Myopia - Ocualr examination or Investigation 4/5

A. Visual Acuity: 

• Both unaided distance and near visual acuities should be measured;
• Because of the correlation of unaided distance visual acuity with the degree of myopia. 
• When the patient regularly wears an optical correction, aided visual acuity should be measured.

B. Refraction:

Retinoscopy:

• Provides an objective measure of refractive error and provide a good approximation of the subjective refraction.
• Retinoscopy in a completely darkened room may be useful in the diagnosis of nocturnal myopia. 
• A careful subjective refraction should be conducted to determine the lowest minus lens power that achieves best visual acuity. 

Autorefractometer:

• Objective Autorefractometer may be substituted for retinoscopy, although an autorefractor will not give the qualitative information, like:
• Clarity of the ocular media, 
• Optical quality of the retinoscopic reflex, and 
• Fluctuations in pupil size 

Cycloplegic Refaction:

• Cycloplegic Refaction is required for the definitive diagnosis of pseudomyopia.

Keratometry

• Keratometry can be useful in predicting the degree of any astigmatism.

C. Ocular Motility, Binocular Vision, and Accommodation:

• Convergence excess, accommodative insufficiency, and accommodative infacility are frequently observed in patients with myopia.
• So testing should include assessment of:
•  accommodation, 
• vergence, and 
• binocularity. 

D. Ocular Health Assessment:

• Ocular Health Assessment of the patient with myopia should include:
• Direct or indirect ophthalmoscopy 
• Fundus biomicroscopy and 
• Measurement of intraocular pressure. 
• Slit lamp biomicroscopy 
• These testing is indicated risk of retinal and choroidal atrophy, and retinal breaks and detachment in patients with myopia.
• Viewing of the peripheral retina is enhanced by papillary dilation and is of particular importance in pathological myopia.
• Slit lamp biomicroscopy can be important in the differential diagnosis of:
• Induced or acquired myopia, 
• Contact lens-induced corneal edema, 
• Lenticular nuclear sclerosis. 

E. Supplemental Testing:

• May be indicated for identifying associated conditions and documenting and monitoring retinal changes in patients with degenerative myopia.
• These Supplemental Testing may include:
•  Fundus photography, 
• A- Scan and B-scan ultrasonography, 
• Visual fields, 
• Fasting blood sugar

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