Screening of refractive errors, according to the defined protocols with required instruments (Snellen charts, refraction boxes with trial frames, autorefractometer, retinoscope
, ophthalmoscope and hand-held slit lamp etc.) and logistics by a team of optometrists supervised by an ophthalmologist was managed in the schools.13 Visual Acuity (VA) of the study subjects was evaluated with the Standard Snellen Chart placed at a distance of six meters.
After 21 days of lens treatment, the refractive state was determined by two optometrists using a streak retinoscope
, and the eyes of the guinea pigs with a mean value more than -6.0D were included in this study.
It is worthwhile including a measure of accommodative accuracy in those patients presenting with visual complaints at near; this can easily be done with a retinoscope
using the MEM or Nott methods, details of which can be found elsewhere.
Objective exam to "measure the refractive power of the eye by interpreting the light reflected from its retina when illuminated with the retinoscope
All participants underwent a comprehensive ophthalmologic examination consisting of visual acuity assessment (best corrected visual acuity [BCVA]), intraocular pressure (IOP) assessment, slit-lamp biomicroscopy combined with retinoscope
, and fundus fluorescein angiography (FFA).
Cyclopentolate drops were used to dilate the pupil of the eye and relaxing the ciliary muscles and the refractive status was measured after 1 hour by a retinoscope
and after 3 days when the mydriasis effect released, we perform the subjective refraction based on retinoscopy results.
Refraction is performed in a semi dark room by using retinoscope
with the examiner at a distance of 0.75 meters and a +1.50 dioptre lens in the trial frame.
This was carried out by a single investigator, using a hand held retinoscope
(HEINE Optotechnik, Herrsching, Germany) and trial lenses.
In this method, a specific eyedrop is applied to the eyes to relax the focusing muscles, and then refraction is checked after 30-40 minutes using a handheld instrument called a retinoscope
. This is the most accurate way of determining the proper eye degree of the child.
Refractive error was assessed with autorefractometer and retinoscope
prior to visual acuity examination.