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Biomedical subjects

J Colin

Publications and source records attributed to J Colin.

At least 307 records · Page 17Linked to original sources
PubMedDate not supplied

Inferior steepening is associated with thinning of the inferotemporal cornea.

PURPOSE: Videokeratography has enabled detection of inferior steepening patterns in patients thereby designated as keratoconus suspects. Since no information about the corneal thickness of these eyes is available, we studied several patients with such patterns, and compared the corneal thickness of their eyes with that of normals. METHODS: Three groups of patients who had undergone videokeratography were studied with ultrasonic pachymetry centrally and in four quadrants at the 3-mm clear zone: 44 eyes with true keratoconus, 23 eyes of individuals with inferior steepening of the cornea who were family members of patients with keratoconus; and 44 normal eyes never fitted with contact lenses. The corneal thickness of the eyes in the first two groups was then compared with that in the third using ANOVA and Student's t test. RESULTS: Corneal thickness in the normal eyes and in those with inferior steepening was similar in all except the inferotemporal quadrant. In this quadrant, the corneas of the eyes with inferior steepening were thinner than those of the normal eyes: 544 +/- 32 microns vs 581 +/- 30 microns (p < .05) CONCLUSION: Eyes with inferior steepening on videokeratography have thinner inferotemporal corneas than normal eyes.

Adult↗
PubMedDate not supplied

Hot needle thermal keratoplasty to correct naturally occurring hyperopic astigmatism.

OBJECTIVE: To study the safety, effectiveness, predictability and stability of sectoral thermal keratoplasty in the treatment of naturally occurring hyperopic astigmatism. METHODS: Using Fyodorov's technique, sectoral controlled coagulations were applied on both sides of the flattest meridian in 12 eyes from eight patients with naturally occurring hyperopic astigmatism. Preoperative average refractive cylinder was +3.19 +/- 1.13 diopters (D), and the mean spherical component was +0.71 +/- 1.03 D. Mean follow-up time was 13.2 months. RESULTS: Immediately after surgery, we observed a significant overcorrection in the treated meridian in all patients. Then, a gradual decrease of the refractive effect was noticed, since the average refractive astigmatism was +0.25 +/- 1.23 D at 6 months and +1.15 +/- 0.86 at 12 months after surgery. At 1 month after surgery, the mean shift in the cylinder axis was 83.75 degrees +/- 8.82 degrees and 12.08 degrees +/- 12.33 degrees at the 1-year examination. Uncorrected visual acuity was 20/40 or better in all patients 1 year after surgery. We did not observe severe corneal complications, such as irregular astigmatism or delayed epithelial wound healing. CONCLUSION: Hot needle sectoral thermal keratoplasty appears to be safe and partially effective in reducing hyperopic astigmatism, but considerable postoperative regression may occur.

Adult↗
PubMedDate not supplied

Angle-fixated anterior chamber phakic intraocular lens for myopia of -7 to -19 diopters.

PURPOSE: To assess the safety and efficacy of a second generation, anterior chamber phakic intraocular lens (Baikoff Model ZB5M) in patients with high myopia. METHODS: One hundred and twenty-one patients (134 eyes) with myopia of -7.00 to -18.80 D were implanted with the ZB5M lens and followed for 18 to 52 months; the number of eyes evaluated was: 6 months (104 eyes), 1 year (91 eyes), 18 months (78 eyes), 2 years (68 eyes), and 3 years (35 eyes). RESULTS: Postoperative spherical equivalent refraction averaged -1.00 D and the error in refractive correction (achieved minus intended) averaged -0.40 D during the first 2 years, increasing -to -1.30 D refraction and -0.60 D error in refractive correction at 3 years. At 2 years, approximately 40% of eyes had a spherical equivalent refraction within +/-0.50 D, and 65% within +/-1.00 D. The uncorrected distance visual acuity was 0.048 at baseline and 0.5 at 3 years; near visual acuity was 0.21 at baseline and approximately 0.7 over the 3 years of follow-up. Spectacle-corrected distance visual acuity at baseline was 0.54; it improved to 0.7. Near visual acuity was 0.65 at baseline and it improved to approximately 0.75. Endothelial cell counts in the central and peripheral cornea were reduced by an average 3.3% at 6 months, declining an additional 1% to 2% over the remaining follow-up period. Regression analyses indicated that most of the endothelial cell loss was due to surgery. Additional complications included halos/glare in 37 of 133 eyes (27.8%) and iris retraction with pupillary ovalization in 30 of 133 eyes (22.6%). The intraocular lens was exchanged in four of 133 eyes (3.0%) and removed in three of 133 eyes (2.3%), the latter because of halos (one eye) and a flat anterior chamber with severe inflammation (two eyes). CONCLUSIONS: Implantation of the Baikoff ZB5M lens in the anterior chamber of phakic eyes significantly reduced high myopia and produced a stable refractive outcome over the 3 years, accompanied by marked improvement in uncorrected distance visual acuity and minimal, non-progressive damage to the corneal endothelium. Frequent complications included pupillary ovalization and halos/glare. Improvements in accuracy of IOL power calculations are needed.

Adult↗
PubMedDate not supplied

[Lamellar graft in the treatment of herpes simplex ocular (author's transl)].

72 lamellar grafts for herpes simplex ocular infections have been performed. A retrospective study tries to specify the indications. Penetrating graft is the best for leucomae. The most difficult choice occurs with active herpetic disease. With lamellar grafts good results are obtained in stromal keratitis without deep involvement (visual acuity is 0.2 or more in 75 per cent of cases). When endothelio-uveal involvement, prognosis becomes uncertain in any type of keratoplasty: the authors think that the best method is to perform surgery after a few months of inactive disease.

Corneal Opacity↗
PubMedDate not supplied

Damage to the corneal endothelium from anterior chamber intraocular lenses in phakic myopic eyes.

The use of minus power anterior chamber intraocular lenses to correct myopia in phakic eyes has been demonstrated previously to produce a more accurate and predictable correction than corneal refractive surgery techniques. We have examined 15 such eyes by specular microscopy and 10 such eyes by Scheimpflug slit-lamp micrography. One year after surgery, in 5 (36.3%) eyes, there was a decrease of more than 20% in the central endothelial density. Paracentral endothelial damage was present in 13 eyes (86.6%). On the specular micrograph, this damage appeared as an overall decrease in the number of the cells, abnormal cell shape with marked pleomorphism, dark zones, and acellular zones that corresponded to endothelial defects. The slit-lamp anterior segment measurements showed a distance between the edges of the IOL optic and the endothelium which ranged from 0.71 to 1.50 mm. We discuss the criteria for intraocular lens removal.

Adult↗
PubMedDate not supplied

[Selection of a herpes simplex mutant virus of weak pathogenicity, sensitive to acyclovir and not susceptible to reactivation in vivo].

From a KOS herpes simplex virus strain prepared in VERO cells we have been able to obtain after several exposures to increasing concentrations of trifluorothymidine, four resistant mutants. Among these strains, 31 T mutant was a TK-altered strain of low pathogenicity, sensible to acyclovir and did not induce recurrences. These properties might allow the use of such a strain as a living attenuated antiherpetic vaccine.

Acyclovir↗
PubMedDate not supplied

The surgical treatment of high myopia: comparison of epikeratoplasty, keratomileusis and minus power anterior chamber lenses.

Seventy high myopic eyes (-8.00 to -28.00 diopters) with epikeratoplasty (n = 29), myopic non-freeze keratomileusis (n = 26) or minus power anterior chamber intraocular lenses in phakic eyes (n = 15) were operated by two surgeons and were evaluated retrospectively. Results are reported at the 6-month postoperative interval. Eyes treated with epikeratoplasty had an average preoperative spherical equivalent of the cycloplegic refraction of -17.80 D (range -12.00 to -28.00 D). At 6 months, 66.6% of eyes were within 3 D of emmetropia and 7.4% of eyes had an uncorrected visual acuity of 20/40 or more. Average preoperative spectacle visual acuity was 20/50 (0.39); it was 20/50 (0.37) at both 6 and 24 months. Between 6 and 24 months, 32.2% of eyes had a change in refraction of 1.00 D or more. Two lenticules were removed. Eyes treated with non-freeze keratomileusis had an average preoperative refraction of -10.0 D (range -8 to -15 D). At 6 months, 61.5% of eyes were within 3.00 D of emmetropia and 30.7% of eyes had an uncorrected visual acuity of 20/40 or better. Average preoperative spectacle visual acuity was 20/30 (0.67), and 6 and 12 months afterward it was 20/30-20/40 (0.57) and 20/30 (0.66) respectively. Between 6 and 12 months, 8.3% of eyes, had a change in refraction of 1.00 D or more. Eyes treated with minus power anterior chamber lenses had an average preoperative refraction of -17.30 D (range -12.50 to -20.00 D).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMedDate not supplied

[Comparison of phacoemulsification and manual extracapsular extraction of the lens].

In a prospective study, 60 patients have been operated on for cataract either with phacoemulsification or with manual extracapsular extraction of the lens. All the patients received the same type of PMMA intraocular lens. Visual results and incidence of angiographic cystoïd macular edema were similar in both groups. The mean endothelial cell loss was 10.7% with phacoemulsification and 7% with manual extracapsular extraction.

Aged↗