Abstract
Purpose: :
To evaluate accommodation and binocular vision in symptoms after LASIK surgery and effect of glasses corrected those disorders and vision therapy (VT).
Methods: :
29 patients (30.52 ± 7.9 yrs) who significantly feel symptoms after LASIK surgery were examined about symptoms, refraction, accommodative lag and binocular vision. Lateral heterophoria and vertical heterophoria were measured with Howell phoria card and Maddox rod. Accommodative lags were measured by MEM (monocular estimated method) at 40 cm. The prism, addition power or/and VT were prescribed to reduce symptoms. Questionnaires were used to evaluate patients’ symptoms before and after wearing the glasses and/or VT.
Results: :
Before LASIK surgery all subjects had no significant symptom. After LASIK surgery the most subjects felt poor concentration with near task (72.4%) and/or light spread and sensitivity at night (31.0%). The other subjects’ symptoms were dryness, dizzy, intermittent diplopia, tinnitus, vomiting, shaking of fluorescent light and/or different illumination between right and left eye (55.2%). Poor concentration at near was related to either binocular vision or both binocular and accommodation. Among 15 subjects of binocular vision disorders at the near 13 had over exo 5 PD (exo 8.09 ± 3.11 PD) phoria and /or over 1 PD(1.2±0.45) vertical phoria and one for eso 2 and 1 PD vertical phoria and the other one for exotropia 18 PD. The other 6 subjects showed over 0.50D (1.04 ±0.41D) accommodative lag and exo 4.07±2.89D at 40cm. Other symptoms may relate to distance and near phoria and corneal surface, pupil diameter ect. When prisms or/and addition power glasses were given, 25(86.2%) of 29 subjects showed reducing the symptoms 47-82% (p<0.001).
Conclusions: :
After LASIK surgery the major factors related to produce symptoms were accommodative and binocular vision disorders. The symptoms were significantly reduced by prescribing glasses of prism, addition power or/and VT.
Keywords: refractive surgery: LASIK • binocular vision/stereopsis • refraction