Unit 7: Gradual Loss of Vision

Aetiology

Congenital cataract

Rare
May be detected as a loss of red reflex in newborn infants or as reduced visual acuity at school vision check
A third are inherited (autosomal dominant)
A third are caused by birth trauma, maternal infection during pregnancy (rubella and toxoplasmosis)

Age-related cataract

The most common type
Normal age-related degenerative lens changes lead to loss of transparency
Age is the main risk factor, but UV light and smoking increase the risk

Early onset (‘pre-senile’) cataract

Systemic disorders, e.g. diabetes
Trauma

Trauma

This is a traumatic rosette cataract seen in retro illumination (against the fundal red reflex) on the slit lamp. The leaf like "rosette" pattern is pathognomonic of a traumatic cataract and the clear zone outside the affected lens lamellae indicate that the trauma occurred several years before as clear lens fibres have been laid down in the periphery subsequently.

Source: eyerounds.org. Contributor: Dr. Swaranjit Singh Bhatti, Bhatti Eye Clinic.
Corticosteroids, e.g. tablets or eye drops
Ocular disorders, e.g. uveitis

Uveitis

White cataract secondary to anterior uveitis (intraocular inflammation). Despite dilating eye drops the pupil is not fully dilated. This is because uveitis can cause adhesions between the iris and lens (posterior synechiae), hence the pupil is ‘stuck down’, and immobile.

Source: eyerounds.org. Contributor: William Charles Caccamise, Sr, MD, Retired Clinical Assistant Professor of Ophthalmology, University of Rochester School of Medicine and Dentistry.

A hypermature age-related cortico-nuclear cataract with a brunescent (brown) nucleus.

Eye with cataract

Source: Cataract, National Eye Institute, National Institutes of Health, used under CC BY 2.0