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Presentation on theme: " The Retina  Contains photoreceptor cells (rods and cones) and associated interneurones and sensory neurones."— Presentation transcript:



3 The Retina

4  Contains photoreceptor cells (rods and cones) and associated interneurones and sensory neurones.

5  This is the process by which light initiates a nerve impulse.  The structure of a rod cell: Detection of light is carried out on the membrane disks These disks contain thousands of molecules of rhodopsin (photoreceptor molecule)

6  Refractive errors like nearsightedness and farsightedness, astigmatism, presbyopia  Allergies to dust, pollution gases, pollen etc.  Infection of eye lids like stye, chalazion  Squint  Cataract  Glaucoma  Tumors  Age related macular degeneration  Diabetic and hypertensive retinopathy  Optic nerve related disease

7  Headache  Blurring of near or distance vision  Watering from eyes, swelling  Itching, redness, irritation.  Twitching, fatigue  Eye pain or pain deep in the socket  Floaters (dots or web)  Double vision, problem in night vision. www.

8  Myopia- Rays from the distant object comes to a focus in front of retina.  Hypermetropia -Rays from the object comes to a focus behind the retina.  Astigmatism -It is the refractive error in which the focusing of rays from far object is not the same in the different meridians of the refracting system of the eye.  Presbyopia- Physiological condition when the accommodative power of the normal lens become less.

9 Refractive error can be corrected by  Spectacles  Contact lenses  LASIK

10  These are caused due to dust, increasing pollution, toxic gases.  These allergies might be seasonal e.g summer (dust) or spring season (pollen grains).  Symptoms- redness, itching, watering, swelling of eyelids or lid margins.  Treatment is antiallergic eye drops and steroid eye drops.  Prevention of allergens. www.

11  Stye is infection of hair follicle on eyelids. This causes swelling and pain on lid margins  Chalazion is pea like swelling on the lids, this is due to chronic inflammation of mebomian glands of the eyelids.  Blephritis is chronic inflammation of eyelid margins leading to dryness and flaking. This gives rise to itching of eyes, lid margins and corner of eyes. Redness and dryness of eyes causes discomfort.

12 Conjunctivitis - Bacterial, viral and allergic. Keratitis - Infection of cornea. Sometimes leads to ulcer formation. Uveitis- inflammation and infection of inner layers of eye, which is associated with other systemic disease like arthritis and tuberculosis etc. this if not diagnose in time can lead to permanent decrease of vision. Symptoms are redness of eyes and reduction in vision. Discomfort in bright light and eye pain.

13  Depends on the cause allergic or infection  Inflammation is treated by supportive treatment and tear substitute. Causative systemic disease has to be diagnosed and treated.  Infection is treated by oral and local antibiotics and antiviral. Painkillers and antacids are supportive modalities

14 Squint:  Misalignment of visual axis or when both eyes are not looking in the same direction.  Paralytic or concomitant:  Muscle paralysis or neurological reason.  Treatment is evaluation, spectacles and surgery.

15  Opacity in the natural crystalline lens is called cataract.  Old age disease but can occur in newborn babies and adults due to infection in intrauterine period or malnutrition. Certain metabolic disease also cause cataract in young.  Treatment is surgery phacoemulsification with artificial lens implantation.

16  This is defined as raised intraocular pressure  Changes in the perimetery or visual field  Change in optic nerve.  Vision lost due to this is irreversible so quick diagnosis and treatment is an answer  Usually occurs in above 40 age group, family history, hypermetropia  Hypertension is a risk factor.  Check your eye pressure on every visit to an eye doctor ( if you are above 40 yrs )  Treatment : eye drops,laser iridotomy,surgery.


18  Retinopathy and cataract are commonest eye problem in diabetics.  Early diagnosis is required because there could be irreversible damage to eye site.  Retinopathy may lead to retinal detachment and glaucoma which can permanently damage eyesight.  If detected early patients can be managed medically by OCT, FFA and laser treatment


20  Optic neuritis  Optic nerve edema or papilloedema.  Optic nerve atrophy. OTHER EYE DISEASE LIKE Age related macular degeneration. Various benign and malignant tumors www.

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