2. Background Aniesekonia may limit the effectiveness of conventional optical correction in prevention/treatment of amblyopia. Co-existent medical conditions – esp developmental / cognitive may prevent / limit the use of conventional treatment techniques. PRK and LASEK have been shown to be safe in children and present a useful alternative in the above situations.

3. Study Aims To examine the long term visual outcomes in children after surgical refractive correction and evaluate differences in outcomes between those who had PRK and those who had LASEK.

4. Methods Retrospective Case Series Patients treated with PRK or LASEK based solely upon time of presentation (ie. Non randomized).

5. Methods Inclusion Criteria ‘end stage treatment failures in whom traditional methods of optical correction were not successful’ Unable to wear glasses and / or contact lenses And > 3.0D of anisometropic myopia And / or more than -5.0D of bilateral myopia – ‘chosen as representing a point at which visual blurring and / or anisometropia, when not corrected would have substantial impact on the child’s ability to function in his or her environment’ – All patients were included regardless of co-morbid medical diagnoses. – Conventional treatments such as atropine and patching continued.

6. Methods Refractive Methodologies – General anaesthesia – Camellin-Shahinian LASEK nomogram. Myopia <8.0D : 10% reduction off spectacle plane sphere -8.0D to -10.0D 15% off >-10.0D 20% off.

7. Methods Primary Outcome Measures: – Refractive Error – Corneal Clarity / Haze (graded 0 to +3) – BCVA Other outcomes – Stereopsis (Titmus, Lang1, Frisby) – Macular / extramacular fusion (Worth 4 dot)

8. Results 56 eyes of 39 children treated. 27 eyes PRK, 29 eyes LASEK Mean age 6.5 yrs (R 1.0 to 17.4 years) Mean follow up 5.15 years (R 3.5-7.8 yrs)

9. Results Refractive Error Range treated was large (+1.75D to -27.0D) – At last follow up 77% within 3 dioptres of target SE. – ‘Although the SE remained relatively stable, by 2 years postoperatively, laser myopic regression was noted in some children. Twenty-four eyes (43%), 13 (54%) in the PRK group and 11 (46%) in the LASEK group, required a second laser procedure.’ – Secondary Procedure mean at 26 months. – Mean SE after second treatment -1.73D

10. Results Refractive Error

11. Results Corneal Clarity / Haze – Not significant in any child.

12. Results BCVA – 28 of 39 children could have VA measured – 42.9% (12)had improved BCVA – Remainder unchanged – None were worse. – 5 of 28 had >5 lines improvement at 12 months.

13. Results Stereopsis – Steropsis and fusion did seem to improve with treatment.

14. Comments Small study – only 56 eyes. Retrospective Limited descriptive statistics only. No measures of statistical significance. Limited comparison between two modalities. Non randomised. No control or sham treatment group. Single centre

15. Comments Despite claims of relatively stable SE, almost a half of patients suffered myopic regression that required enhancement at around 2 years post initial treatment. Seems relatively safe – whilst significant numbers suffered haze, no one was worse off

16. Comments Did seem to be improvements in BCVA, SE and stereopsis/fusion. Though conventional treatments such as patching etc. continued. Need to be examined in setting of RCT to bear out these findings. Longer term follow up also required – eg incidence of keratectasia, keratoconus