الفهرس 
Materials and methodsOnly 14 pages are availabe for public view
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Abstract
The macula is about 5.5 mm in diameter. It is located
temporal to the optic disc. The central part of the macula (the fovea)
is 1.5 mm in diameter.
The fovea is surrounded by the parafoveal region which is
0.5mm in width the peripheal zone of the macular region (the
perifovea) is 1.5 mm in width.
Macular edema is defined as any retinal thickening with or
without partial loss of transparency within at least one disc area of
the centre of the macula.
The macular edema is either focal edema with focal areas of
leakage as microanurysms, or diffuse with diffuse leaking areas.
The main pathological factors contributing to macular edema
are loss of integrity of blood retinal barrier, I.R.M.A, tissue
hyperglycaemia which causes osmotic disruption and other factors.
The prevalence of macular edema increase with overall
severity of diabetic retinopathy, duration of diabetes mellitus and
higher glycosy1ated haemoglobin level.
The most important diagnostic examinations and
investigations are: fundus biomicroscopy, fundus photography and
fluoresceine angigraphy.
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The selected cases were treated with focal laser
photocoagulation for focal macular edema and modified grid for
diffuse cases of macular edema using argon green laser.
The prognosis was better in cases with early focal macular
edema than in cases with diffuse macular edema. Also, cases with
initial visual acuity better than 6/18 gave better results than those
cases with lesser visual acuity.
Field changes in the form of central and paracentral scotomas
are important complications in treated cases.
These field changes are less in cases treated with focal laser
photocoagulation than in cases of diffuse macular edema treated
with modified grid photocoagulation.
So in our study we found that:
Argon green laser treatment m the form of focal laser
photocoagulation in cases offocal macular edema, grid or modified
grid laser photocoagulation in cases of diffuse macular edema are
best waysof treatment in cases of .clinicaly significant macular
edema.
We found also that incidence and severity of macular edema
are related to many factors as:
Age of patients; younger patient gives better results on
treatment.
Duration of diabetes, the longer the duration of diabetes the
more is the incidence of macular edema and the worse is the results
of treatment.
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Type of diabetes; whether insulin dependent or-non-insulin
dependent, the incidence of macular edema increased in cases of
insulin dependent diabetics and the results were better in cases ofnon-
insulin dependent diabetices.
Also we found that visual results of treatment in the form of
visual improvement, stabilization or deterioration are better in
cases offocal than diffuse macular edema.
Also the patients of visual acuity > 6/18 gave better results
than patients with visual acuity < 6/18.
The field changes in the form of central and paracentral
scotomas is a significant complication in cases of macular edema
treated with argon laser. This complication decreased in cases of
mild focal macular edema treated with focal laser photocoagultion.
Field changes are well manifest in sever cases of diffuse macular
edema which are treated agressively with grid or modified grid
laser photocaoagulation.