Early postoperative and long-term follow-ups showed effective and stable correction of astigmatism after implantation of a foldable toric posterior chamber silicone IOL.
Conclusions-Under high contrast conditions halos can be stimulated in all patients with multifocal intraocular lenses. The halo size using the distance or the near focus is identical. (Br J Ophthalmol 2001;85:816-821)
To compare the optical properties of bifocal diffractive and multifocal refractive intraocular lenses. Methods: A model eye with a pupil 4.5 mm in diameter was used to determine the point spread function (PSF) of the distance focus and near focus of a diffractive bifocal intraocular lens (IOL) (model 811E; Pharmacia Inc, Columbus, Ohio) and of a refractive multifocal IOL (model SA40N; Allergan Optical Inc, Irvine, Calif) to compare them with PSFs of foci of corresponding monofocal lenses. For interpreting the PSFs the through focus response, the modulation transfer function, and the Strehl ratio were evaluated. Results: The intensity of the distance focus of the bifocal diffractive lens reached 58.5% and the near focus attained 42.7% of the intensity of a corresponding monofocal lens. The maximal halo intensity surrounding both
Impairment of the lacrimal glands after external radiation has been well documented, but there are only a few reports on the effects of radioiodine therapy on the lacrimal glands. Long-term effects of high-dose radioiodine therapy on tear secretion have not previously been studied. We investigated 175 eyes of 88 patients with a history of radioiodine therapy for thyroid carcinoma (68 females, 20 males; mean age 55+/-16 years, range 17-81 years) and compared them with a sex- and age-matched control group ( n=39). All patients had been given at least 2.96 GBq iodine-131 (maximal administered activity 22.3 GBq (131)I). An ophthalmological investigation was performed 64+/-71 months (range 3-317 months) after initial radioiodine therapy by a single ophthalmologist. Lacrimal gland function was evaluated with three different function tests. External eye morphology was considered, and detailed ophthalmological history-taking was performed. Patients with factors known to affect lacrimal gland function (contact lenses, autoimmune disorders, history of additional radiation exposure) were excluded from the study. A total of 81 patients (92%) had at least one abnormal function test indicating impaired lacrimal gland function. Schirmer's tear test was decreased (<10 mm/5 min) in 47 of the 88 patients and definitely abnormal (<5 mm/5 min) in 35 patients. A tear film break-up time of <10 s was found in 78 patients, and 62 patients had a definitely abnormal break-up time of <5 s. The lacrimal lipid layer was impaired in 43 patients. The function tests were all significantly altered in the study group as compared with the controls ( P<0.005, P<0.001, P<0.001, respectively). Both subjective symptoms of dry eye ( P<0.01) and changes in the external eye morphology ( P<0.001) were significantly more prevalent in the study group. Our findings suggest that in the majority of patients, lacrimal gland function may be permanently impaired after high-dose radioiodine therapy. All three layers of the tear film are involved and there is a pronounced long-term effect on the tear film stability.
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