Ocular Diseases

Just like any other organ, the eye is susceptible to diseases.  Luckily, in most cases, it is possible to identify them quickly by having regular eye exams where the optometrist will screen for warning signs.

Here is a list of the main eye diseases for further research.

Cataract

A cataract is the clouding of the eye lens causing gradual decrease of vision, blurry vision, and extreme light sensitivity.  At 65, one person out of five is affected whereas at 75, the ratio increases to one person out of three and one person out of two at 85. Although this disease strikes around 60 years of age, it can manifest itself around 50 and even 40 years of age.

The only treatment for a cataract is surgery where the natural eye lens is replaced by an artificial one.

Glaucoma

Glaucoma is an insidious disease because there are no warning signs. It can be caused by multiple factors:  age, heredity, severe myopia, past traumatic ocular incidents, hypertension.  These factors all affect the internal eye pressure and can lead to the destruction of the optical nerve.  After diabetes, glaucoma is the most frequent cause of blindness in developed countries.

There are two types of glaucoma:  

Open angle glaucoma is not painful and there are no particular symptoms.  Only an ophthalmologist can detect a burgeoning glaucoma and treat it in time.  There is no standard treatment as each case is different.  Collyrium drop solutions are most often prescribed.  In certain cases, surgery is necessary but it is a very benign operation.  

Angle-closure glaucoma, however, does not go unnoticed.  When the iridial angle, which is naturally very thin, is obstructed, the aqueous humour cannot circulate freely, causing a rapid increase of eye pressure.  The extreme pain develops in a few hours and vision is dramatically altered.  

Angle-closure glaucoma is an emergency that requires, first, medical intervention to lower the eye pressure and, second, surgical intervention to prevent the obstruction to occur again.

Conjunctivitis, Styes and Other Ocular Infections

Ocular infections are frequent and generally benign.  Luckily, there is medication to treat them.

Conjunctivitis is usually caused by a virus or a bacteria but it can also be the result of some allergy. It is the infection of the conjunctiva, a transparent membrane covering part of the ocular globe and the inner side of the lids.  

Conjunctivitis is identifiable by a redness of the eye, an itchy feeling, as well as thicker secretions that can hinder the eye opening in the morning.

Conjunctivitis is usually viral, without serious consequences, and will disappear after a few days.  Since a virus is contagious, the other eye may become infected as well.  It is therefore very important to wash hands often and not rub the infected eye has the virus could spread around.  
 

Stye is the result of an infection in the lash follicle.  It appears as a small and swollen red pimple. It is treated by applying an antibiotic ointment as well as hot humid compress that will aid the ripening of the stye.   Once the stye has burst, recovery usually follows on its own.

Chalazion is a usually pain free cyst caused by the obstruction of the Meibomius glands that produce the oil part of tears.  It can be treated with Collyrium or antibiotic and/or anti-inflammatory ointment.  However, surgery is often needed, under local anaesthesia, in which an incision is made underneath the eye lid.

Keratitis or cornea infection may be caused by a virus, a bacterium, or a fungus (often brought on by contact lens wear).  Erosions or ulcerations appear on the cornea, causing blurry vision.  The eye becomes red, painful and light sensitive.

It is best to consult an ophthalmologist in the case of a keratitis as antibacterial or antiviral products need to be prescribed to speed up healing otherwise some cornea opacification may occur, which may affect vision permanently.  The healing period is longer than for conjunctivitis.

Age-Related Macular Degeneration (ARMD)

Age-Related Macular Degeneration, or ARMD, affects the macula which is a small area located in the centre of the retina and responsible for visual acuity.  It translates into a scotoma, a partial obstruction of the visual field, by creating a black spot in the centre of the looked upon object.  Near vision, especially in the case of reading, rapidly becomes a serious problem.

Examination of the back of the eye allows detection of ARMD.  Unfortunately, although some medications and laser treatments may stop the progression of the lesions, as of now no treatment can restore the lost vision.  

One of the first signs of ARMD is the impression that straight lines curve or warp.  An examination by an ophthalmologist is then required.

Retinal Detachment

The retina is the membrane covering the back of the eye with sensory vision cells. It is attached to the ocular globe’s outward membranes.  The retina detaching from these membranes is a grave ocular affection that can lead to blindness.  Its treatment is surgical only.

Diabetics are particularly prone to lesions and/or detachment of the retina and need regular check ups.

Floating Spots (or Muscae Volitantes)

A wide spread phenomena, floating spots are small opacities of various shapes and densities that float about the vitreous humour (the eye) rather like wine dregs.  Depending on the angle, the shade projected by these spots hit the retina and appears over the looked upon object.  

The floating spots cannot be treated and are not dangerous as long as there are only a few.  Should the number increase and should there be streaks of light, an examination of the back of the eye must be done rapidly by an ophthalmologist as it may indicate intra-ocular bleeding, vitreous humour, or retina detachment.

Retinitis Pigmentosa

This is a hereditary disease usually affecting only a few family members.  It is most often diagnosed between 10 and 20 years of age.  Retinitis Pigmentosa causes a progressive decrease of vision.  As the vision slowly diminishes, it is more and more difficult to read.  In the end, the central visual field is totally obstructed by a scotoma. 

There is no treatment for Retinitis Pigmentosa.  However, visual aids such as lighted magnifying glasses and enhancing electronic systems can help maintain a functional vision for a relatively long period.