What is a cataract, what causes it,
symptoms and treatment
What is cataract?
Cataract is the clouding of the crystalline lens of the eye.
What causes cataracts?
Normally, the lens of the eye is clear. Over the years, the lens hardens and blurs. This type of cataract is called “age-related cataract” and is the most common. However, there are other types of cataracts, such as congenital, traumatic, steroid-induced and inflammatory. There is a correlation between cataracts and specific diseases, such as diabetes mellitus, myotonic dystrophy, severe atopic dermatitis. Smoking and ultraviolet (UV) radiation have been implicated in increasing the risk of developing cataracts.
What are the symptoms of cataracts?
Cataract causesblurred vision, which usually occurs gradually. In some people and with certain types of cataracts, vision may deteriorate more abruptly. Cataracts can also cause difficulty driving at night, dysphotopsia and monocular diplopia. The ability to read up close without the need for presbyopia glasses is often a sign of cataracts.
What is the treatment of cataracts?
Cataracts can only be treated surgically. It involves the removal of the cataractous lens (most commonly by phacoemulsification) and the implantation of an”artificial” lens, called anintraocular lens.
When does cataract need treatment?
Early-stage cataracts cause minimal visual symptoms. For this reason, measures such as the prescriptionof new glasses may work satisfactorily for some time.
Cataract surgery is performed when:
- causes severe visual disturbance that cannot be corrected with glasses/contact lenses
- causes secondary problems, such as an increase in intraocular pressure (phacogenic glaucoma)
- interferes with the examination of the fundus of the eye and subsequent treatment (e.g. laser application in cases of retinal vascular disorders)
In any case, your physician will discuss the benefits of cataract surgery with you, taking into account your habits and preferences.
Is there any chance that the cataract will return to my operated eye?
No. In some patients who undergo cataract surgery, a blurring occurs in the thin membrane behind the intraocular lens. This membrane is called the “posterior capsule”. This is a condition called “posterior capsule opacification” or “secondary cataract” that causes adecrease in visual acuity. Posterior capsule opacification occurs in 20-50% within 2-5 years of cataract surgery and is significantly more common at younger ages. The treatment is performed with Nd:Yag laser in the ophthalmology clinic.
How is cataract diagnosed? What does preoperative screening include?
After taking your medical history, your surgeon will perform a series of tests to determine whether you have a cataract and whether it can be removed. They will also assess the structure and anatomy of your eyes to determine which intraocular lens is right for you, adjust the surgical technique and tell you what to expect from surgery.
In our clinic the preoperative screening includes:
- Measurement of visual acuity and refraction
- Measurement of intraocular pressure
- Ocular motility test
- Slit lampexamination to assess the condition of the lens and the anterior segment in general
- Fundoscopyto check the optic disc, macula, peripheral retinal lesions, etc.
As far as imaging tests are concerned, our clinic performs the following:
- Optical biometrics and corneal tomographyusing thePENTACAM AXL® OCULUS ®, for the most accurate assessment of the characteristics of the intraocular lens to be selected.
- A-scan ultrasound biometry, to estimate the axial length of the eye.
- Β-scan Ultrasonography, for the assessment of the fundus of the eye in cases of dense cataracts, where fundoscopy becomes particularly difficult.
- Anterior chamber OCT, for assessment of the structures of the anterior segment, such as measurement of the angle of the anterior chamber, estimation of corneal thickness, etc.
- Ultrasound biomicroscopy (UBM), a specialized examination, which allows to assess the structures of the anterior segment in front and behind the iris.
- Endotheliometry, i.e. recording of the number and mainly the morphology and size of corneal endothelial cells. The endothelial cells act as a pump to keep the cornea clear. Age, certain dystrophies and surgical manipulation can lead to changes in endothelial cells, that can affect the outcome of surgery. Endotheliometry therefore contributes to providing the patient with the most complete information possible and to selectingthe most appropriate surgical technique.
OCT and OCT angiography to assess optic disc and macular disease, which can affect the outcome of surgery. They need to be diagnosed as they often need to be treated before cataract surgery.