Comparison of refractive outcome using intraoperative biometry and partial coherence interferometry in silicone oil-filled eyes.

INTRODUCTION: A-scan ultrasound is currently the most widely used technique for axial length measurement; however, this method is not optimal in silicone-oil filled eyes. Two techniques that may be more accurate for axial length measurements in these eyes are intraoperative measurement of axial length after silicone oil removal or measurement by Laser interferometry using the IOL Master. The purpose of this study is to evaluate and compare the accuracy of both intraoperative biometry and partial coherence interferometry in silicone oil-filled eyes. PATIENT AND METHODS: Axial length measurement of 22 cataractous silicone-filled eyes of 21 patients using both IOL Master Biometry and intraoperative A-scan biometry was performed. IOL power was then computed using the SRK-T formula. Accuracy of intraoperative biometry and partial coherence interferometry was evaluated by determining the mean actual postoperative refractive error. RESULTS: Comparing the predictability of intraoperative A-scan biometry and IOL Master Biometry, the two techniques showed small predictive postoperative refractive errors without a statistically significant difference in the predictive errors of the two techniques. CONCLUSION: Both intraoperative biometry by A-scan ultrasonography and partial coherence interferometer by IOL Master proved to have good equal predictability for absolute postoperative refractive error in cataract surgery for eyes filled with silicone oil.

Wandering nematode in the vitreous cavity.

BACKGROUND: Bancroftian filariasis is focally endemic in Egypt. There have been many reports of intraocular filariasis; the question of why one filarial nematode should cause ocular disease while another does not may be related to the behavior of the microfilaria and the location of the cross-reacting ocular antigen. METHODS: A 35-year-old woman with a white worm approximately 3 disk diameters in length penetrating the left macula, moving in the vitreous cavity, with a part of its length in the vitreous cavity while the rest was embedded subretinally, is described. Pars plana vitrectomy was performed and the worm was aspirated successfully. RESULTS: Parasitologic study of the aspirated worm identified juvenile Wuchereria bancrofti. Ivermectin 150 µg/kg was given orally to the patient after identification of the worm. Six weeks later, the patient's visual acuity had improved to 20/200. CONCLUSION: Intravitreal parasites should be surgically removed as soon as possible.