Undesired light images associated with ovoid intraocular lenses
| Autor: | Alan S. Crandall, Stephen H. Johnson, Douglas D. Koch, James A. Davison, Edward P. Geraghty, Stephen S. Lane, Samuel Masket |
|---|---|
| Rok vydání: | 1993 |
| Předmět: |
Optics and Photonics
medicine.medical_specialty Light genetic structures medicine.medical_treatment Vision Disorders Pilot Projects Intraocular lens Cataract Extraction Methylmethacrylate Prosthesis Design law.invention Clinical study Ovoid shape law Surveys and Questionnaires Ophthalmology Humans Methylmethacrylates Scattering Radiation Medicine Capsulorhexis Retrospective Studies Lenses Intraocular business.industry Incidence fungi eye diseases Sensory Systems Lens (optics) Optical phenomena Intraocular lenses Ovoid Surgery sense organs business |
| Zdroj: | Journal of Cataract and Refractive Surgery. 19:690-694 |
| ISSN: | 0886-3350 |
| DOI: | 10.1016/s0886-3350(13)80336-7 |
| Popis: | Ovoid intraocular lenses (IOLs) accounted for approximately 35% of the lenses implanted in 1991. Despite their popularity among surgeons, patient observations and complaints suggest that ovoid lenses are associated with undesired optical images postoperatively. A pilot clinical study was carried out to test that hypothesis. A multicentered investigation of 289 cases with well-centered IOLs determined that 45% of 168 patients with ovoid lenses observed unwanted optical phenomena at some time after surgery, whereas 17% of 121 patients with round IOLs had similar complaints. Based upon the preliminary clinical study a laboratory investigation was designed to assess optical performance differences between ovoid and round IOLs. One testing system used scatterometry and a second, ray tracing analysis. Both methods determined that the truncated, thickened edge of ovoid lenses was associated with significant light scattering, possibly accounting for the extraneous light images observed by some patients. The results of the clinical and laboratory investigations suggest that undesired optical images produced by ovoid IOLs are due to lens shape rather than to the reduced dimension of the optic. |
| Databáze: | OpenAIRE |
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