Accuracy of Zernike Polynomials in Characterizing Optical Aberrations and the Corneal Surface of the Eye

2005 ◽  
Vol 46 (6) ◽  
pp. 1915 ◽  
Author(s):  
Luis Alberto Carvalho
Author(s):  
A. B. Bhatia ◽  
E. Wolf

ABSTRACTThe paper is concerned with the construction of polynomials in two variables, which form a complete orthogonal set for the interior of the unit circle and which are ‘invariant in form’ with respect to rotations of axes about the origin of coordinates. It is found that though there exist an infinity of such sets there is only one set which in addition has certain simple properties strictly analogous to that of Legendre polynomials. This set is found to be identical with the set of the circle polynomials of Zernike which play an important part in the theory of phase contrast and in the Nijboer-Zernike diffraction theory of optical aberrations.The results make it possible to derive explicit expressions for the Zernike polynomials in a simple, systematic manner. The method employed may also be used to derive other orthogonal sets. One new set is investigated, and the generating functions for this set and for the Zernike polynomials are also given.


2013 ◽  
Vol 3 (1) ◽  
pp. 1
Author(s):  
Cristina M. Oliveira ◽  
Sandra Franco

With the increasing importance of optical aberrations in both vision research and clinical practice, it becomes necessary for vision scientists to have a thorough understanding of the concepts behind wavefront optics. Therefore, in this review, we provide some basic wave optics concepts useful to understand wavefront analysis, and describe the application of Zernike polynomials in the decomposition of aberrations. A general description of the human eye optical structure is given, followed by a more detailed analysis of the optical components of the eye and optical aberrations, and their secondary effect on overall optical quality. We further provide an overview of the current corneal and ocular wavefront sensing methods.


1995 ◽  
Vol 34 (34) ◽  
pp. 8060 ◽  
Author(s):  
Virendra N. Mahajan

2020 ◽  
pp. 54-56
Author(s):  
B.I. Esergepova ◽  
◽  
G.K. Mukhataeva ◽  
M. Makenbaeva ◽  
◽  
...  

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Min-jie Ye ◽  
Cai-yuan Liu ◽  
Rong-feng Liao ◽  
Zheng-yu Gu ◽  
Bing-ying Zhao ◽  
...  

Purpose. To compare the change of anterior corneal higher-order aberrations (HOAs) after laser in situ keratomileusis (LASIK), wavefront-guided LASIK with iris registration (WF-LASIK), femtosecond laser-assisted laser in situ keratomileusis (FS-LASIK), and small incision lenticule extraction (SMILE).Methods. In a prospective study, 82 eyes underwent LASIK, 119 eyes underwent WF-LASIK, 88 eyes underwent FS-LASIK, and 170 eyes underwent SMILE surgery. HOAs were measured with Pentacam device preoperatively and 6 months after surgery. The aberrations were described as Zernike polynomials, and analysis focused on total HOAs, spherical aberration (SA), horizontal coma, and vertical coma over 6 mm diameter central corneal zone.Results. Six months postoperatively, all procedures result in increase of anterior corneal total HOAs and SA. There were no significant differences in the induced HOAs between LASIK and FS-LASIK, while SMILE induced fewer total HOAs and SA compared with LASIK and FS-LASIK. Similarly, WF-LASIK also induced less total HOAs than LASIK and FS-LASIK, but only fewer SA than FS-LASIK (P<0.05). No significant difference could be detected in the induced total HOAs and SA between SMILE and WF-LASIK, whereas SMILE induced more horizontal coma and vertical coma compared with WF-LASIK (P<0.05).Conclusion. FS-LASIK and LASIK induced comparable anterior corneal HOAs. Compared to LASIK and FS-LASIK, both SMILE and WF-LASIK showed advantages in inducing less total HOAs. In addition, SMILE also possesses better ability to reduce the induction of SA in comparison with LASIK and FS-LASIK. However, SMILE induced more horizontal coma and vertical coma compared with WF-LASIK, indicating that the centration of SMILE procedure is probably less precise than WF-LASIK.


2021 ◽  
Vol 22 (11) ◽  
pp. 5564
Author(s):  
Ronald M. Sánchez-Ávila ◽  
Natalia Vázquez ◽  
Manuel Chacón ◽  
Mairobi Persinal-Medina ◽  
Agustín Brea-Pastor ◽  
...  

The purpose of this work is to describe the use of Fibrin-Plasma Rich in Growth Factors (PRGF) membranes for the treatment of a rabbit alkali-burn lesion. For this purpose, an alkali-burn lesion was induced in 15 rabbits. A week later, clinical events were evaluated and rabbits were divided into five treatment groups: rabbits treated with medical treatment, with a fibrin-PRGF membrane cultured with autologous or heterologous rabbit Limbal Epithelial Progenitor Cells (LEPCs), with a fibrin-PRGF membrane in a Simple Limbal Epithelial Transplantation and with a fibrin-PRGF membrane without cultured LEPCs. After 40 days of follow-up, corneas were subjected to histochemical examination and immunostaining against corneal or conjunctival markers. Seven days after alkali-burn lesion, it was observed that rabbits showed opaque cornea, new blood vessels across the limbus penetrating the cornea and epithelial defects. At the end of the follow-up period, an improvement of the clinical parameters analyzed was observed in transplanted rabbits. However, only rabbits transplanted with cultured LEPCs were positive for corneal markers. Otherwise, rabbits in the other three groups showed positive staining against conjunctival markers. In conclusion, fibrin-PRGF membrane improved the chemically induced lesions. Nonetheless, only fibrin-PRGF membranes cultured with rabbit LEPCs were able to restore the corneal surface.


1993 ◽  
Vol 71 (11) ◽  
pp. 2282-2290 ◽  
Author(s):  
M. T. Pardue ◽  
J. G. Sivak ◽  
K. M. Kovacs

The corneal anatomy of fin whales (Balaenoptera physalus), minke whales (Balaenoptera acutorostrata), harp seals (Phoca groenlandica), ringed seals (Phoca hispida), and bearded seals (Eriganthus barbatus) was examined to determine if marine mammals have evolved specialized corneas for life in a marine habitat. One to seven eyes of each species were analyzed: paraffin sections stained with haematoxylin and eosin for light microscopy; and ultrathin sections for transmission electron microscopy. All corneas contain the five typical mammalian layers: epithelium, Bowman's layer, stroma, Descemet's membrane, and endothelium. The corneas of these marine mammals are thicker than human corneas because of a thicker stromal layer. The other layers are thinner than those found in humans, except for the epithelial layer in the bearded seal and the cetaceans where it may provide extra protection for the eye during feeding behaviour. The epithelial cells in all corneas studied have an abundance of tonofilaments, which may strengthen the cells and distribute force across the corneal surface. No special organization of collagen fibrils was found in the stroma that would offer protection from ultraviolet radiation or glare for pinnipeds when on ice. The thickness of the sclera in the cetaceans may serve to hold the inner globe of the eye in an elliptical shape, while the thinning of the sclera in the equatorial region in pinnipeds may flatten the eye in air to reduce aerial myopia.


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