Abstract
Purpose: :
To study and analyze intraocular fluids and surface of intraocular lenses (IOLs) in normal eyes donated for corneal transplantation after long-term non-complicated cataract surgery.
Methods: :
Ocular surface, intraocular fluids and IOLs from 30 donated eyes not suitable for corneal transplantation were studied. Eyes were preserved with antibiotic solution (penicillin, streptomycin and amphotericin B) and rinsed with saline solution. Afterwards, ocular surface was decontaminated by different methods (povidone-iodine 5%, 2.5%, 0.5%, and clorhexidine 0.05%) and their effectiveness was evaluated by conventional microbiological cultures for bacteria and fungi detection. Samples of aqueous humor (100 - 200 µl) and vitreous (500 µl) were collected on sterile conditions and cultured on different microbiological media. IOLs (n=30) were explanted, immediately fixed in paraformaldehyde 2% + glutaraldehyde 2.5% solution, dehydrated in increasing concentrations of ethanol and prepared for scanning electron microscopy (SEM).
Results: :
Ocular surface microorganisms were isolated in 15 eyes (50%) before decontamination. The mean effectiveness of decontamination was 80%, ranging from 50% (povidone-iodine 0.5%) to 100% (povidone-iodine 2.5%) depending on the method. Microorganisms were not detected in any of the intraocular fluid samples. Most IOLs analyzed by SEM showed cellular material and debris on their surface, mainly epithelial aggregates and lens fibers. Bacterial biofilms were suspected in 33.4% (n=10) IOLs surfaces studied. Isolated or aggregated coccoid structures (about 1 µm) were observed on the surface of IOLs made of silicone (n=1; 100%), acrylic hydrophobic (n=2; 50%), PMMA (n=5; 31.3%), and acrylic hydrophilic (n=2; 22.2%) biomaterial.
Conclusions: :
Results suggest the possibility of bacterial biofilm formation on the surface of IOLs explanted from normal eyes after long-term non-complicated cataract surgery.
Keywords: intraocular lens • microscopy: electron microscopy • cataract