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| Identifier |
000352356 |
| Title |
Αξιολόγηση της απορρόφησης μπλε φωτός από τον κρυσταλλοειδή φακό και από ενδοφακούς με και χωρίς χρωμοφόρο |
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Author
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Κονταδάκης, Γεώργιος
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Thesis advisor
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Τσιλιμπάρης, Μιλτιάδης
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Reviewer
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Πλαϊνης, Σωτήρης
Μοσχανδρέα, Ιωάννα
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| Abstract |
Introduction:
It is known that the normal crystalline lens accumulates chromophores that absorb UV and the shorter wavelengths of the visible spectrum that are considered to be primarily responsible for light damage to the retina. The lens extraction and implantation of a clear IOL presumably eliminates blue light filtering and increases the danger of light induced retinal damage. Due to this speculation, currently there are several tinted IOLs manufactured12-16 and the AcrySof® Natural IOL by Alcon© Laboratories is one of the most utilized. The light transmission spectrum of the AcrySof® Natural and other not tinted IOLs have been measured and compared only in laboratory settings. It has been estimated that the yellow tinted IOLs have absorption characteristics similar to those of the crystalline lens of a fifty year old man and the clear IOLs have very different characteristics.
The purpose of our study is to compare lens absorption in vivo, as estimated by blue light luminance perception, of patients that carry the AcrySof® Natural with patients that carry clear IOLs and with their preoperative status.
Method
Subjects: We enrolled 43 patients (mean age 65.3, range 36-82 years) that underwent lens extraction and acrylic IOL implantation due to cataract or refractive reasons. Only one eye of each patient was included and if both eyes were operated the choice was random. Subjects were measured the day before surgery and the 15th postoperative day. 21 patients received the AcrySof Natural® IOL (Alcon© Laboratories) and 23 a non-tinted acrylic IOL.
Technique: Lens absorption was assessed by means of Heterochromatic Flicker Photometry (HFP) using the QuantifEYETM Macular Pigment Screener. In HFP the measurement is based on the comparison of the perceived intensity of light between two sources of different wavelengthThe results were analyzed statistically with the SPSS programme.
Results
In the preoperative results using multiple regression analysis we found that lens absorption depends on age. In the postoperative results such a correlation with age did not exist, indicating that it is the lens that absorbs more with age. Tinted IOLs absorbed significantly more compared to clear IOLs. In the tinted IOL group no significant difference was found between the preoperative and postoperative results, while in the non-tinted group there was a statistically significant reduction of blue light attenuation postoperatively. The postoperative result of the tinted IOL group had a significant positive correlation with the IOL dioptric power which can be attributed to the IOL’s thickness.
Conclusions:
The preoperative results indicate that the blue light attenuation is increasing with age, and since this does not exist postoperatively it can be attributed to the crystalline lens. The tinted IOLs absorb at the blue spectrum and their absorption seems to vary proportionately to lens’ thickness. In general, they appear to mimic the light-attenuating characteristics of the ageing lens. This may offer protection to the retina from the photochemical damage that is believed to be related to high energy short wavelength radiation.
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| Physical description |
78 σ. : πιν. ; 30 εκ. |
| Language |
Greek |
| Subject |
Lens, Crystalline |
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Ophthalmology |
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Φακός, Κρυσταλλοειδής |
| Issue date |
2008-07-30 |
| Collection
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School/Department--School of Medicine--Department of Medicine--Post-graduate theses
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Type of Work--Post-graduate theses
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| Notes |
Διατμηματικό μεταπτυχιακό πρόγραμμα σπουδών: "Οπτική και Όραση" |
| Views |
231 |
Αξιολόγηση της απορρόφησης μπλε φωτός από τον κρυσταλλοειδή φακό και από ενδοφακούς με και χωρίς χρωμοφόρο
