Endophthalmitis involving an Arthrobacter-like organism following intraocular lens implantation.
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Aged↗
Biomedical subjects
J J Perez-Santonja
Publications and source records attributed to J J Perez-Santonja.
Photorefractive keratectomy after radial keratotomy.
We report the results of a prospective study that evaluated the efficacy, predictability, and safety of excimer laser photorefractive keratectomy (PRK) to correct residual myopia after radial keratotomy (RK). Using a 193 nm excimer laser, we performed PRK on ten undercorrected myopic eyes that had previous RK surgery. The mean interval between the RK and PRK was 1.5 years. Mean follow-up was seven months. Mean preoperative refraction was -4.08 +/- 1.35 diopters (D) and after PRK was +1.61 +/- 1.18 D at three months, +1.05 +/- 0.75 D at six months, and +0.79 +/- 0.83 D at 12 months. An uncorrected visual acuity of 20/40 or better was achieved in eight eyes at three months, seven eyes at six months, and three eyes at 12 months. One eye had a transient loss of two Snellen lines of best spectacle corrected visual acuity because of increased haze. No other significant complication was noted. Our study shows that PRK is a predictable, effective, stable, and safe technique to correct residual myopia after RK. The results were similar to those of PRK without prior surgery, although we noted a slightly greater hyperopic deviation. We believe that eyes undercorrected by RK may benefit from subsequent PRK.
Adult↗
Corneal endothelial permeability after implantation of angle-fitted anterior chamber lenses in myopic phakic eyes. Preliminary results.
This present study aimed to evaluate the corneal endothelium after implantation of angle-fixed anterior chamber lenses in myopic phakic eyes. Twelve eyes (9 patients) with high myopia (more than-14 diopters) were implanted with ZB5M lenses (Domilens, France). The corneal endothelium was studied by fluorophotometry (endothelial transfer coefficient: kc.ca), specular microscopy and ultrasonic pachimetry. Tests were performed prior to and 3 and 6 months after the surgery. The Wilcoxon rank test was used for the statistical analysis of the data. There was a significant difference (p < 0.05) between the preoperative kc.ca (4.15 +/- 0.72 x 10(-3) min-1) and the kc.ca three months after the implantation (4.43 +/- 0.87 x 10(-3) min-1). A statistically significant difference (p < 0.01) was also found between the three and six months postoperative kc.ca (5.31 +/- 0.81 x 10(-3) min-1). There was a significant difference (p < 0.05) between the preoperative central endothelial cell density (2533 +/- 219 cells/mm2). No significant differences were found in relation to the central corneal thickness. In conclusion, three months after the implantation of ZB5M lenses to correct high myopia in phakic eyes, the corneal endothelial function was altered and continued to be so six months after the operation.
Adult↗
A model to explain the difference between changes in refraction and central ocular surface power after laser in situ keratomileusis.
PURPOSE: After refractive surgery, changes in central ocular surface power are usually less than actual changes in refraction. The aim of this paper was to examine the theoretical changes in the radius of the epithelial-stromal interface and corneal stromal refractive index which could take place to account for some of the empirical findings. METHODS: The parameters of an aspheric human eye model featuring gradient index optics was modified using data from a clinical study evaluating effects of laser in situ keratomileusis (LASIK) for correction of moderate to high myopia. Computations were performed to determine: 1) theoretical postoperative radius of the epithelial-stromal interface and hence distribution of epithelial thickness, and 2) refractive index of the stroma when the epithelium was of fixed uniform thickness. RESULTS: Within the central 2-mm diameter refractive zone of the cornea after LASIK for myopia, either of two factors could account for the difference between changes in central ocular surface power and the actual change in ocular refraction: 1) a steepening of the epithelial-stromal interface resulting from a 400% centrifugal increase in epithelial thickness, or 2) a reduction in stromal refractive index from an average of 1.376 to 1.364. CONCLUSION: The difference between the observed changes in refraction and central ocular surface power could be explained by reduction in stromal refractive index and this could be secondary to a 6.5% increase in water content of the stroma during the postoperative period. The epithelial-stromal interface after LASIK is unlikely to steepen by the extent predicted by our model. This surface is not the source of the difference between the change in refraction and change in central ocular surface power.
Corneal Stroma↗
Relationship between anterior chamber depth, refractive state, corneal diameter, and axial length.
PURPOSE: Phakic intraocular lenses are being used increasingly to correct refractive errors. We studied the relationship between anterior chamber depth, refractive state of the eye, spherical equivalent refraction, axial length of the globe, corneal diameter, and keratometry. METHODS: Two hundred eleven eyes of 211 patients were enrolled. All eyes underwent the same protocol with a complete ocular examination that included slit-lamp microscopy, intraocular pressure, objective and subjective refraction, calculation of the spherical equivalent refraction, corneal pachymetry, anterior chamber depth, axial length of the globe, and keratometry. All results were analyzed statistically using SPSS statistics software. Correlations between different parameters were studied using the Pearson correlation test. RESULTS: The anterior chamber depth was found to correlate significantly with both the average corneal diameter and the axial length of the globe (0.744, 0.531, P < .01) and was also found to correlate through an inverse relation with both age and spherical equivalent refraction (-0.391, -0.623, P < .01). Corneal thickness and keratometric power did not correlate with the anterior chamber depth. CONCLUSION: Most parameters (axial length, corneal diameter, spherical equivalent refraction, patient age) affected anterior chamber depth and should be considered carefully when planning refractive procedures that employ phakic intraocular lenses.
Adolescent↗
Short-term corneal endothelial changes after photorefractive keratectomy.
Clinical results show that photorefractive keratectomy (PRK) offers good predictability, efficacy, and safety. However, its potential risks on the human corneal endothelium are poorly known. We report the results of a prospective study conducted to evaluate the corneal endothelium changes after photorefractive keratectomy. Preoperative and serial postoperative specular microscopy was performed in 14 eyes undergoing excimer laser photorefractive keratectomy. The endothelium was analyzed for a variety of parameters, including cell density, coefficient of variation in cell size, and hexagonality. The follow-up was 6 months. The mean cell density was unchanged from 2463 cells/mm2 to 2498 cells/mm2 at 6 months after photorefractive keratectomy. The coefficient of variation of cell size (polymegathism) changed from 0.303 to 0.280 at 1 month, to 0.293 at 3 months, and to 0.290 at 6 months after surgery. The changes in this parameter were statistically significant when comparing pre- versus 1 month postoperative values. The hexagonality was unchanged from 72.08% at baseline to 73.35% at 6 months. No endothelial abnormalities were found after photorefractive keratectomy. Our results suggest a cell migration from the peripheral to central cornea after photorefractive keratectomy in contact lens wearing patients prior to photorefractive keratectomy.
Adult↗