• Title/Summary/Keyword: Intraocular lens

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A Study of Optical Properties of Intraocular Lenses and of Measurement of the Index of Reflection for an Unknown Liquid

  • Joo, Won Don;Jung, Mee Suk
    • Journal of the Optical Society of Korea
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    • v.16 no.3
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    • pp.236-242
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    • 2012
  • In general, such methods as interferometers or wavefront sensors are commonly used for testing of an optical system and optical components. In these cases, the surrounding environments are unlikely to affect the measurements. On the other hand, intraocular lenses of hydrophilic materials with special properties experience a certain difficulty in testing the optical properties. An intraocular lens is dried in the air, which causes deformation and changes the optical characteristics such as index of refraction and thickness. Thus, it is hard to measure the optical characteristics of an intraocular lens by using common methods. In this study, a special structure is used for measuring of the transmission wavefront aberration and effective focal length of an intraocular lens of hydrophilic materials by using a Shark-Hartmann sensor among the various measuring methods. As an application of this measuring method, this study shows a simple method to measure the index of refraction of unknown liquids with a plano-convex lens with a well known index of refraction. Also, this method is used to measure the optical properties of a plano-convex such as index of refraction and curvature by using a liquid with a well known index of refraction.

Development of Hydrogel for Decrease Protein Adsorption and Application to Intraocular Lens (단백질흡착 감소용 하이드로겔의 개발 및 인공수정체로의 적용)

  • Ko, Na Young;Lee, Hyun Mee
    • Journal of the Korean Chemical Society
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    • v.62 no.1
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    • pp.30-35
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    • 2018
  • The purpose of this study was to decrease the protein adsorption and improve the function of the hydrophobic acrylic Intraocular lens(IOL). Hydrophobic acrylic intraocular lenses were prepared by using ethyleneglycol phenyletheracrylate (EGPEA), styrene and 2-hydroxyethyl methacrylate (HEMA). Polyvinyl pyrrolidone (PVP) and 2-methacryloyloxyethyl phosphorylcholine (MPC) were used as additives. Water contents, wettability, light transmittance and protein adsorption amount were measured to evaluate the physical properties of the intraocular lens. The water content and wettability of all samples containing additives were increased and the amount of protein adsorption decreased. In particular, samples containing MPC showed a further decrease in protein adsorption. The hydrophobic acrylic intraocular lens with PVP and MPC was found to improve the function of the intraocular lens by reducing the protein adsorption while having basic physical properties.

The correction principle of Aphakia using the Intraocular Lens (안내렌즈를 이용안 무수정체안의 교정원리)

  • Kim, Bong-Hwan;Kim, Tae-Hyun;Lim, Hyeon-Seon;Ji, Taek-Sang;Ko, Jung-Why
    • Journal of Korean Ophthalmic Optics Society
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    • v.10 no.4
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    • pp.339-345
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    • 2005
  • In this paper, we studied the principle that correct the emmetropia to the aphakia using intraocular lens. At present, in an ophthalmic clinic, I.O.L which is using for correction of the vision clinically has presented how to prescribe more accurately by using optical method. To correct the Aphakia for the emmetropia, we considered that the basic cause of Ametropia was the refraction and the axial length. The correction principle is made equal to the Back Focal Length(BFL) and the vitreous length from lens to retina. For the confirmation of the correction principle, we used the Gullstrand number I eye model in emmetropia. For the myopia and hyperopia, we used the clinical data and replaced crystalline lens with intraocular lens.

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An Integrative Review on Alterations of Sleep after Cataract Surgery (백내장 수술 후 수면 변화에 관한 통합적 고찰)

  • An, Gyeong-Ju
    • Journal of Korean Biological Nursing Science
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    • v.21 no.1
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    • pp.12-21
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    • 2019
  • Purpose: The purpose of this study was to review previous literature with an aim to explore the sleep disturbance level after a patient undergoes cataract surgery using an integrative review. Methods: We used the key words, 'cataract surgery', 'sleep', and 'intraocular lens' to find peer-reviewed publications in seven databases. Among 450 searched articles, eight articles were selected after exclusion of articles that did not meet the criteria. Results: Five of the articles submitted that subjective sleep quality of the patients with blue-filtering intraocular lens (BF-IOL) implant improved as compared to that before surgery. The change of saliva melatonin concentration after BF-IOL implant did not coincide in two of the articles. Two of the articles reported an increased level of intrinsically photosensitive retinal ganglion cells response after BF-IOL implantation. Conclusion: The published studies stated that BF-IOL implant did not have any negative impact on quality of sleep among cataract patients suffering with poor sleep. Rregardless of intraocular lens type, cataract surgery may increase photoreception of intrinsically photosensitive retinal ganglion cells one year after surgery although the mechanism was not clear. It is necessary to identify various factors influencing the quality of sleep such as gender and activities among cataract patients with BF-IOL implant in the future.

Trifocal versus Bifocal Diffractive Intraocular Lens Implantation after Cataract Surgery or Refractive Lens Exchange: a Meta-analysis

  • Yoon, Chang Ho;Shin, In-Soo;Kim, Mee Kum
    • Journal of Korean Medical Science
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    • v.33 no.44
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    • pp.275.1-275.15
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    • 2018
  • Background: We compared the efficacy between trifocal and bifocal diffractive intraocular lens (IOL) implantation. Methods: Through PubMed, MEDLINE, EMBASE, and CENTRAL, we searched potentially relevant articles published from 1990 to 2018. Defocus curves, visual acuities (VAs) were measured as primary outcomes. Spectacle dependence, postoperative refraction, contrast sensitivity (CS), glare, and higher-order aberrations (HOAs) were measured as secondary outcomes. Effects were pooled using random-effects method. Results: We included 11 clinical trials, with a total of 787 eyes (395 subjects). The trifocal IOL group showed better binocular distance VA corrected with defocus levels of -0.5, -1.0, -1.5, and -2.5 diopter than the bifocal IOL group (All $P{\leq}0.004$). The trifocal IOL group showed better monocular uncorrected distance and intermediate VAs (mean difference [MD], -0.04 logarithm of the minimum angle of resolution [logMAR]; 95% confidence interval [CI], -0.07, -0.01; P = 0.006 and MD, -0.07 logMAR; 95% CI, -0.13, -0.01; P = 0.03, respectively). Postoperative refraction, glare, CS, and HOAs were not significantly different from each other. Conclusion: The overall findings indicate that trifocal diffractive IOL implantation is better than the bifocal diffractive IOL in intermediate VA, and provides similar or better in distance and near VAs without any major deterioration in the visual quality.

The Effect of Extracapsular Cataract Extraction and Posterior Chamber Lens Implantation on Intraocular Pressure (백내장적출술 및 인공수정체삽입술이 안압에 미치는 영향)

  • Cha, Soon-Cheol;Lee, Kyoo-Won
    • Journal of Yeungnam Medical Science
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    • v.11 no.2
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    • pp.277-283
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    • 1994
  • We studied the change in intraocular pressure (IOP) in 15 consecutive cataract patients who underwent extracapsular cataract extraction and posterior chamber lens implantation between Feb. 1993 and Apr. 1993 to evaluate the effect of this surgery on postoperative IOP. To evaluate the clinical usefulness of non-contact tonometer, the intraocular pressures were measured with Kowa non-contact tonometer (TM-2000, Japan) as well as Goldmann applanation tonometer. There was a decrease in IOP of $3.4{\pm}2.9$mmHg (p<0.00l) 3 months after this surgery and the intraocular pressure differences between pseudophakic eyes and contralateral phakic eyes at 3 months postoperatively were $2.4{\pm}3.8$mmHg (p<0.05). The correlation coefficient between non-contact tonometer and Goldmann tonometer was 0.8876 (p=0.001) in the postoperative 76 eyes. Therefore, our results suggest that extracapsular cataract extracion and posterior chamber lens implantation alone can be a useful surgical method in cataract patient with ocular hypertension, and non-contact tonometer was relatively accurate in measuring the postoperative intraocular pressure.

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Intraocular Lymphoma in a Dog (개의 Intraocular Lymphoma)

  • 우흥명
    • Journal of Veterinary Clinics
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    • v.18 no.4
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    • pp.429-433
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    • 2001
  • Lymphoma is one of the most common malignant neoplasms of the dog. Little has been published on intraocular lymphoma in dogs. This report presents a 8-year-old neutered male mixed dog with a previous history on inflammatory debris on the anterior and posterior lens capsules, vitreal hemorrhage, generalized peri-pheral lymphadenopathy and a palpable mid-abodominal mass. History, clinical signs, radiography, cytology, histopathology and chemotherapeutic response confirmed multicentric lymphoma with secondary ocular infla-mmation. Intraocular lymphoma, the most common secondary neoplasm of the canine eye, may be the present-ing evidence of systemic disease. This report describes a dog that presented with ocular manifestations of multicentric lymphoma.

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Clinical Efficacy of Bunny Multifocal Intraocular Lens after Cataract Surgery (버니 다초점인공수정체의 임상적 효용성)

  • Cho, Myung Ho;Park, Jae Yeong;Park, Byung Gun;Lee, Jong Soo
    • Journal of The Korean Ophthalmological Society
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    • v.59 no.12
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    • pp.1129-1136
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    • 2018
  • Purpose: To compare the postoperative clinical outcomes after cataract surgery and implantation using the BunnyLens $MF^{(R)}$ and $ReSTOR^{(R)}$ multifocal intraocular lenses. Methods: Sixty-five eyes implanted with multifocal intraocular lenses were divided into two groups involving either $ReSTOR^{(R)}$ (39 eyes) or BunnyLens $MF^{(R)}$ (26 eyes) lenses. In these two groups, the distant and near visual acuity, astigmatism, spherical equivalent, and contrast sensitivity test were examined at preoperative and postoperative 1 week, 8 weeks, and 24 weeks. We compared the clinical efficacy between the two groups before and after cataract surgery using statistical analysis. Results: The mean value of distant and near visual acuity, and spherical equivalent of both groups after intraocular lens implantation were significantly improved, compared with the preoperative values (p < 0.05), while there was no significant differences between the two groups (p > 0.05). The means of postoperative distant and near visual acuity, astigmatism, and contrast sensitivity test were not significantly different between $ReSTOR^{(R)}$ and BunnyLens $MF^{(R)}$ lenses (p > 0.05). The mean numeric error of spherical equivalent at the final postoperative 24 weeks was $-0.17{\pm}0.50$ diopters (D) for the $ReSTOR^{(R)}$ lenses and $-0.34{\pm}0.52D$ for the BunnyLens $MF^{(R)}$ lenses (p > 0.05). Conclusions: BunnyLens $MF^{(R)}$ and $ReSTOR^{(R)}$ lenses showed no significant difference in clinical efficacy, including distance and near vision, spherical equivalent error, and contrast sensitivity test after cataract surgery. However, it should be noted that BunnyLens $MF^{(R)}$ lenses had a tendency toward myopic shift compared with $ReSTOR^{(R)}$ lenses.

Rotational Stability of AcrySof Toric Intraocular Lens Over Time: Influence of Capsulorhexis Contraction

  • Kim, Joong Hee;Cho, Kyong Jin
    • Medical Lasers
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    • v.9 no.1
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    • pp.44-50
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    • 2020
  • Background and Objectives To evaluate the rotational stability of AcrySof toric intraocular lenses (IOL) by considering lapse of postoperative time and influence of capsulorhexis contraction. Materials and Methods A prospective, masked, single center study was conducted on 19 patients who had undergone microcoaxial cataract surgery and AcrySof toric IOL implantation. Slit-lamp retroillumination photographs of anterior segments were obtained from all patients after 1 week, 1 month and 3 months post-surgery. The degree of alteration of the postoperative IOL axis alignment and the amount of anterior capsular shrinkage were analyzed using Adobe Photoshop software. Results The mean degree of toric IOL axis misalignment was 2.18 (±20.2) degrees at 3 months follow-up. Quadrant analysis of the capsulorhexis aperture area at 1 week and 1 month post-operative, showed counterclockwise IOL rotation when the capsule contraction was dominant in the haptic part as well as clockwise rotation when dominant in the non-haptic part (p = 0.015). Conclusion The direction and degree of AcrySof toric IOL rotation differed throughout the follow-up period. Since most misalignments were found on the first post-operative day, physicians should try to minimize peri-operative risk factors that influence IOL rotation. There was also a correlation between the part of anterior capsule contraction and the direction of IOL rotation.