Myopia - Clinical picture 3/4

Symptoms of Myopia:

1. Simple myopia:

i. Blurred distance vision

ii. Asthenopic symptoms: due to-

• Astigmatism,
• Anisometropia,
• Accommodative dysfunction, or
• Vergence disorder.

iii. Half shutting of eye

2. Nocturnal myopia:

i. Blurred distance vision

•  only in dim illumination or in dark conditions

ii. Difficulty in driving at night

3. Pseudomyopia:

i. Blurred distance vision: 

• may be constant or intermittent but significantly increase after near work

4. Degenerative or pathological myopia:

i. Blurred distance vision: blur is constant.

ii. Vitreous floaters: 

• due to degenerated liquefied vitreous

ii. Night blindness: 

• if rods and cones are damaged

5. Induced myopia:

i. Blurred distance vision: 

• lasting a few hours depending upon the particular agent or condition causing it.

Signs of myopia:

1. Simple myopia:

a. Reduced unaided distance visual acuity

b. Large and prominent eyeballs

c. Deep anterior chamber

d. Sluggishly reacting pupil

e. Fundus: 

• usually normal and rarely myopic crescent may be seen

f. Magnitude of refractive error:  

• occur between 5 and 10 year of age and it keeps on increasing till about 18-20 years of age at a rate of about –0.5 ± 0.30 every year.

2. Nocturnal myopia:

i. Retinoscopy: 

• Retinoscopy in a dark room may be shifted in the minus direction

3. Pseudomyopia:

i. Fluctuations in accommodation: 

• observable as variations in visual acuity and Retinoscopic reflex

ii. Cycloplegic refraction: 

• more minus power on the manifest refraction than on the cycloplegic refraction

4. Degenerative or pathological myopia:

a. Prominent eye balls

b. Cornea is large

c. Anterior chamber is deep

d. Large and sluggish pupils

e. Visual field contraction

f. Electroretinogram (ERG) :

• may be subnormal due to chorioretinal atrophy

g. Fendus sign:

• Large and pale optic disc
• Tilted optic nerve with peripapillaryatrophy
• Temporal myopic crescent
• Chorioretinal atrophy
• Peripheral vitreous detachment
• Lacquer cracks
• Lattice degeneration
• Cobblestone degeneration
• Foster-fuch’s spots
• Peripheral retinal holes
• Macular holes
• Choroid neovascularisation(cnvm)

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