[In vivo confocal microscopy evaluation of corneal changes induced after LASIK using the IntraLase femtosecond laser technique]. / Evaluation en microscopie confocale des modifications morphologiques cornéennes induites après LASIK et découpe du volet stromal par laser femtoseconde IntraLase.

PURPOSE: To assess stromal modifications occurring after IntraLase femtosecond laser for laser in situ keratomileusis (LASIK) using the Heidelberg retina tomograph II/Rostock cornea module. MATERIAL AND METHODS: Twelve eyes from six patients were examined using the Heidelberg retina tomograph II cornea module after IntraLase femtosecond laser: ten eyes were examined at 1 week and 2 months after laser surgery, including four eyes examined at day 1, and two eyes examined at day 2. Morphological modifications of the corneal stroma, flap interface, and flap margin were evaluated at these different times and compared with the mechanical microkeratome interfaces of five patients (ten eyes), using the same technique at the same periods after the surgical intervention. RESULTS: Evaluations at days 1 and 7 showed simultaneous depletion and activation of keratocytes on both sides of the interface. We also observed some brightly reflecting particles together with scattered, less bright dots, from day 7 and increasing after 2 months. Some clinically visible deposits at the level of the interface were observed at the periphery of the flap at day 1 and could represent cell-degradation products. With confocal microscopy, they appeared as homogeneous reflective deposits with a larger size than that of particles; they had decreased at month 2. The flap margin appeared microscopically as a very clear-cut edge, including epithelial cells, while those performed with a mechanical microkeratome appeared more like a poorly limited fibrotic scar. We also observed a secondary fibrotic reaction at month 2, adjacent to the still well-defined IntraLase flap edge. CONCLUSION: This study showed substantial morphological similarity between the interfaces obtained with femtosecond laser and mechanical microkeratome. The discovery of brightly reflecting particles in the IntraLase interface goes against the hypothesis of the metallic origin of these deposits. The flap margin microscopically looked extremely well delimited, but seemed to provoke an adjacent secondary fibrotic reaction, both microscopically and macroscopically, greater at 2 months than after a mechanical microkeratome cut.

[Excimer laser photorefactive keratectomy retreatment following photokeratectomy under-correction]. / Retraitement à l'aide du laser excimer de surface des sous-corrections dans les suites de photokératectomies réfractives.

PURPOSE: Results of excimer laser photorefractive keratectomy are well accepted for the correction of low to moderate myopia. However, the occurrence of a regression is still a frequent complication. The purpose of the present study is to evaluate the interest and risk of excimer photorefractive keratectomy retreatment of eyes that underwent a regression of the refractive effect. PATIENTS AND METHODS: A retreatment was achieved in 27 eyes of 22 patients. This reshaping was required because of either an expected undercorrected initial treatment, either a regression of the refractive effect of the first photorefractive keratectomy that did not respond to the topical steroid therapy. As we used two different types of excimer laser to achieve the retreatments, we formed two subgroups. In the first sub-group, 13 eyes were retreated with an Excimed (Summit), and in the second one, that included 14 eyes, a laser EC5000 (Nidek) was used. The delay between the first procedure and the retreatment was 16.38 +/- 7.56 months in the first sub-group and 29.85 +/- 13.09 months in second one. The mean attempted correction for the reshaping was -3.01 +/- 1.25 diopters in the first sub-group and -1.63 +/- 0.80 diopters in the second one. RESULTS: No specifical problem was encountered during the retreatment. Specifically, we did not observe any decentring. By the third post-operative month, patients recovered a mean uncorrected visual acuity of nearly 7/10 in both sub-groups. This mean uncorrected visual acuity did not regressed during the follow-up. In addition, the mean post-operative refraction was 0.11 +/- 0.78 diopters in the first sub-group and -0.20 +/- 0.59 diopters in the second, three months after reshaping. The final refraction was -0.15 +/- 0.30 dioptres in the first sub-group and -0.70 +/- 0.62 dioptres in the second one. Nine eyes exerienced a regression during the follow-up period, from which three responded to the topical steroids. These regressions occurred in 4 eyes from the first sub-group and 5 of the second one. No other complication were observed. DISCUSSION: Although there is a aggreement about the efficacy of excimer laser in the treatment of low or moderate myopia, regressions of the refractive effect is not unfrequent. It can warrant a reshapping. Our results demonstrate the simplicity and the predictive value of excimer laser in the retreatment of these regressions after photorefractive keratectomy. This method seems more accurate than radial keratotomy. CONCLUSION: Excimer laser retreatment is highly effective in the correction of undercorrection after a previous procedure of photorefractive keratectomy, especially when the attempted correction of the initial treatment was under -6 diopters.

[Results of treatment of undercorrections of radial keratotomy by Excimer laser]. / Résultats du traitement des sous-corrections de kératotomie radiaire au laser Excimer.

Photorefractive keratectomy (PRK) was performed with Excimer Laser after undercorrected radial keratectomy in 21 eyes of 15 patients (maximum 8 incisions, 3 mm optical zone). There was at least a 6-month interval between the two procedures. At the time of PRK, the mean age of the patients was 31 years and the mean spherical equivalent -2.3 D. Mean follow-up after PRK was 7.5 months; 10 eyes were followed for more than one year. Quite satisfactory results were obtained since PRK was effective in 88% (eyes with uncorrected visual acuity of 20/40 or better); predictability at +/- 1 D was 89%. Stable refractiveness was achieved at 3 months. The procedure is safe: there was no loss of best corrected visual acuity nor haze at one year. Other means of treating for undercorrection after refractive keratectomy were discussed in comparison with this technique.

[Posterior chamber implantation in black Africa. Apropos of 150 cases with an 18 months follow-up]. / L'implantation de chambre postérieure en Afrique noire. A propos de 150 cas suivis pendant 18 mois.

The purpose of this article is to report our study of 150 cases of posterior chamber implantations carried out at the Hôpital Principal de Dakar between 1988 and 1991. We report the specific difficulties of such operations in black Africans and their complications and follow-up. At the end of this study, after observations over an eighteen month period, we noticed a visual acuity of more than 20/30 for 105 patients (70%) and a secondary cataract in 22 cases (14.6%). Despite less favourable material conditions, we think that such an operation can perfectly be made in Africa and that it gives quite acceptable results.

[Clinical results of photo-refractive keratectomy. Preliminary study with 57 eyes]. / Résultats cliniques de la photo-kératectomie réfractive. Etude préliminaire sur 57 yeux.

The authors report their personal experience of Photo-Refractive Keratectomy (PRK) with an Excimer Laser based on the study of 57 sighted eyes, 24 with more than six months and 11 with more than one year of follow-up. The initial myopia ranged from -1 to -13 D with a spherical average equivalent of -6.36 D. The photo-ablations, performed with the Excimer of the Summit Company, ranged from 3.7 to 5 mm of diameter and 16 to 76 mu in depth. Results are reported overall and for sub-groups of myopia (A < or = -3 D, -3 D < B < or = -7 D, -7 D, < C). They were satisfactory since at one year 45% of eyes obtained a visual acuity without correction > or = 5/10 and 64% of eyes were within one dioptre of emmetropia; stability of refraction from six months to one year is close to 80%; safety was good since no patient has lost a line of best spectacle corrected visual acuity at one year and we only found one case of haze at 1+ without visual loss. These encouraging results lead the authors to pursue their study and to include new patients to obtain larger groups in order to establish statistically significant differences for parameters such as age, sex, myopia, keratometry, depth and optical zone of photo-ablation.