Laser Refractive Modeling of the Cornea: New Perspectives

The scientific and practical significance of the development of new approaches to refractive modeling of the cornea by laser radiation is beyond doubt.

The purpose of this study is to develop new methods of refractive modeling of the cornea based on the saturation of the stroma with riboflavin and exposure to radiation from an argon-fluorine excimer laser.

Experimental (20 porcine eyes, 90 rabbit eyes) and clinical studies on photorefractive and phototherapeutic operations with saturation of the corneal stroma with riboflavin (610 operations) were analyzed. A quick transition to energy densities below the ablation threshold without additional calibrations was carried out a “Microscan Visum-500” excimer laser (Optosystems, Russia). The benefits of refractive keratomodeling using an argon-fluorine excimer laser in ablative and subablative modes after riboflavin saturation of the stroma have been demonstrated in both experimental and clinical trials. The accuracy of refractive ablation was unaffected by isotonic 0.25 percent riboflavin solution, which also inhibited the detrimental effects of generated secondary radiation on keratocytes and nerves. As a result, the aseptic inflammatory response was reduced, as was the likelihood of developing irreversible fibroplasia. Ablation with riboflavin caused a damped crosslinking action, which improved the thinned cornea's photoprotective and strength qualities. When energy densities were supplied below the stromal ablation threshold, a refractive keratomodeling effect was discovered. The size of this refractive impact was determined by the overall radiation dose as well as the topography of the affected region. This method allowed laser-induced refractive keratomodeling to be performed without ablation of the corneal stroma.

After saturation of the stroma with riboflavin, refractive modeling of the cornea using an argon-fluorine excimer laser in ablative and subablative modes offers up new options in laser correction of ametropia.