scholarly journals STUDY OF THE OPTICAL POWER OF NANOPHOTONIC SOFT CONTACT LENSES BASED ON POLY (2- HYDROXYETHYL METHACRYLATE) AND FULLERENE

2014 ◽  
Vol 5 (1) ◽  
Author(s):  
Aleksandra Debeljković Mitrović ◽  
Dragomir Stamenković ◽  
Manuel Conte ◽  
Božica Bojović ◽  
Spomenko Mihajlović

In this paper results of comparative study of the optical power of soft contact lenses (SCL) made of standard material for SCL and nanophotonic materials with different measurement techniques used for the final contact lens controllers are presented. Three types of nanophotonic soft contact lenses were made of standard polymacon material (Soleko SP38TM) incorporated with fullerene C60, fullerol C60(OH)24 and fullerene metformin hydroxylate C60(OH)12(OC4N5H10)12. For the purposes of material characterization for potential application as soft contact lenses, the optical properties of the soft contact lenses were measured by Rotlex and Nidek device. With Rotlex device the following optical results were obtained: optical power and map of defects, while with the Nidek device: optical power, cylinder power and cylinder axis. The obtained values of optical power and map of defects showed that the optical power of synthesized nanophotonic soft contact lens is same to the nominal value, while this was not the case for the standard soft contact lens. Also, the quality of the nanophotonic soft contact lens is better than the standard one. Hence, it is possible to synthesize new nanophotonic soft contact lenses of desired optical characteristics, implying possibilities for their application in this field.

2013 ◽  
Vol 67 (6) ◽  
pp. 861-870 ◽  
Author(s):  
Aleksandra Debeljkovic ◽  
Lidija Matija ◽  
Djuro Koruga

This work presents comparative research of characteristics of a basic and new nanophotonic material, the latter of which was obtained by incorporation fullerene, C60, in the base material for soft contact lenses. The basic (SL38) and nanophotonic materials (SL38-A) for soft contact lenses were obtained by radical polymerization of 2-hydroxyethyl methacrylate and 2-hydroxyethyl methacrylate and fullerene, which were derived by the technology in the production lab of the company Soleko (Milan, Italy). The materials were used for production of soft contact lenses in the company Optix (Belgrade, Serbia) for the purposes of this research. Fullerene was used due to its apsorption transmission characteristics in ultraviolet, visible and near infrared spectrum. For the purposes of material characterization for potential application as soft contact lenses, network parameters were calculated and SEM analysis of the materials was performed while the optical properties of the soft contact lenses were measured by a Rotlex device. The values of the diffusion exponent, n, close to 0.5 indicated Fick's kinetics corresponding to diffusion. The investigated hydrogels could be classified as nonporous hydrogels. With Rotlex device, values of optical power and map of defects were showed. The obtained values of optical power and map of defects showed that the optical power of synthesized nanophotonic soft contact lens is identical to the nominal value while this was not the case for the basic lens. Also, the quality of the nanophotonic soft contact lens is better than the basic soft contact lens. Hence, it is possible to synthesize new nanophotonic soft contact lenses of desired optical characteristics, implying possibilities for their application in this field.


2017 ◽  
Vol 2017 ◽  
pp. 1-17 ◽  
Author(s):  
L. Rico-Del-Viejo ◽  
M. Garcia-Montero ◽  
J. L. Hernández-Verdejo ◽  
S. García-Lázaro ◽  
F. J. Gómez-Sanz ◽  
...  

Objectives. To describe the past 20 years’ correction modalities for keratoconus and their visual outcomes and possible complications.Methods. A review of the published literature related to the visual outcomes and possible complications in the context of keratoconus management using nonsurgical procedures for the last 20 years (glasses and contact lenses) was performed. Original articles that reported the outcome of any correction modalities of keratoconus management were reviewed.Results. The most nonsurgical procedure used on keratoconus management is the contact lens fitting. Soft contact lenses and soft toric contact lenses, rigid gas-permeable contact lenses, piggyback contact lens system, hybrid contact lenses, and scleral and corneoscleral contact lenses form the contemporary range of available lens types for keratoconus management with contact lenses. All of them try to restore the vision, improve the quality of life, and delay surgical procedures in patients with this disease. Complications are derived from the intolerance of using contact lens, and the use of each depends on keratoconus severity.Conclusions. In the context of nonsurgical procedures, the use of contact lenses for the management of keratoconic patients represents a good alternative to restore vision and improve the quality of live in this population.


2021 ◽  
Vol 44 (1) ◽  
pp. 18
Author(s):  
Ruby Chiang ◽  
Rebecca Gao ◽  
Terry Chang ◽  
Jerry Chen ◽  
George Hsu

2021 ◽  
pp. 111-114
Author(s):  
Е.L. Usubov ◽  
◽  
I.A. Rusakova ◽  
E.M. Rakhimova ◽  
◽  
...  

A clinical case demonstrates that improper use of soft contact lenses can induce serious changes in the cornea, followed by long-term treatment, which in turn may be ineffective due to the developed antibiotic resistance. In similar cases, the use of UV crosslinking provides an additional antimicrobial effect, which ultimately allows the inflammatory process to be resolved. Key words: keratitis, soft contact lens, crosslinking.


1996 ◽  
Vol 118 (3) ◽  
pp. 341-348 ◽  
Author(s):  
GuoMing T. Funkenbusch ◽  
Richard C. Benson

An axisymmetric elastic shell deformation model has been created to predict the conformity of a soft contact lens when pressed against the eye. Regions of contact and gap may be predicted, and the nonuniform reaction pressure between the lens and eye may also be found. This is important for issues like abrasion and comfort. Bending, membrane and transverse shear loads within the lens are also computed. Commercial soft contact lenses and a representative eye shape are used for the examples. We find that the uniformity of loading against the eye is strongly affected by the degree to which the lens is shaped to fit the eye, and relatively unaffected by the thickness of the lens.


2017 ◽  
Vol 2017 ◽  
pp. 1-13 ◽  
Author(s):  
Lele Cui ◽  
Ming Li ◽  
Meixiao Shen ◽  
Fan Lu ◽  
Jianhua Wang

Objectives. To evaluate the centration and movement of soft contact lenses and to verify the repeatability of two repeated measurements of the lens centration and movement using ultra-long scan depth optical coherence tomography (UL-OCT). Methods. A 1-day Acuvue® Define™ lens was tested on both eyes of 10 subjects (5 males and 5 females; mean age, 31.6 years). The centration and blink-induced movement of the contact lens were measured using UL-OCT at 5 min and 30 min after insertion. The measurements were repeated once at each checkpoint. Results. Good repeatability was found in the lens centration and movement between the two repeated measurements at either checkpoint. The values of the lens movement were 0.457 ± 0.248 mm and 0.402 ± 0.229 mm at 5 min and decreased to 0.197 ± 0.065 mm and 0.211 ± 0.110 mm at 30 min after insertion for the right and left eyes, respectively (P<0.05). Conclusions. The custom-built UL-OCT presented good repeatability of centration and movement in Define lenses at 5 min and 30 min after insertion. Most of the lenses were centered temporal and inferior to the cornea during the first 30 min wearing period. Compared with 5 min after insertion, the lens was centered better and exhibited less movement at 30 min.


Author(s):  
Jose M González-Méijome ◽  
Sofia Claudia Peixoto-de-Matos ◽  
Antonio Queiros ◽  
Jorge M Jorge ◽  
Alberto Diaz-Rey

ABSTRACT Purpose To evaluate optical quality and visual function in keratoconus patients corrected with RGP contact lenses and a novel special design of silicone hydrogel contact lens. Materials and methods Twelve eyes of six patients with keratoconus were enrolled to experience a new soft contact lens (Soft-K) for keratoconus made of a silicone-hydrogel material and the outcomes were compared to the performance with gas permeable lenses and spectacles. The three situations were compared for monocular and binocular high (100%) and low contrast (10%) ETDRS LogMAR visual acuity and contrast sensitivity function (CSF). Results On average, there was an improvement of more than two lines in visual acuity over spectacle correction and this is statistically significant for both gas permeable (GP) and Soft-K lens (p < 0.001). Visual acuity was not significantly different between GP and Soft-K lens for high contrast acuity but was slightly higher with GP lens for low contrast under binocular conditions. Monocular CSF showed a marked improvement with the Soft-K lens and GP, compared to spectacles correction, particularly for medium and high frequencies; conversely. Conclusion Soft-K silicone hydrogel soft contact lens produces a clinical and statistically significant improvement in visual acuity and contrast sensitivity function over spectacle correction. How to cite this article González-Méijome JM, Peixoto-de- Matos SC, Queiros A, Jorge JM, Diaz-Rey A. Quality of Vision with Spectacles, Special Silicone Hydrogel and Gas Permeable Contact Lenses in Keratoconic Patients. Int J Kerat Ect Cor Dis 2013;2(2):56-59.


1999 ◽  
Vol 121 (2) ◽  
pp. 188-195 ◽  
Author(s):  
Guo Ming T. Funkenbusch ◽  
Richard C. Benson

A soft contact lens, because of its elasticity, can re-center itself over the cornea after it has been displaced by a blink. In this paper, a potential energy method is used to simulate the centering mechanism. Specifications for commercially available soft contact lenses and realistic eye shapes are used for the examples. With this technique we can compare the centering attributes of different lens and eye geometries.


2021 ◽  
Vol 18 (3) ◽  
pp. 518-526
Author(s):  
E. P. Tarutta ◽  
S. V. Milash ◽  
M. V. Epishina

Purpose: to study the effect of bifocal soft contact lens (BSCL) with an ADD of 4 diopters on peripheral refraction (PR), optical and ergonomic eye parameters in children with myopia.Patients and methods. 26 patients (52 eyes) with myopia –3.09 ± 1.13 diopters at the age of 10.04 ± 1.5 years without correction and with correction by BSCL Prima BIO Bi-focal ( Okay Vision Retail, Russia). All patients underwent a horizontal and vertical PR study on an open field autorefractometer Grand Seiko WAM-5500 (Japan), wavefront aberrations were studied on OPD-Scan III aberrometer (Nidek, Japan), contrast sensitivity under mesopic conditions were studied on a Mesotest 2 instrument (Oculus, Germany) and visual productivity was studied using test tables.Results. The visual acuity of the distance with a BSCL correction of 0.98 ± 0.04 did not differ (p = 0.26) from the maximum visual acuity corrected by spherocylindrical glasses of 0.99 ± 0.04. BSCL induces myopic defocus in all peripheral zones, with a maximum value of 15° and a sharp decrease of 30°. Peripheral myopic defocus induced by the lens at a horizontal and vertical angle of 15 degrees did not depend on the initial degree of myopia. BSCL increases the total RMS from 0.07 ± 0.02 μm to 0.19 ± 0.07 μm in the 3 mm zone (p < 0.01) and from 0.27 ± 0.09 μm to 1.18 ± 0, 23 μm in the 6 mm zone (p < 0.01), mainly due to an increase in spherical aberration from –0.0005 ± 0.006 μm to 0.06 ± 0.01 μm (p < 0.01) and from 0.01 ± 0.09 μm to 0.58 ± 0.14 μm (p < 0.01) in the 3 mm and 6 mm zones, respectively. An increase in the overall RMS in BSCL reduces the quality of eye optics and contrast sensitivity under mesopic conditions, but does not impair visual productivity.Conclusion. BSCLs with a high ADD of 4 diopters are capable of inducing significant myopic peripheral defocus due to the induction of spherical aberration, while maintaining high visual acuity and not changing ophthalmic ergonomics, which makes them a pathogenetically substantiated method for correcting myopia and preventing its progression in children and adolescents.


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