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.

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.

Methods

• Retrospective Case Series

• Patients treated with PRK or LASEK based solely upon time of presentation (ie. Non randomized).

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.

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.

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)

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)

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

Results

• Refractive Error

Results

• Corneal Clarity / Haze– Not significant in any child.

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.

Results

• Stereopsis– Steropsis and fusion did seem to improve with

treatment.

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

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

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