Farsightedness

Light is focused behind the retina

COrrected with a convex lens 

Nearsightedness

Light is focused in front of the retina into the vitreous chamber

Corrected with a concave lens 

Age related macular degeneration

(risk factors) 

Age

Race (caucasian, fair cplxn)

Family Hx

UV exposure

Tobacco use 

Degeneration of the central retinal epithelium

Leads to druchen (waste procucts) 

Accumulate along Bruch's membrane 

Geographic atrophy[image]

Any of the components of dry macular degeneration

PLUS abnormal blood vessel growth under the retina and RPE

Leakage of fluid from vessels "wet"

Scarring and destruction of the central retina

**More Severe** 

Dry macular degeneration

Druchen build up in Bruch's membrane 

Wet macular degeneration

Blood vessels develop under retina or RPE and bleed and scar recurrently 

Due to vascular damage occuring from high glucose levels in the blood

Thickened basement membrane

Endothelial dysfunction

Loss of pericytes 

Microaneurysms

Intraretinal hemorrhages

Exudates

Cotton-wool spots

Retina becomes ischemic and angiogenic factors are released

Stimulates neovascularization ON the retina

Abnormal vessels bleed and scar

Causes retinal retraction and eventual blindness 

Increased interocular pressure due to excess aqueous humor

Increased pressure causes axons of optic nerve to die back

Leads to "cupping" of the optic disk

Larger appearance and pallor 

Diabetic retinopathy

(Leading cause of permenant blindness in ages 20-60) 

(99% of type I diabetics, 60% of type II diabetics) 

Glaucoma

(10% of people worldwide, more in African-Americans and Hispanics) 

Age-related macular degeneration 

(Leading cause of blindness in caucasians over 50) 

Glaucoma optic cupping

Note large disk size and pallor (yellow color)