Astigmatism – Types, Causes, and Management

🔹 Description:
This presentation provides a clear and simplified explanation of Astigmatism, one of the most common refractive errors of the eye. It covers the definition, differences between regular and irregular astigmatism, their causes, clinical features, and methods of diagnosis, including retinoscopy, keratometry, and corneal topography.
It also summarizes treatment options such as spectacles, contact lenses (RGP, toric, scleral, and hybrid), and surgical correction.
The slides include cases from the Eye Hospital and materials based on Dr. Moaz Shilfait’s cornea notes.

🎯 Best for:
Optometry students, ophthalmology residents, and anyone interested in understanding refractive errors in a simple, visual, and educational way.

1. Astigmatism
Refrective Error

2. Defintion of Astigmatism
•defect in an optical system causing light rays
•from a point source to fail to meet in a focal point
resulting in a blurred andimperfect image.
تكا يف عزوتي ةيكبشلا يلع ةدحو ةطقن يف شزكرتيام ءوضلا نا ينعي ر
ةشوشم ةروص يلخيب ءيشلا اده ةطقن نم
تافاسملا لك يف ةببضم وا

3. Type of Astigmatism
Regular Astigmatsim
•With-the-rule astigmatism
•— Against-the-rule
astigmatism
•— Oblique astigmatism
•— Bi-oblique astigmatism
Irregular Astigmatism
•Irregular change of
•refractive power in different
meredia.

4. Regular
astigmatism
Simple astigmatism
Compound astigmatism
Mixed astigmatism

7. Regular Astigmatism :
— Correctable by Spherocylindrical lenses
Etiology:
1. Corneal - abnormalities of curvature [common].
2. Lenticular is rare. It may be:

i. Curvatural - abnormalities of curvature of
lens as seen in lenticonus.
ii. Positional - tilting or oblique placement of
lens , subluxation.
3. Retinal - oblique placement of macula [rare].

8. Investigations:
❑— Retinoscopy
❑Keratometry
❑Computerized corneal Tomography
❑ Astigmatic fan test
❑Jackson cross cylinder
Treatment:
1.— Optical treatment
2.— Spectacles
3.— RGP contact lenses
4.— Toric contact lenses
5.— Surgical correction

9. Irregular Astigmatism:
Etiology:
•Corneal -[ Scars , Keratoconus, flap complications,
marginal degenration ].
•Lenticular -[Cataract maturation].
•Retinal-[scarring of macula,tumours of retina,choroid].

10. Treatment :
❖— Optical treatment :
➢- RGP contact lenses
➢-Hybrid contact lenses
➢-Scleral lenses
➢- Piggyback lens
➢— Surgical treatment:
➢- penetrating keratoplasty

11. نويعلا ىفشتسم نم تلااح

14. تاديلاس تيش نم
روتكدل ةينرقلا
زعم نويعلاطيفلش