November 21, 2020

Ocular Diseases

This page aims to provide information in simple language about various eye diseases. Knowing about diseases and how to prevent them is important for your health. In case of illness, this information should never replace medical consultation.


Refractive Defects (myopia, hyperopia, astigmatism, presbyopia, diabetic retinopathy).

The most frequent visual problems are refractive defects. These refer to a set of alterations in which there is an inadequate focusing of the images on the retina. Most of them are easily corrected with glasses or contact lenses. In rare cases surgery may be an option.


It is important to know that:

many visual changes are not refractive defects (several ocular and non-ocular diseases lead to visual disturbances); some refractive defects may be caused by certain diseases that only an eye doctor can assess properly;


Myopia - Is a situation in which the image is focused in front of the retina and is translated by a difficulty in seeing far away. A myopic eye is usually larger than normal and is more prone to some diseases (eg glaucoma, retinal detachment, etc.) so it needs special attention from the eye doctor.


Hyperopia is a refractive defect characterized by difficulty in seeing near objects. It usually causes eye fatigue and even headaches when working more closely or when reading, due to the increased focus required of the eyes. A hypermetric eye is usually smaller than normal and the "resistance" to hyperopia decreases with age. It can be the cause of a child's poor performance at school


Astigmatism - corresponds to an unequal visual quality depending on the visual axis in question. In most cases it is due to an unequal curvature of the cornea causing distorted vision. It can occur in isolation or associated with the other refractive defects.


Presbyopia (or tired eyes) is the difficulty in seeing near objects that is normally experienced from a certain age (around 45 years of age). It is due to the progressive loss of elasticity of the lens as a result of age.



What is a cataract? Any change in the transparency of the lens (see under Normal Eye ) is called a cataract.

What are the causes of cataracts? They are most often the result of normal aging but can also be congenital or due to a variety of other factors such as: trauma, chronic eye diseases or systemic (whole body) diseases such as diabetes.

What are the symptoms of cataract? Cataracts usually result in a blurred image but several other complaints may result from their presence. Diagnosis should always be made by observation by an ophthalmologist.

How are cataracts treated? The main treatment for cataracts is surgical. Cataract surgery consists of removing the opacified lens and inserting an "artificial lens" inside the eyeball (intraocular lens) leading to visual recovery. There are several ways to perform cataract surgery but the most current and evolved is called phacoemulsification.



What is glaucoma? It is a disease of the eyes in which there is a progressive increase in eye pressure leading to a decrease in vision (which can even lead to blindness). There are several types of glaucoma but the most common (and the one to which this text is dedicated) is open angle glaucoma.

Why does eye pressure rise? There is a transparent liquid that circulates from the inside to the outside of the eyeball (aqueous humour). In people with glaucoma, and for reasons that are still not well known, this fluid starts to have difficulty exiting the eyeball, leading to an increase in eye pressure.

What are the symptoms and dangers of glaucoma? Increased eye pressure, if not detected and properly treated, leads to the slow and progressive "death" of the nerve responsible for vision (optic nerve). These changes cause a loss of vision (especially of our field of vision). Glaucoma only shows symptoms at an advanced stage of the disease and the changes in vision are only felt by the patient when the optic nerve already has severe and irreversible damage.



The term strabismus is used whenever there is a misalignment of the eyes. This eye problem usually occurs in children and in many children it can be present from birth. It is very important to diagnose and treat this condition when the child is still small, otherwise the vision in one eye can be irreparably impaired. The child with strabismus tends to use the deviated eye less and it becomes 'lazy'. This visual impairment resulting from strabismus is called amblyopia.

Strabismus can be constant or arise only at certain times. The eyes may be deviated inwards, outwards, upwards or downwards. These deviations may also be associated.

Persistent eye deviation in a 4-month-old child makes an eye examination necessary. It is also recommended that all children have an eye examination by 6 months of age.

Strabismus can also arise in adults due to illness or trauma.


Diabetic Retinopathy

Diabetes is a disease in which, among other changes, there is an increase of "sugar" in the blood. This lack of control can damage various areas of the body. The eyes are one of the organs that can be seriously affected although initially there are no major symptoms. The diabetic retinopathy is an ocular manifestation of the disease and is one of the main causes of blindness. To avoid blindness it is necessary to control blood sugar levels (glycaemia) as well as possible from the early stages of the disease.

Diabetic retinopathy results from changes in the small retinal blood vessels inside the eye. The altered vessels leak fluid and blood into the retina leading to decreased vision. In some cases abnormal vessels develop in the retina. These vessels are very fragile and bleed easily, leading to the formation of fibrous tissue that pulls on the retina. This stage of the disease is very serious and is called proliferative diabetic retinopathy.

A diabetic should regularly have a medical eye examination to detect the early changes of diabetic retinopathy. Sometimes treatment with laser beams is necessary. Remember, however, that better than treating the changes is to try to prevent them by taking better care of your health and, if you are diabetic, by adopting a lifestyle that allows you to control the disease