• Title/Summary/Keyword: Intraocular lenses

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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.

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.

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.

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.

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.

Comparison of Intraocular Lens Power Calculation Methods Following Myopic Laser Refractive Surgery: New Options Using a Rotating Scheimpflug Camera

  • Cho, Kyuyeon;Lim, Dong Hui;Yang, Chan-min;Chung, Eui-Sang;Chung, Tae-Young
    • Korean Journal of Ophthalmology
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    • v.32 no.6
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    • pp.497-505
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    • 2018
  • Purpose: To evaluate and compare published methods of calculating intraocular lens (IOL) power following myopic laser refractive surgery. Methods: We performed a retrospective review of the medical records of 69 patients (69 eyes) who had undergone myopic laser refractive surgery previously and subsequently underwent cataract surgery at Samsung Medical Center in Seoul, South Korea from January 2010 to June 2016. None of the patients had pre-refractive surgery biometric data available. The Haigis-L, Shammas, Barrett True-K (no history), Wang-Koch-Maloney, Scheimpflug total corneal refractive power (TCRP) 3 and 4 mm (SRK-T and Haigis), Scheimpflug true net power, and Scheimpflug true refractive power (TRP) 3 mm, 4 mm, and 5 mm (SRK-T and Haigis) methods were employed. IOL power required for target refraction was back-calculated using stable post-cataract surgery manifest refraction, and implanted IOL power and formula accuracy were subsequently compared among calculation methods. Results: Haigis-L, Shammas, Barrett True-K (no history), Wang-Koch-Maloney, Scheimpflug TCRP 4 mm (Haigis), Scheimpflug true net power 4 mm (Haigis), and Scheimpflug TRP 4 mm (Haigis) formulae showed high predictability, with mean arithmetic prediction errors and standard deviations of $-0.25{\pm}0.59$, $-0.05{\pm}1.19$, $0.00{\pm}0.88$, $-0.26{\pm}1.17$, $0.00{\pm}1.09$, $-0.71{\pm}1.20$, and $0.03{\pm}1.25$ diopters, respectively. Conclusions: Visual outcomes within 1.0 diopter of target refraction were achieved in 85% of eyes using the calculation methods listed above. Haigis-L, Barrett True-K (no history), and Scheimpflug TCRP 4 mm (Haigis) and TRP 4 mm (Haigis) methods showed comparably low prediction errors, despite the absence of historical patient information.

Clinical Study of Cataract Surgery in Diabetic Retinopathy (당뇨망막증 환자의 백내장 수술에 대한 임상적 고찰)

  • Park, Young-Hoon
    • Journal of Yeungnam Medical Science
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    • v.11 no.1
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    • pp.153-159
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    • 1994
  • Extracapsular cataract extraction with posterior chamber intraocular lens in 24 eyes of 24 diabetics, with and without diabetic retinopathy, were followed up postoperatively for an average of 14 months to determine the incidence of progression of diabetic retinopathy, the final visual acuity and factors predictive of progression of retinopathy and final visual acuity. Overall, retinopathy progressed in 52% of operated-on eyes. Cataract extraction was highly associated with progression of diabetic retinopathy. Women had a significantly increased risk of progression of retinopathy in the operated-on eye compared to men. Visual acuity improved in 22 of 24 orerated-on eyes : however, only 11 eyes achieved a visual acuity of 0.5 or better and only 7 eyes achieved a visual acuity of 0.7 or better. Patients treated with oral hypoglycemic agents had a worse visual prognosis than those treated with insulin. The prognosis of patients with diabetic retinopathy about to undergo cataract surgery, even extracapsular cataract extraction with placement of a posterior chamber lens, is guarded.

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