[The aqueous humor-vitreous body barrier and the blood-aqueous humor barrier after YAG laser capsulotomy in capsular sac vs ciliary sulcus fixation of the intraocular lens].

UNLABELLED

An intact posterior capsule between aqueous and vitreous may act as a barrier to substances of low and high molecular weight, e.g., prostaglandins, hyaluronic acid, or the angiogenic factor. After phacoemulsification followed by posterior YAG capsulotomy, an increased diffusion rate of such molecules into the vitreous and increased permeability of blood aqueous barrier (BAB) may occur. These barriers were quantified in eyes that underwent YAG capsulotomy after sulcus or intracapsular IOL implantation in order to determine the safest surgical procedure with respect of maintenance of these barriers.

PATIENTS AND METHODS

Between 2 to 6 h after topical fluorescein application, the time-dependent decrease in dye concentration ratio between aqueous and anterior vitreous leads to the diffusion rate D(av) [10(-3)min-1] between aqueous and vitreous; D(av) was evaluated fluorophotometrically before and 3 weeks after capsulotomy (3 to 5 mm) in human eyes of each group. In order to quantify BAB function, aqueous laser flare was measured in eyes with sulcus and capsular fixation of IOL before, 3 h, and 3 weeks after YAG capsulotomy.

RESULTS

After YAG surgery D(av) increased 2.7-fold (P < 0.001) in eyes with a sulcus implant compared to the values obtained in the group that had an intracapsular PCL. Aqueous laser flare was increased to 140% (P < 0.001) in eyes with sulcus fixation and to 95% (P < 0.001) in eyes with capsular fixation of PCL. Laser flare values became normal 3 weeks after laser treatment (P > 0.05).

CONCLUSION

Intracapsular PCL implantation more effectively maintains the protective aqueous vitreous barrier and BAB after posterior capsulotomy than sulcus implantation. This possibly reduces the incidence of cystoid macular edema (diffusion of prostaglandins), retinal detachment (loss of hyaluronic acid of the vitreous), endophthalmitis (spread of bacteria) or rubeosis iridis (angiogenic factor) after YAG capsulotomy.