PubMed · 1025174
The source did not provide an abstract. Follow the original record for more information.
Explore connections, maps & timelines
H D Kahn. 1976. Complete optometric care.. https://pubmed.ncbi.nlm.nih.gov/1025174/
Cite the original work for its findings. Save a collection to share your selection of sources.
KEEP EXPLORING
Spectacles have become a problem of life-style in some societies. In the USA, in 1999 approximately 1 million LASIK operations have been performed to correct myopia and astigmatism and in Europe the frequency of refractive surgery stead by increases. However, only 3 to 5% of these operations are medically indicated. Refractive surgery is evaluated regarding safety and efficacy. Modern laser techniques demonstrate excellent refractive results: photorefractive keratectomy (PRK) achieved refractive success rates of 90% and more with complication rates of 0.5% and less. PRK is, therefore, a valuable technique for corrections of myopia up to -6.0 D. Similar efficacy is obtained with LASIK (laser in situ keratomileusis) in corrections up to -10 D, however, the complication rate is somewhat higher. Laser correction of hyperopia is equally successful regarding the refractive success but shows an even higher complication rate and the patient satisfaction is lower. Modern refractive laser surgery may replace spectacles in the majority of the cases, however, none of the techniques is free of complications. Therefore, we understand refractive surgery still to be inferior to the correction of ametropia by means of spectacles and any such operation should be attempted only after thorough discussion.
Explore the source record for details and available documents.
BACKGROUND: Correction of an astigmatism at the time of cataract surgery can be achieved in two different ways, by alteration of the corneal curvature or by implantation of a toric intraocular lens (toric IOL). In the latter, in addition to the wound architecture and IOL calculation, the influence of rotational stability in the capsular bag is most important for the refractive result. PATIENTS AND METHODS: This retrospective study included 26 eyes from 24 patients with a corneal astigmatism of 2.5-11 D before cataract surgery of which 24 eyes showed a congenital astigmatism and 2 eyes an astigmatism after keratoplasty. After phakoemulsification a three-piece toric PMMA customised IOL (6.5/13.75 mm) was implanted into the capsular bag. Subjective and objective refraction as well as keratometry and corneal topography were performed pre- and postoperatively. The axis of the toric IOL cylinder was marked and could be measured precisely in the postoperative period. The surgically induced astigmatism (SIA) was calculated. RESULTS: At a mean follow-up time of 12 months after the implantation of a toric IOL, all eyes showed a reduction of total astigmatism. The mean total refractive astigmatism could be reduced from 4.16 D +/- 1.58 D preoperatively to 1.64 D +/- 1.21 D postoperatively. In 6 out of the 26 eyes (23%) the toric IOL rotated more than 10 degrees in the capsular bag and in all 6 cases the IOL rotation happened in the first 3 weeks postoperation. The IOL position was surgically corrected within 3-6 weeks after initial surgery and remained stable during the follow-up period. CONCLUSIONS: The implantation of a PMMA toric IOL is a promising procedure to correct higher levels of corneal astigmatism in cataract surgery. The initial rotational stability of the haptics in the capsular bag still has to be improved and the corneal SIA has to be reduced by smaller incisions. Therefore, three-piece foldable IOLs with a new haptic design are under development.