based on immersion axial length measurements. Conclusion: Immersion ultrasonography provided highly accurate axial length measure- ments and permitted highly accurate IOL power calculations. J Cataract Refract Surg 2002; 28:239–242 © 2002 ASCRS and ESCRS xial length measurement remains an indispensable mersion technique.2 Reportedly “user-friendly” and less A technique for intraocular lens (IOL) power calcu- dependent on technician expertise than ultrasound lation. Recently, partial coherence interferometry has methods, noncontact optical biometry is, however, lim- emerged as a new modality for biometry.1 Postoperative ited by dense media, eg, posterior subcapsular cataract. results achieved with this modality have been considered A second limitation of the optical method is the lack of “analogous” to those achieved with the ultrasound im- a lens thickness measurement, a required variable in the Holladay 2 IOL power calculation software, version 2.30.9705.
    [Show full text]
  • Training Eye Instructions
    Training Eye Instructions Using the Direct Ophthalmoscope with the Model Eye The Model Eye uses a single plastic lens in place of the cornea and crystalline lens of the real eye (Fig. 20). The lens is mounted at one end of an open plastic tube into which another tube holding the “retina” is inserted. The model eye also has two different pupil sizes (2, and 4 mm in diameter) that are selected by moving the plastic pupil strip left or right. Taking the pupil strip out completely provides a pupil diameter of 8 mm. pupil strip outside tube convex lens velcro "retina" inside sliding tube Fig. 20. Cross-section of the Model Eye. Assembling the Model Eye Each Model Eye kit contains: Stand Outer tube that mounts on the stand Inner tube that slides into the outer tube Pupil strip 6 black plastic disks 5 images of retinas and 1 mm grid with double-stick tape on back 1 cross hair focus disk Attach the large, outer tube to the stand by pressing the black V-shaped plastic attached to the tube over the clear plastic ball on the stand. Next, insert the smaller-diameter inner tube into the Model Eye. EXPERIMENT 1: Emmetropia In a normal, emmetropic eye, parallel rays of light from a distant object come to focus on the retina (Fig. 21A). Light rays are “reversible”, that is they travel the same path whether going into or out of an optical system. Consequently, if the retina of an emmetropic eye could “light up”, light rays from a point on the retina would exit the eye as parallel rays (Fig.
    [Show full text]
  • Profile of Patients with Floaters in Saiful Anwar Hospital Malang
    International Journal of Retina (IJRETINA) 2018, Volume 1, Number 2. P-ISSN. 2614-8684, E-ISSN.2614-8536 PROFILE OF PATIENTS WITH FLOATERS IN SAIFUL ANWAR HOSPITAL MALANG Fenti Kusumawardhani Hidayah, Nadia Artha Dewi, Safaruddin Refa Department of Ophthalmology, Universitas Brawijaya, Malang, Indonesia ABSTRACT Introduction: To report the profile of patients with floaters as a subjective complain in Saiful Anwar Hospital from July 2012 until June 2013. Methods: an observasional descriptive study was conducted, collecting data on gender, age, subjective complain (floaters, flashes and subjective vision reduction), best corrected visual acuity and diagnose from patient’s medical record. Result: 169 patients (215 eyes) were included in this study. Female patients contributed a higher percentage than male with mean of age was 49 years old. The subjective complain was floaters (67%), floater with blurred vision (22%), floater with flashes (6%) and patients with floaters, flashes, and blurred vision was 5%. Myopia was the most common refraction problem. Diagnose recorded from this study were posterior vitreous detachment (PVD) (34%), no abnormalities (13%), PDR (10%), RRD (9%), peripheral retinal degeneration (14%) retinal break (6%), corpus vitreous degeneration (3%), vitreous haemorhage (3%), posterior uveitis (2%) and others (6%). Conclusion: The most common cause of floaters is PVD. Even it is usually a save condition but there are some condition with floater as a subjective complain which is threatening vision, so accurate eye examination from anterior to posterior segment were needed. Keywords: floaters, flashes, blurred vision, vitreoretinal pathology Cite This Article: HIDAYAH, fenti kusumawardhani; DEWI, nadia artha. Profile of Patients with Floaters in Saiful Anwar Hospital Malang.
    [Show full text]
  • Associations of Presbyopia with Vision-Targeted Health-Related Quality of Life
    CLINICAL SCIENCES Associations of Presbyopia With Vision-Targeted Health-Related Quality of Life Peter J. McDonnell, MD; Paul Lee, MD, JD; Karen Spritzer; Anne S. Lindblad, PhD; Ron D. Hays, PhD Objective: To evaluate the associations of presbyopia in 7 of 13 subscales (PϽ.05). In those aged 45 years or and its correction, particularly monovision optical cor- older, correction of presbyopia with monovision was as- rection, with vision-targeted health-related quality of life. sociated with statistically significantly better scores on 3 subscales (expectations, dependence on correction, and Methods: The National Eye Institute Refractive Error appearance) compared with single-vision correction. One Quality of Life (NEI-RQL) Instrument was prospec- subscale (dependence on correction) showed worsen- tively self-administered by subjects from 6 medical cen- ing scores with increasing age without adjustment for need ters in the following age and correction categories: sub- or type of correction. Older persons with monovision cor- jects with emmetropia younger than 45 years (n=75), rection had significantly worse scores than younger sub- subjects with emmetropia aged 45 years or older (n=38), jects with emmetropia on all subscales except subopti- and subjects with ametropia aged 45 years or older with- mal correction and appearance. out monovision (n=486) or corrected with monovision (n=38). Differences in the 13 NEI-RQL Instrument sub- Conclusions: Presbyopia is associated with worse vision- scale scores among subjects in the 4 groups were exam- targeted health-related quality of life compared with ined. The age of 45 years or older was used as a surro- younger subjects with emmetropia.
    [Show full text]
  • Thieme: Ophthalmology
    435 Refrakční vady a korekce 16.1 základní termíny Nekorigovaná a korigovaná zraková ostrost Minimum separabile- dán vzdáleností čípků 2,5um, zvětšuje se do periferie Je dán velikostí 1 minuty, což odpovídá asi 0,004mm na sítnici Refraction: Emmetropia and Ametropia Refraction is defined as the ratio of the refractive power of the lens and cornea (the refractive media) to the axial length of the globe. Emmetropia is distinguished from ametropia. Emetropie (Figs. 16. 2, 16.6a) Lang, Ophthalmology: A Pocket Textbook Atlas, 2nd Ed. (ISBN 978-1-58890-555-0), copyright © 2007 Thieme Medical Publishers. All rights reserved. Usage subject to terms and conditions of license. 436 16 Optics and Refractive Errors Resolution of the eye (minimum threshold resolution) Fig. 16.1 Two points (O and O ) can only be perceived as distinct if at least one un- 1 2 stimulated cone (z) lies between two stimulated cones (x and y) on the retina. Due to optical aberrations and diffraction, a punctiform object is reproduced as a circle (k). This results in a maximum resolution of the eye of 0.5–1 minutes of arc or 0.5/60– 1/60 of a degree. The drawing is not to scale. Focal point in emmetropia and ametropia Fig. 16.2 Parallel rays of light entering the eye from an optically infinite distance meet at a focal point on the retina in emmetropia (black lines). In hyperopia, this focal point (II) lies posterior to the retina (green lines). In myopia (I), it lies anterior to the retina (red lines). Ametropia (refrakční vada).
    [Show full text]
  • The Ebb and Flow of Presbyopic Correction
    The Ebb and Flow of Presbyopic Correction Dan Z Reinstein, MD, MA(Cantab), FRCSC, DABO, FRCOphth, FEBO1,2,3 Ryan S Vida, OD, FAAO1 Timothy J Archer, MA(Oxon), DipCompSci(Cantab), PhD1 1. London Vision Clinic, London UK 2. Columbia University Medical Center, New York, NY, USA 3. Sorbonne Université, Paris, France 4. Biomedical Science Research Institute, Ulster University, Coleraine, UK Financial Disclosure • The author (DZ Reinstein) is a consultant for Carl Zeiss Meditec AG (Jena, Germany) • The author (DZ Reinstein) acknowledges a financial interest in Insight 100 VHF digital ultrasound (ArcScan Inc, Golden, CO) ©DZ Reinstein 2019 [email protected] Presbyopic Correction: Cornea & Lens Multifocal Sph Ab EDoF Monovision ©DZ Reinstein 2019 [email protected] Trends in presbyopic correction Full multifocality Reduced Extended DoF + Reduced Full Monovision multifocality µ-anisometropia Monovision OD OS OD OS OD OS OD OS OD OS Distance Challenges Intermediate Monovision Maximise Range of Vision Improve SafetyTolerance & Poor Safety / Low Tolerance Low / Safety Poor Near ©DZ Reinstein 2019 [email protected] Trends in presbyopic correction: Multifocality Full multifocality Reduced Extended DoF + CornealReduced Full Monovision multifocality µ-anisometropia Monovision OD OS OD OS OD OS OD OS OD OS Distance “Multi-focality attempts to substitute the loss of a dynamic system (accommodation) with a static system (multiple foci Challenges in one eye)” Intermediate John Marshall, AECOS 2013 Monovision Maximise Range of Vision
    [Show full text]