It is a group of inherited defects whereby patient suffers in distinguishing the primary colors. It is usually bilateral and the patients with these defects become ineligible for certain jobs that requires precise recognition of colors like heavy vehicle drivers, auto drivers, railway drivers etc.
It is the condition in which the cornea of the eye is usually infected. It can be viral, bacterial and fungal infections. It is one of the ocular emergencies which when left untreated may lead to permanent loss of vision. Mostly occurring in low socio economic group people with history of injury and also following treatment of trivial trauma with native medicines, which have to be avoided.
Otherwise called as Double vision usually occurs when there is paralysis of any of the ocular motor nerves leading to inability to move the eye in the desired decision. There may also be involvement of the central nervous system. Which would require radiological and surgical management in few cases.
Eye haemorrhage can involve both anterior and posterior segments. The commonest cause being trauma. The commonest type being sub-conjunctival haemorrhage. Bleeding can also occur into anterior chamber and vitreous leading to loss of vision. Vitreous haemorrhage is a common cause of painless loss of vision.
Diseases of retinal blood vessels like Eale’s disease in the young and systemic disease like diabetes mellitus & hypertension in the old are also causes of vitreous haemorrhage.
It literally means, “Shut eye”. Commonly known as “short sight”, since the myopic person can only see near objects clearly while distant objects will appear blurred. To some extent the blame could be placed on heredity. Can be corrected with spectacles, contact lenses and refractive surgeries (Once the refractive power stays constant).
As “hemiplegia” denotes inability to move one half of the body, “ophthalmoplegia” denotes inability to move the eye in a particular direction or a particular eye as a whole. It can be congenital or acquired. Congenital form can be associated with other neurological conditions; diplopia may not be a presenting complaint. In the acquired type double vision is the predominant complaint. Any affection of the CNS has to be ruled out in all these cases.
They are a group of conditions, which lead on to gross defective vision due to affection of the optic nerve. Can be sudden or gradual, usually gradual and progressive. May be congenital when it leads on to defective vision from birth and may be associated with other CNS anomalies. Can be acquired when it can be due to trauma, inflammation of optic nerve or due to increased IOP, which are the commonest cause. When detected early can be reversible, at least partially prevents total gross loss of vision.
It is inflammation of optic nerve when the patient comes with history of acute, sudden gross loss of vision. Maybe associated with painful movements of the eye. The optic nerve can be involved primarily in association with inflammation of adjacent structures like the sinuses, CNS, etc. Usually divided into retrobulbar neuritis, where neither the patient nor the doctor sees anything. Or optic neuritis where there will be signs of inflammation in the optic nerve head, which can be picked upon fundus examination. Usually reversible but recurrent. May be unilateral or bilateral (especially in children). May occur in lactating females commonly. If it is recurrent, showing remissions and relapses, a demyelinating disease affecting CNS has to be ruled out. In case of RB neuritis, the only clue may be RAPD, which have to be looked for in all cases with sudden loss of vision and treatment has to b e started immediately in the form of IV steroids even if there is a suspicion without waiting for confirmatory lab results.
RETINAL DETACHMENT (RD)
It is a misnomer in the sense that there is no “detachment” of the retina but only a separation of neurosensory layer of retina from retinal pigment epithelium. It leads to sudden painless loss of vision. Commonest eye condition associated are myopia, aphakia, proliferative vitreo retinopathies like diabetes mellitus, Eale’s etc. Can follow trauma especially in young individuals. When diagnosed early, visual recovery can be achieved by surgical approach. Periodic checkups and treatment if necessary, in patients with peripheral vitreous diseases, high myopia can prevent development of RD.
It is the condition in which blood vessels of the retina are involved in patients having long standing diabetes mellitus. As eye is the only region in the body where vessels can be visualized using ophthalmoscope, it throws light on the condition of other organs. A patient with DM for >5 yrs should have periodic checkup at least once a year. A patient with proliferative diabetic retinopathy (PDR) can undergo pan retinal photocoagulation (PRP) to prevent further advancement of the disease. There can be some decrease in visual field after PRP. Research and usage of Laser treatment has done wonders in sustaining useful vision in many of these patients.
RETINITIS PIGMENTOSA (RP)
It is a misnomer since there is no inflammation of the retina. It is usually inherited condition, in which the patient complains of defective vision in the night. It progresses slowly leading to defective vision associated with constriction of field of vision. Though most of the patients retain tubular field of vision for a long time, some patients may go for progressive consecutive optic atrophy. Though many modalities of treatment are being followed, there is no cure as of now. Since it is a inherited disease, research in genetics may throw light on this potentially vision threatening abiotrophic disease.