Predicting initial base curve of the rigid contact lenses according to Javal keratometry findings in patients with keratoconus

2020 ◽  
Author(s):  
Fereshte Berjandy ◽  
Payam Nabovati ◽  
Hassan Hashemi ◽  
Abbasali Yekta ◽  
Hadi Ostadimoghaddam ◽  
...  
Keyword(s):  
Contact Lenses ◽  
Base Curve ◽  
Rigid Contact ◽  
Initial Base

scholarly journals Preliminary Clinical Exploration of Scleral Lens Performance on Normal Eyes

2018 ◽  
Vol 2 (2) ◽  
pp. e14-e21
Author(s):  
Melissa Barnett ◽  
Jonathon Ross ◽  
Blythe Durbin-Johnson
Keyword(s):  
Visual Acuity ◽  
Contact Lens ◽  
Healthy Subjects ◽  
Contact Lenses ◽  
Front Surface ◽  
Contact Lens Wear ◽  
Factors Associated ◽  
Rigid Contact ◽  
Lens Wear ◽  
Spectacle Correction

Abstract Objectives: The purpose of this study was to evaluate the performance (i.e. vision, comfort and fit) of spherical and front-surface toric scleral lenses in subjects with regular, healthy corneas. Methods: Scleral lenses were fitin the eyes (n = 16) of healthy subjects (n = 9) with regular corneas, absent of pathology, and studied using an observational, multi-visit design. Lens fit was objectively evaluatedby an experienced practitioner.Following 1 month of successful lens wear, participants completedsubjective satisfaction surveys regarding the scleral lens wearing experience. Results:  According to participant surveys, scleral lenses were subjectively preferred over soft toric or gas permeable contact lenses in 88% of eyes, including in all eyes fit with a front-surface toric scleral lens (n = 3). Seventy-five percent (75%) of eyes achieved visual acuity of 0.1 logMAR or better, while all eyes with prior spectacle wear achieved visual acuity with a scleral lens within 1 Snellen line of spectacle correction. Seventy-five percent (75%) of eyes achieved good subjective comfort with a scleral lens. No participants reported poor subjective vision and/or comfort. Conclusions:  Our findings suggest that subjects preferred the performance of a scleral lens (spherical or front-surface toric) compared to a soft toric or gas permeable contact lens. Moreover, scleral lenses may provide a viable, alternative contact lens modality option for patients considering discontinuation of traditional soft toric and/or rigid contact lens wear; so long as the factors associated with hypoxia remain minimized. Key Words:  scleral lens; scleral contact lens; front-surface toric scleral lens; lens performance; normal eyes; healthy eyes

Tolerance to spherical aberration induced by rigid contact lenses

1992 ◽  
Vol 12 (1) ◽  
pp. 24-28 ◽  
Author(s):  
M. J. Collins ◽  
B. Brown ◽  
D. A. Atchison ◽  
S. D. Newman
Keyword(s):  
Contact Lenses ◽  
Spherical Aberration ◽  
Rigid Contact

Contact Lenses in the Management of Corneal Dystrophies

2019 ◽  
Vol 237 (02) ◽  
pp. 175-179
Author(s):  
Asim Visal Farooq ◽  
Kathryn Colby
Keyword(s):  
Contact Lenses ◽  
Patient Comfort ◽  
Bullous Keratopathy ◽  
Review Of The Literature ◽  
Soft Contact ◽  
Soft Contact Lenses ◽  
Corneal Dystrophies ◽  
Tissue Healing ◽  
Rigid Contact ◽  
Irregular Astigmatism

AbstractAmong the group of diseases comprising corneal dystrophies, there are a number for which contact lenses may be considered. For example, soft contact lenses may be beneficial in the management of recurrent corneal erosions and advanced bullous keratopathy and may lead to disease attenuation in some conditions. They also may be used in conjunction with surgical procedures to promote tissue healing and patient comfort in the postoperative period. Rigid contact lenses may be beneficial in the setting of irregular astigmatism. The present review of the literature will discuss the use of contact lenses in the management of corneal dystrophies.

Topographical Thickness of the Epithelium and Total Cornea after Overnight Wear of Reverse-Geometry Rigid Contact Lenses for Myopia Reduction

2003 ◽  
Vol 44 (11) ◽  
pp. 4742 ◽  
Author(s):  
Jianhua Wang ◽  
Desmond Fonn ◽  
Trefford L. Simpson ◽  
Luigina Sorbara ◽  
Richard Kort ◽  
...  
Keyword(s):  
Contact Lenses ◽  
Rigid Contact

Nanophotonic Rigid Contact Lenses: Engineering and Characterization

2013 ◽  
Vol 633 ◽  
pp. 239-252
Author(s):  
Đuro Koruga ◽  
Dragomir Stamenković ◽  
Ivan Djuricic ◽  
Ivana Mileusnic ◽  
Jovana Šakota ◽  
...  
Keyword(s):  
Contact Lens ◽  
Materials Science ◽  
Contact Lenses ◽  
Base Material ◽  
Material Structure ◽  
Exclusion Zone ◽  
Characterization Methods ◽  
Rigid Contact ◽  
Complex Engineering

Contact lenses are a common optical aid to provide help with refractive anomalies of the human eye. Construction of contact lenses is a complex engineering task as it requires knowledge of optics, materials science, production and characterization methods for product quality. Besides correcting refractive anomalies, by using contact lenses it is possible to change the characteristics of light through the manipulation of material structure properties. Nanomaterials, such as fullerene C60, are candidates for the medium that interacts with light, thus changing its properties. During material syntheses for contact lenses, fullerenes are added to the base material and optical characteristics of the new nanophotonic material are compared with the base material. The engineering, manufacture and characterization of both a commercial and a new nanophotonic contact lens is presented in this paper. The interaction of water with both base and nanophotonic contact lens materials is described. Using experimental techniques, the phenomena of an exclusion zone (EZ) is also identified.

Keratoconic Bi-aspheric Contact Lenses

2016 ◽  
Vol 5 (3) ◽  
pp. 132-138
Author(s):  
Ariela Gordon-Shaag ◽  
Philip Fine ◽  
Liat Gantz ◽  
Arige Gideon-Abousaid ◽  
Gad Serero
Keyword(s):  
Visual Acuity ◽  
Contact Lenses ◽  
Case Series ◽  
Visual Stability ◽  
Wavefront Aberrations ◽  
Body Sensation ◽  
Quality Of Vision ◽  
Base Curve ◽  
Aspheric Lenses

ABSTRACT Aim This observational clinical case series examined patients with keratoconus (KC) fit with keratoconic bi-aspheric (KBA) lenses to assess visual acuity (VA), wavefront aberrations, physiological fitting, subjective comfort, and manufacturer's fitting guidelines. Materials and methods Seven adult patients (11 eyes, four females, mean age: 34.15 ± 14.12) with nipple cones from the Hadassah Academic College contact lens clinic (Jerusalem, Israel) were fit with KBA lenses by modifying the initial base curve (BC) to obtain an acceptable physiological fit. The uncorrected and corrected distance (D) and near (N) Snellen VA and the ocular wavefront measurements, and responses to a self-administered five-point scale questionnaire were compared after 2 weeks of wear using paired two-tailed t-test or Mann-Whitney U test, as appropriate. Results Visual acuity and total root mean square (RMS) improved significantly with the lenses (DVAuncorrected = 0.04 ± 0.02, DVAcorrected = 0.66 ± 0. 22, NVAuncorrected = 0.34 ± 0.30, NVAcorrected = 0.95 ± 0.12). Subjects reported an average of 7.0 ± 2.7 hours of wear daily, with good scores in visual stability, satisfaction with VA and quality of vision, improvement of mood and quality of life, and low scores in foreign body sensation, pain, red eye, and itching during wear, and difficulty with lens removal. An average of two BC modifications from the diagnostic lens were necessary (0.16 mm steeper in nine eyes, 0.27 mm flatter in two eyes). Conclusion Keratoconic bi-aspheric lenses can provide 7 hours of comfortable wear, significantly improved VA and total RMS aberrations, alongside subjective satisfaction. Base curve modifications can be reduced by fitting a diagnostic lens 0.75 mm steeper than the flattest keratometry reading. How to cite this article Gantz L, Gordon-Shaag A, Gideon-Abousaid A, Serero G, Fine P. Keratoconic Bi-aspheric Contact Lenses. Int J Kerat Ect Cor Dis 2016;5(3):132-138.

Sign in / Sign up

Export Citation Format

Share Document