[Apoptosis and the ocular surface]. / Apoptose et surface oculaire.

Apoptosis, or programmed cell death, is an active phenomenon that plays a major role in most mechanisms of regulation, differentiation and wound healing. Mostly studied in the retina, apoptosis is also extensively involved in the anterior segment, especially the ocular surface. Apoptosis of keratocytes is a rapid phenomenon following excimer refractive surgery. Any epithelial aggression stimulates a series of mechanisms leading to death of deep keratocytes. The role of epithelial cell mediators may explain the superiority of LASIK compared to PRK in terms of functional rehabilitation. Conjunctiva is also a major site in which inflammation and apoptosis are combined. Proinflammatory cytokines may both amplify immune reactions and stimulate epithelial apoptosis, which is most likely to result in elimination of injured tissues. Toxic drugs also play a major role and iatrogenic apoptosis should be avoided as much as possible, especially by eliminating preservatives from eyedrops, most of which use both proinflammatory and proapoptotic agents.

[Corneal stromal changes after LASIK]. / Aspect en microscopie confocale des modifications morphologiques cornéennes induites par le LASIK.

PURPOSE: To assess stromal modifications after laser in situ keratomileusis (LASIK) for myopia using in vivo confocal microscopy. METHODS: Thirteen eyes from 10 patients were examined before surgery and at days 8 and 30 after surgery using an in vivo confocal microscope coupled with a Z-Scan system. Stromal morphological changes, keratocyte density, flap thickness, and subclinical haze were evaluated and compared at different time points. RESULTS: Microfolds at the Bowman's layer were found in 55%, eyes as well as variable reflectivity particles located at the interface level in all postoperative examined eyes. The mean flap and activated-cell area thicknesses were respectively, 101+/-28 micrometer and 50.5+/-14 micrometer with a significant negative correlation (r=-0.89, p=0.01). The intensity of the added peak (47.3+/-8.6% scattered light), corresponding to the subclinical haze, as measured by Z-Scan, was also negatively correlated with the flap thickness (r=-0.89, p=0.01). CONCLUSION: This study confirms the presence of microfolds and particles at the interface level as subclinical complications. Evaluating the keratocytic activation by confocal microscopy can lead to a better understanding of corneal wound healing after LASIK and can help to improve the techniques. The flap thickness seems to be involved in the cellular activation induced by LASIK.

[Influence of corneal refractive surgery on the lacrymal film]. / Influence de la chirurgie réfractive cornéenne sur le film lacrymal.

Functional and clinical signs of ocular surface involvement are observed after corneal refractive surgery (LASIK or PRK) and are evocative of dry eye syndrome. The surgical process induces a total or partial section or abrasion of the corneal-sensitive nerves. This anatomical consequence of surgery is responsible for a lachrymal dysregulation with reduced tear production. Neither technique is currently able to demonstrate its superiority in preserving the lachrymal secretion. These postoperative findings should be clearly explained to patients before surgery and discomfort should be prevented with artificial tears and/or punctual plugs for 1 to 6 months after surgery.

[Persistence of the pupillary membrane. Apropos of 3 cases]. / Persistance de la membrane pupillaire. A propos de 3 cas.

Persistent pupillary membrane has in most cases no functional consequence. Nevertheless, a thick membrane involving visual axis sometimes requires surgical removal. We describe three cases of this surgery with pathologic examination and functional results.

[Severe bilateral capsulorhexis contraction after cataract surgery in myotonic dystrophy: a case report]. / Capsulophimosis sévère et bilatéral survenant après chirurgie de la cataracte chez un patient présentant une myotonie dystrophique de Steinert. A propos d'un cas.

INTRODUCTION: The Authors report the case of a 50-Year-old man with myotonic dystrophy, who developed severe bilateral capsulorhexis contracture after uneventful cataract surgery. OBSERVATION: Phacoemulsification was performed in both eyes with implantation of intraocular lenses. The patient came to complain of decreased vision in both eyes (4/10 Parinaud 4). Visual acuity initially improved after surgery to 8/10 P2 in each eye. After 7 months for the right eye and 3 Months for the left eye, the patient presented with dramatically reduced vision, caused by a severe capsulorhexis contracture. Anterior capsulotomies with the Nd:YAG laser were performed in both eyes to treat this complication. It was sufficient on the left eye but the right eye required a surgical anterior capsulectomy to remove the IOL and the bag and put in an Artisan lens. DISCUSSION: Capsulorhexis contracture results from fibrous metaplasia of lens epithelial cells from the anterior capsule. Myotonic dystrophy appears to predispose to the development of severe capsulorhexis contracture after phacoemulsification.

Evaluation of corneal stromal changes in vivo after laser in situ keratomileusis with confocal microscopy.

PURPOSE: To assess by in vivo confocal microscopy the modifications of the corneal stroma after laser in situ keratomileusis (LASIK) for myopia. DESIGN: Nonrandomized comparative (self-controlled) trial. PARTICIPANTS: Sixteen eyes of 13 patients were examined before surgery and at days 8, 30, and 90, and 9 eyes were examined at 6 months postoperatively using an in vivo confocal microscope. TESTING/INTERVENTION: Stromal morphologic changes, keratocyte density, flap thickness, and subclinical haze were evaluated and compared at different time points. LASIK was performed with a Flapmaker microkeratome (Solan Ophthalmic products, Jacksonville, FL) and a Lasersight LSX excimer laser (LaserSight Technologies Inc., Winter Park, FL). MAIN OUTCOME MEASURE: Confocal microscopy results. RESULTS: Microfolds at the Bowman's layer were found in most eyes, as well as variable reflectivity particles (pa) located at the interface level in all eyes examined postoperatively. The density of these particles significantly decreased with time with, respectively, 504 +/- 101 pa/mm2 at day 8 and 380 +/- 111 pa/mm2 at day 30 (P = 0.003), 332 +/- 100 pa/mm2 at month 3 and 312 +/- 40 pa/mm2 at month 6. The mean flap and the activated-cells area thicknesses were, respectively, 102 +/- 26 microm and 61 +/- 19 microm and showed significant negative correlation (P < 0.0001). The intensity of the added peak (47.3 microm 8.6%), corresponding to the subclinical haze, realized by Z-scan measure, was also negatively correlated with flap thickness (P = 0.01). Keratocyte (k) density quantified in the posterior stroma significantly increased from day 0 (480 +/- 67 k/mm2) to day 8 (701 +/- 41 k/mm2, P < 0.0001 compared with day 0) and day 30 (917 +/- 143 k/mm2, P = 0.0006, compared with day 0) but significantly decreased at 3 months postoperatively (597 +/- 56 k/mm2, P < 0.0001 compared with day 30) to reach the initial level at month 6 (502 +/- 41 k/mm2, nonsignificant compared with day 0). There was no correlation between preoperative or postoperative spherical equivalent and the density of particles, keratocytes, and the haze intensity. CONCLUSIONS: This study confirms the presence of microfolds and particles at the interface level, as well as subclinical impairment. Evaluation of keratocyte density constitutes a major contribution of confocal microscopy toward an understanding of the keratocyte response to corneal wound healing after corneal refractive surgery. Moreover, flap thickness seems to be involved in the postoperative cellular activation with a higher response when thin.