Children may become frightened as the clinician approaches closely, during direct ophthalmoscopy and co-operation could be lost. Also, children often look at the ophthalmoscope light and track it as the clinician moves, allowing examination of the macula but not the optic disc. Furthermore, the field of view is small and the magnification is more than is necessary. This will prevent the examiner from seeing the ‘big picture’. To avoid these difficulties the direct ophthalmoscope can be used with a 20D condensing lens, the type used with head mounted binocular indirect ophthalmoscopes. This combination provides a moderately magnified and wider angle, view of the posterior pole and avoids the close proximity between the patient and clinician. The technique has been noted for providing a good view of the retina through a small pupil when dilation is contraindicated.
The technique allows stereoscopic, wide-angled, high-resolution views of the fundus and overlying vitreous. Its optical principles and illumination options allow for visualisation of the fundus regardless of high ametropia, hazy ocular media, or central media opacities.
Negative powered auxiliary lenses in conjunction the slit-lamp biomicroscope can be used to view the vitreous and retina and in particular the optic disc and the macula. For clinicians with some level of binocularity a binocular direct image is viewed. The use of the slit-lamp biomicroscope allow...
All types of diagnostic contact lenses have a high minus power which produces an upright virtual image which is not laterally reversed. Contact lenses also have an advantage in that the examiner's view of the retina is not interrupted by the patient's blink reflex, although the use of contact len...
