[Morphological changes of cornea in children with hyperopia in the immediate and remote postoperative period after laser keratomieleusis according to confocal microscopy data]. / . Morfologicheskie izmeneniia rogovitsy u detei s gipermetropiei v rannie i otdalennye sroki posle lazernogo keratomileza po dannym konfokal'noi mikroskopii.

Studying morphological changes of cornea in the remote postoperative period is becoming increasingly relevant with refractive surgeries being adapted for children. PURPOSE: comparative analysis of keratocyte density and hystomorphologic changes of cornea after laser in situ keratomieleusis (LASIK) and femtosecond laser-assisted LASIK (FS-LASIK) in children with hyperopia. MATERIAL AND METHODS: 109 patients aged 6-17 years in 2 groups were examined with 'Confoscan-4' confocal microscope. RESULTS: In comparison with initial data, keratocyte density decreased in the immediate postoperative period after FS-LASIK and LASIK in average by 17.09%, 64.31% and 12.2% in the corneal flap, directly in the laser influence zone (interface) and in the retroablation zone respectively. After 5 years, keratocyte density decreased in the corneal flap, interface zone and retroablation zone by 12.01%, 48.71% and 8.06% respectively in comparison with initial data. A circular scar at the flap edge was left after FS-LASIK; keratocyte density in the corneal flap and in the interface zone was in average 8.9% and 15.28% higher respectively, and twice more subepithelial nerves were noted compared to LASIK. CONCLUSIONS: In the remote postoperative period keratocyte density in the corneal decreased in average by 43% after FS-LASIK and by 46% after LASIK in comparison with initial data. No changes were seen in the morphologic state of the cornea outside the influence zone. Both the technologies are safe, however keratocyte density and the number of subepithelial nerves are higher in the cornea flap and in the interface zone after FS-LASIK; corneal stability is assured by a circular scar formed at the flap edge.

[Analysis of corneal biomechanical changes after femtosecond laser-assisted laser in situ keratomileusis in children with hyperopic anisometropia]. / Analiz biomekhanicheskikh izmenenii rogovitsy posle lazernogo intrastromal'nogo keratomileza s femtolazernym soprovozhdeniem u detei s gipermetropicheskoi anizometropiei.

AIM: to analyze corneal hysteresis (CH) and corneal resistance factor (RF) readings obtained with the Reichert Ocular Response Analyzer (ORA) before and after hyperopic femtolaser-assisted laser in situ keratomileusis (FS-LASIK) in children with anisometropia as well as to establish factors that may cause changes in these parameters. MATERIAL AND METHODS: CH and RF were evaluated before and 1.5 years after FS-LASIK performed on amblyopic eyes of 28 patients aged 6-14 years. Preoperatively, there was a correlation between CH and RF (r=0.41, p=0.03). No correlation was found between CH and age (r=-0.02, p=0.82) or between CH (r=0.00, p=0.98), RF (r=0.04, p=0.83), and cornea thickness. RESULTS: The mean preoperative CH was 12.56±1.21 mmHg, RF 12.31±1.57 mmHg. Postoperatively, a statistically significant change occurred to both CH (by 0.97±1.51 mmHg, p=0.002) and RF (by 1.42±1.55 mmHg, p=0.000). No correlation was found between CH before and after surgery (r=0.11, p=0.57) as well as between the ablation depth and changes in CH (r=0,04, p=0.83) and RF (r=0.21, p=0.28). Regression analysis showed that the extent of CH (r2=0.52, p=0.00) and RF (r2=0,48, p=0.00) changes was closely related to their preoperative values. CONCLUSION: The statistically significant relative change in CH and RF after hyperopic FS-LASIK was 8% and 12%, respectively. CH and RF changes correlated with their preoperative values, but not with the ablation depth or cornea thickness.