Studien- und Abschlussarbeiten

Postoperative refraction study for sutureless cataract surgery with standard 22 dioptre IOL

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Jahr:  2008
Studiengang:  Augenoptik / Augenoptik & Hörakustik
Kategorie:  Diplomarbeit
Erstbetreuer:  Prof. Dr. Annemarie Buser
Externer Betreuer: Dr. Nick Metcalfe
Ersteller: Markus Schwarzmann

AIMS: To evaluate the uncorrected and corrected visual outcomes of sutureless extracapsular cataract extraction (ECCE) and posterior chamber intraocular lens (PCIOL) implantation with standard power intraocular lenses (IOL) of 22 D in cases without immediately postoperative complications. Preoperative ultrasound biometry and keratometry was performed, in order to compare the refracted and predicted spherical equivalents in order to get an estimation of the quality of the biometry. It is important to know the quality of biometry for the prospective implement of biometry and individual power IOLs. LOCATION: Nkhoma Eye Hospital in rural Malawi, East Africa METHODS: Patients, operated with technique mentioned above, were examined for their visual acuity uncorrected and after objective and subjective refraction with the best correction. On a randomly chosen sample of these patients was ocular biometry done with a manual keratometer and an ultrasonography A-scan biometer (TOMEY AL 100). RESULTS: 298 eyes of 257 patients with cataract were examined. 8 patients were taken out from the evaluations because of lack of cooperation and one was a child. 95.2% of the patients came to the hospital with a preoperative VA ≤6/60, 4.1% had preoperative VA of 6/36 and 0.7% VA of 6/24. On 179 patients was biometry performed. The Examinations were carried out in average 1 to 6 days postoperative. Further follow-up controls were not possible in majority of the cases, as the patients live too far away from the hospital, but occurred accidentally. A best uncorrected vision postoperative of 6/9 - 6/18 was obtained in 56.3% of the cases, less than 6/18 - 6/60 in 43.7%. A best corrected vision postoperative was obtained in 96.2% with a VA of 6/5 - 6/18 and 3.8% with 6/24. The axial eye lengths ranged from 20.80 mm to 25.63 mm with a mean value of 22.89 mm (Standard Deviation SD: 0.87). Corneal power ranged from 37.41 D to 47.93 D with a mean value of 42.11 D (SD: 1.78). The astigmatic directions of the corneas were in 51.1% against-the-rule, in 22.3% with-the-rule and in 11.9% oblique. 14.7% of the corneas had no astigmatism. The predicted IOLS ranged from 16.5 D to 29.5 D. The mode was 22.5 D and the mean value 23 D (SD: 2.0). The spherical equivalents from refraction ranged from -6.50 D to 4.33 D with a mean value of -0.808 D (SD: 3.23). The predicted spherical equivalents ranged from -5.57 D to 5.86 D with a mean value of 0.49 D (SD: 1.64). CONCLUSION: The visual outcomes of sutureless ECCE with PCIOL are equal to other eye hospitals in developing countries, in some cases even better. The high range of spherical equivalents is an indication that the biometry implement was useful. On the other hand shows the discrepancy of the spherical equivalents that the biometry quality must still be improved by more practice in order to get experience. Keywords: Extracapsular cataract surgery, postoperative refraction, biometry implement, rural Africa