Human corneal endothelium after excimer laser PRK.
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Biomedical subjects
Publications and source records attributed to M J Maldonado.
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AIMS: A prospective, randomised, double blind, placebo controlled study of intraoperative mitomycin C as adjunctive treatment of primary pterygium was conducted. METHODS: A total of 66 eyes of 54 patients with primary pterygium were treated with excision, with or without a single intraoperative application of mitomycin C (0.1 mg/ml for 5 minutes) to evaluate the efficacy and toxicity of this adjunctive treatment. The mean follow up was 14.1 months (range 12-23 months). RESULTS: Of the 36 eyes that underwent simple excision, 14 (38.8%) exhibited recurrences whereas only one of 30 eyes (3.33%) treated with excision and intraoperative application of mitomycin C had recurrence (p = 0.0006). Neither serious ocular complications nor systemic toxicity were noted in the mitomycin C treated group. CONCLUSION: Intraoperative mitomycin C appears to be an effective and safe adjunctive treatment of primary pterygium.
To ascertain the long-term effects of a triple procedure in the case of coexisting cataract and glaucoma, we did a retrospective study of 93 eyes that had cataract extraction, IOL implantation, and trabeculectomy within a ten-year period. Mean follow-up was 32.4 +/- 21.9 months. Mean postoperative intraocular pressure (IOP) was significantly lower than preoperatively, even though fewer medications were being used. One year after surgery, 60% of eyes had a best corrected visual acuity of 20/40 or better with an average improvement of 3.8 Snellen lines. Patients who had had surgery four or more years before the study had the highest percentage of eyes with an IOP exceeding 22 mm Hg. This group also had the poorest IOP control when no medications were used and when the patient took fewer medications than before surgery. The finding that IOP control decreases with postoperative time raises questions about the long-term success of the triple procedure in controlling IOP.
Eight cephalometric parameters were determined in individuals affected with cleft lip and cleft palate, their parents and siblings and a sample of normal individuals. No differences were found in males in any group. In contrast, affected females had lower measurements than their female relatives, and these lower latter in turn had measurements than control females. Although differences between groups were significant enough overlap existed and therefore genetic counseling based on these measurements would be uncertain.
The purpose of the present study was to determine if the administration of a biosynthetic human growth hormone (bGH) was able to enhance the efficacy of total parenteral nutrition (PN). Patients (n = 38) who had undergone major gastrointestinal surgery were randomly divided in two groups. Group I (n = 20) treated only with PN and Group II (n = 18) treated as in Group I plus bGH (4 UI/daily). Our study shows that the administration of bGH produces a significant increase in serum levels of growth hormone and Somatomedin-C. It also caused a positive nitrogen balance from the first 24 hours on (p less than 0.01). In Group II on day 12 after operation a statistically significant increase in transferrin (p less than 0.05), albumin (p less than 0.01) and total proteins (p less than 0.02) was observed. Our study suggest that the administration of bGH produces, perhaps through Somatomedin-C as mediator, an increase in protein synthesis.
BACKGROUND: Topography measures the centration in refractive and corneal refractive surgery, but until recently there was no effective method to measure decentration in intraocular lens (IOL) implantation. PATIENTS AND METHODS: We measured the decentration of 22 phakic eyes, in 14 high myopic patients, based upon photographs of the anterior segment using a digital analysis system (IMAGEnet Topcon Corporation 1988, Tokyo, Japan). These eyes had undergone IOL implantation for the correction of myopia with Worst-Fechner iris claw lenses. Decentration was measured with respect to the centers of both the cornea and pupil. RESULTS: Mean decentration of the IOL center from the cornea center was 0.51 +/- 0.25 mm (range, 0 to 0.8374 mm). When measured with respect to the center of the pupil, the average decentration was 0.47 +/- 0.29 mm (range, 0.182 to 0.9341 mm). A positive correlation between the decentration measurements of the two methods was found (p < .01 indicated statistical significance). CONCLUSIONS: This digital imaging system (IMAGEnet) accurately measured decentration of IOLs in myopic eyes.
BACKGROUND: High astigmatism can be corrected using trapezoidal or arcuate transverse keratotomies. Videokeratography enables qualitative evaluation of the corneal topography. METHODS: Fifty-five eyes of 41 patients presenting with high astigmatism after penetrating keratoplasty or naturally occurring astigmatism (mean, 6.29 diopters [D]; range, 3.00 to 16.00 D) underwent correction using either intersecting trapezoidal or arcuate transverse keratotomies. Corneal topographic maps were analyzed and classified into keratographic patterns. Mean follow up was 3 years (range, 1 to 6 years). RESULTS: The mean net decrease in refractive astigmatism was 3.60 D (52.7% reduction). The flattening/steepening ratio was on average higher for intersecting trapezoidal keratotomy (7.26 for astigmatism after penetrating keratoplasty and 8.31 for naturally occurring astigmatism) than for arcuate transverse keratotomy (.98 in astigmatism after penetrating keratoplasty and 1.76 in naturally occurring astigmatism). Accordingly, intersecting trapezoidal keratotomy tended to produce a hyperopic shift in the spherical equivalent refraction (mean hyperopic shift, 2.65 and .56 D, respectively). The mean vector-corrected change of refractive astigmatism after intersecting trapezoidal keratotomy was 88.8% in naturally occurring (n = 21 eyes) and 70.3% in penetrating keratoplasty astigmatism (n = 13). Arcuate transverse incisions corrected on average 79.9% of naturally occurring (n = 13) and 60.8% of penetrating keratoplasty astigmatism (n = 8). Videokeratography showed the asymmetric bowtie pattern as the most frequent pattern for both procedures. Intersecting trapezoidal keratotomy was characterized by relatively higher incidences of polygonal and irregular patterns. Arcuate transverse incisions caused less wound healing defects and glare than intersecting trapezoidal keratotomy. CONCLUSIONS: Both intersecting trapezoidal keratotomy and arcuate transverse incisions effectively reduced high naturally occurring astigmatism and astigmatism after penetrating keratoplasty. However, greater corneal surface irregularity and more complications were seen following intersecting trapezoidal keratotomy. Trapezoidal keratotomy should not be used unless a large decrease of myopia is needed, and then a nonintersecting technique is preferable.
PURPOSE/METHOD: To present a case of a 30 years old woman that suffered a car accident one year ago, diagnosed of cervical sprain. One month after the accident, the patient saw a black stein in the outer side of the visual field on the left eye. RESULTS/CONCLUSIONS: Brain CAT, evocate visual potentials, color test and MRI were within of the normality. According with the ophthalmic examination, visual field test and OCT (optical coherence tomography), the diagnosis was acute zonal occult outer retinopathy (AZOOR).
The photorefractive effect of excimer lasers is based on an interaction between the 193-nm ultraviolet-C laser beam and the stromal chromophore molecules. Recently, in some patients an increase of subepithelial haze and a regression of refractive effect has been observed following suntanning (UV-B exposure). The aim of the study was to find out the possible endothelial damage caused by photoablation with increasing depth and the effect of subsequent UV-B exposure on previously photokeratactomized eyes. Altogether 12 chinchilla rabbits were treated. Four animals received a -5.0 D PRK; four animals a -15.0 D PRK and four animals a -30.0 D PRK treatment. The endothelial average number, size and variation were determined two weeks post-PRK. Three weeks following PRK, a half of the animals received a 1 J/cm2 ultraviolet-B radiation in a constant dermatological UV-chamber. The endothelial morphology was measured the same way with automated specular microscopy two weeks after UV-B irradiation. After PRK treatment there was no statistically demonstrable change in endothelial morphology. On the other hand, after UV-B radiation all eyes showed a decrease in endothelial number and an increase in size and variation. The ratio of hexagonality decreased, and endothelial rosette formation appeared. The early morphological changes resembled the physiological aging changes. Conditions (deep stromal photoablation, cumulative effect of suntanning or solarium treatments) may exaggerate the physiological aging processes leading to subsequent pleomorphism, polymegatism and cell loss. This may accelerate corneal dysfunction.