Applied anatomy
The macula is an oval area about 5 mm in diameter located at the posterior pole.
Within the macula, points of clinical importance are the fovea, foveola, and foveal avascular zone. Fovea diameter is approximately 1.5 mm.
Evaluation of macular disease symptoms
The main symptom of macular disease is weakening of central vision.
Typically, the patient complains of the presence of something obstructing central vision (positive scotoma).
In optic nerve pathologies, there is a negative scotoma, which is usually not noticed by the patient, but revealed in the visual field test.
Other symptoms of macular disease that are not seen in optic nerve disorders:
a. Metamorphopsia, which means a change in the shape of an image
b. micropsia, meaning reduction of image sizes
c. It is macropsia, which is the increase in image dimensions.
Color vision is impaired in optic nerve lesions.
In macular (retina) diseases, color vision is not affected in the early period.
Age-Related Macular Degeneration (AMD)
I. Prevalence:
The most common cause of irreversible blindness over the age of 70 in the Western world: Age-related macular degeneration.
2. The two main types of AMD are shown below:
a) Dry type (non-exudative)
It is a slowly progressive atrophic clinical condition that is responsible for 90% of cases.
b) Wet type (exudative)
It is devastating, although much less.
The patient soon becomes blind.
3. Drusen - often found with subsequent development of AMD - are yellow-white spots in the posterior pole.
4. The screening test used in age-related macular degeneration is the Amsler-grid test.
Histopathology
Dry type (Atrophic) AMD
Atrophic (dry, non-exudative) AMD currently constitutes the most common type, responsible for approximately 90% of cases.
Although the provision of low-vision aids in treatment is beneficial in many patients, there is no definitive cure for this disease.
Wet type (Exudative) AMD
The disease presents with sudden onset of metamorphopsia and blurring of central vision.
There is a dirty gray or yellowish-gray discoloration in the subretinal region.
Argon laser photocoagulation, photodynamic therapy, experimental treatments (macular surgery, intravitreal gas injection, transpupillary thermotherapy) and anti-VEGF agents (Ranibizumab, Aflibercept and Bevacizumab) are used in treatment.
Uses of Anti-VEGFs in Ophthalmology:
diabetic macular edema
Proliferative diabetic retinopathy
retinal vein occlusion
wet type AMD
retinopathy of prematurity
Pre-surgical window treatment in neovascular glaucoma
