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Query: UMLS:C0086543 (cataract)
 29,165 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Excimer laser photorefractive keratectomy as a means to flatten the central cornea has generated considerable interest. With this technique radial symmetric ablations can be performed to correct myopic refractive errors and excise superficial corneal pathology. We developed a technique that uses toric ablation to correct astigmatism. A new mask was designed for the MEL 60 Aesculap-Meditec excimer laser. The mask can be rotated regularly over 360 degrees. By varying the angular distances, the surgeon can increase ablation depth in any desired meridian. As a result, both cylindrical and spherical errors can be corrected in one procedure. Seventy-three eyes with either simple, myopic, mixed, or irregular astigmatism were treated. In each category of astigmatism, the surgery reduced the spherical component as well as the overall mean preoperative cylindrical refraction. Our findings suggest that this technique is a safe and effective procedure for correcting different types of astigmatism.
J Cataract Refract Surg 1994 Mar
PMID:Photorefractive keratectomy to correct astigmatism with myopia or hyperopia. 800 96

A 38-year-old man with congenital nystagmus had laser in situ keratomileusis (LASIK) to correct a spherical equivalent of -11.0 diopters (D) in the right eye and -10.0 D in the left eye. Baseline uncorrected visual acuity (UCVA) was 20/400 in both eyes, and best spectacle-corrected visual acuity was 20/60 in the right eye and 8/20 in the left. The procedure was performed using the Aesculap Meditec MEL 60 excimer laser system and a semicircular suction ring device. Six months after LASIK, the patient had a UCVA of 20/60 in the right eye and 8/20 in the left eye, with no improvement with spectacle correction. Laser in situ keratomileusis can be performed with a semicircular suction ring device to correct refractive errors in patients with congenital nystagmus, but more cases have to be performed to confirm that the device is safe and suitable for these patients.
J Cataract Refract Surg 2001 Apr
PMID:Laser in situ keratomileusis in an eye with congenital nystagmus. 1131 36

A 29-year-old man with Schnyder's central crystalline dystrophy was treated with phototherapeutic keratectomy (PTK) in his right eye. Ocular examination revealed abnormal deposits of cholesterol and lipid within the corneal stroma (appearing as crystalline spindle-shaped deposits), high myopia, phakic anterior chamber intraocular lens implantation, and myopic macular degeneration in both eyes. Phototherapeutic keratectomy ablation to a central zone of 7.0 mm and a depth of 96 microm was performed with an Aesculap Meditec MEL-70 excimer laser. Confocal microscopy performed before PTK showed multiple deposits of large, brightly reflective crystalline material extending from the anterior to the mid stroma. The Z-scan curves revealed that the highest density of crystalline deposits was located within the first 140 microm of corneal depth. Six months after PTK, confocal microscopy showed a markedly decreased density of corneal crystalline deposits in the anterior stroma.
J Cataract Refract Surg 2001 Nov
PMID:Morphological evaluation of Schnyder's central crystalline dystrophy by confocal microscopy before and after phototherapeutic keratectomy. 1170 68

We report a topography-wavefront-guided repair procedure in a patient with a decentered optical zone and significant higher-order aberrations (HOAs) following radial keratotomy 14 years previously. The CRS-Master custom ablation software was used to generate a topography-wavefront-guided ablation profile based on Atlas front corneal surface topography data, and the MEL 80 excimer laser was used to treat the patient. Very high-frequency digital ultrasound scanning (Artemis) was performed before and after surgery to measure epithelial and stromal thickness changes to evaluate the anatomical congruity of the planned and achieved irregular ablation. Nine months postoperatively, the optical zone centration was topographically improved and HOAs were significantly lower, with a 90% reduction in spherical aberration. The stromal thickness change map demonstrated that the profile of stromal tissue removed matched the irregular ablation profile. However, the measured stromal thickness change at the maximum point was 33% higher than the predicted ablation depth. The epithelial thickness change measured in this case indicates that topography-guided treatments could be improved by taking epithelial thickness changes into account.
J Cataract Refract Surg 2011 Mar
PMID:Very high-frequency digital ultrasound evaluation of topography-wavefront-guided repair after radial keratotomy. 2133 82