A theoretical model of the human eye based on ultrasound and corneal data

• Autorzy: Falhar M. , Rehak J.
• Języki publikacji: EN

Abstrakty

EN

The purpose of this study was to create a theoretical model of the eye based on a comparison of the real spherical equivalent of the eye and the calculated value of the axial refraction. The main contribution of this model is that it enables calculation of the equatorial plane of the lens for accurate assessment of the IOL position for a spherical eye model. The Gullstrand model of the eye was used as the source eye model and this was modified for the purposes of this study. The axial refraction of the final model of the eye was compared with the spherical equivalent. The accuracy of the developed model was statistically confirmed using statistic tests. Individual calculation of the axial refraction using it shows that IOL calculation is possible without any general statistical presumptions. It permits the calculation of variables with an accuracy accepted by inferential statistics. The accuracy of this theoretical eye model however, is limited by extreme values of variables - an extreme value provides a less accurate result.

Słowa kluczowe

EN

biometry; theoretical eye model; lens; nucleus; intraocular lens (IOL); intraocular lens; formula; axial refraction

• Wydawca: Oficyna Wydawnicza Politechniki Wrocławskiej
• Czasopismo: Optica Applicata
• Rocznik: 2009
• Tom: Vol. 39, nr 1
• Strony: 195--210
• Opis fizyczny: Bibliogr. 19 poz.

Twórcy

autor

Falhar M.

autor

Rehak J.

• Faculty of Science, Palacky University, Olomouc, Czech Republic

Bibliografia

• [1] HOLLADAY J.T., Standardizing constants for ultrasonic biometry, keratometry, and intraocular lens power calculations, Journal of Cataract and Refractive Surgery 23(9), 1997, pp. 1356–1370.
• [2] HOLLADAY J.T., Intraocular lens power calculations for the refractive surgeon, Operative Techniques in Cataract and Refractive Surgery 1(3), 1998, pp. 105–117.
• [3] HILL W.E., IOL power calculation accuracy: Advice on how to avoid common errors, Cataract and Refractive Surgery Today, October 2003.
• [4] MELOUN M., MILITKY J., Kompendium statistického zpracování dat, Academia, Praha 2002 (in Czech).
• [5] BARTSCH H.J., Matematické vzorce, Academia, Praha 2006 (in Czech).
• [6] HERMANS E., DUBBELMAN M., VAN DER HEIJDE R., HEETHAAR R., The shape of the human lens nucleus with accommodation, Journal of Vision 7(10), 2007, p. 16/1.
• [7] RUTRLE M., Brýlová optika, IDVPZ, Brno 1993 (in Czech).
• [8] POPIOLEK MASAJADA A., Numerical study of the influence of the shell structure of the crystalline lens on the refractive properties of the human eye, Ophthalmic and Physiological Optics 19(1), 1999, pp. 41–49.
• [9] SIEDLECKI D., KASPRZAK H., PIERSCIONEK B.K., Schematic eye with a gradient-index lens and aspheric surfaces, Optics Letters 29(11), 2004, pp. 1197–1199.
• [10] GARNER L.F., OOI C.S., SMITH G., Refractive index of the crystalline lens in young and aged eyes, Clinical and Experimental Optometry 81(4), 1998, pp. 145–150.
• [11] POPIOLEK MASAJADA A., KASPRZAK H.T., A new schematic eye model incorporating accommodation, Optometry and Vision Science 76(10), 1999, pp. 720–727.
• [12] ELEFTHERIADIS H., IOLMaster biometry: refractive results of 100 consecutive cases, British Journal of Ophthalmology 87(8), 2003, pp. 960–963.
• [13] VERHULST E., VRIJGHEM J.C., Accuracy of intraocular lens power calculations using the Zeiss IOL Master. A prospective study, Bulletin de la Societe Belge d Ophtalmologie, No. 281, 2001, pp. 61–65.
• [14] RAJAN M.S., KEILHORN I., BELL J.A., Partial coherence laser interferometry vs conventional ultrasound biometry in intraocular lens power calculation, Eye 16(5), 2002, pp. 552–556.
• [15] VETRUGNO M., CARDASCIA N., CARDIA L., Anterior chamber depth measured by two methods in myopic and hyperopic phakic IOL implant, British Journal of Ophthalmology 84(10), 2000, pp. 1113–1116.
• [16] KORANYI G., LYDAHL E., NORRBY S., TAUBE M., Anterior chamber depth measurement: A-scan versus optical method, Journal of Cataract and Refractive Surgery 28(2), 2002, pp. 243–247.
• [17] ELDER M.J., Predicting the refractive outcome after cataract surgery: the comparison of different IOLs and SRK-II v SRK-T, British Journal of Ophthalmology 86(6), 2002, pp. 620–622.
• [18] NAESER K., Intraocular lens power formula based on vergence calculation and lens design, Journal of Cataract and Refractive Surgery 23(8), 1997, pp. 1200–1207.
• [19] SIEDLECKI D., NOWAK J., ZAJAC M., Placement of a crystalline lens and intraocular lens: retinal image quality, Journal of Biomedical Optics 11(5), 2006, p. 054012.