BY SUNNDEEP CHOPRA
DETACHED RETINA: Is nothing more or less than the complete separation or then segregation of the proper neuro sensory retina from the pigment epithelium (the pigmented cell layer located just attached the retina which is attached to the choroid). These two layers are known to be loosely attached to each other with an underlying or then open space between the two. In actual terms, the nomenclature retinal detachment is a misnomer or red herring and the actual term employed should be retinal separation.
DETACHED RETINA FEATURES OR SYMPTOMS:
1. Prodormal Symptoms: These always include the formation of dark spots (floaters) in front of or then in a straight line with the eye and the same is caused by either rapid vitreous degeneration and photopsia i.e. sensation of experiencing intermittent flashes of light in front of the eye on account of the retina being irritated or bothered by sudden and abrupt vitreous movements.
2. Localised or then area specific relative loss in the field of vision (of detached retina) is noticed or spotted by the patient in the very early stages or stages of infancy gradually leading to a complete or total loss when peripheral detachment gradually progresses towards the macular area and begins to assert itself.
3. Sudden or abrupt painless loss of vision occurs when the resulting detachment or dissociation is both large and central. Such patients always complain about the appearance of a dark cloud or then veil or shroud in front of or then in direct line with their eyes.
SIGNS OR MANIFESTATIONS: These are normally elicited after subjecting the affected eye to the following examinations:
A. External Examination/s: the eye is always found to be normal
B. Intraocular pressure may either be just below normal or normal and could vary marginally from patient to patient.
C. Marcus Gunn Pupil (relative afferent papillary defect) is normally found or spotted in eyes with (cases of) extensive or wide reaching retinal detachment.
D. Resorting to a plane mirror examination reveals or then throws light on an altered or changed reflex within the papillary area (i.e. grayish reflex in the quadrant of the detached retina).
E. Opthalmoscopy (is a clinical examination of the nether (back) regions of the eye (fundus) that includes the retina and optic nerve) should be initiated by taking recourse to both direct and indirect methods or techniques and is best examined or established by resorting to indirect opthalmoscopy inclusive of sclera indentation (to enhance or then increase the visualistion of the peripheral retina anterior to the equator). A freshly or then recently detached retina exhibits a grey reflex instead of it’s characteristic pink reflex under clinical examination. Old or then ancient detachment is characterized or identified by retinal thinning on account of atrophy, the formation of a subretinal demarcation line (high water marks) due to the proliferation of RPE cells at the junction or point of intersection of flat detachment and the formation of secondary intra retinal cysts in pre historic cases of retinal detachment.
4. Visual field charting area: exhibits or reveals scotomas (an area of partial alteration in one’s field of vision) corresponding or then native to the area of detached retina which are relative at the beginning but exhibit a tendency towards becoming absolute in long standing cases of the same.
5. Electroretinography (measures the light related responses of various cell types in the retina including the photos and rods) is either subnormal or then totally absent.
6. Ultrasonography: confirms or endorses the original diagnosis and is of immense or then particular value in cases of patients with hazy or unclear media especially in the presence of dense cataracts.
COMPLICATIONS: These normally or usually occur in prolonged and long standing cases and almost always include proliferative vitreoretinopathy (PVR) (expanding or increasing vitreal and retinal damage) and complicated cataracts.
Exudative (oozing of fluids and other materials from cells and tissues on account of inflammation or injury) retinal detachment can be differentiated from a simple primary detachment on account of the factors mentioned below:
Ø Complete or conspicuous absence of photopsia, holes/tears, folds and undulations.
Ø The exudative detachment is normally smooth and convex. It is usually rounded, fixed and may show pigmentary disruptions or disturbances at the summit or pinnacle of a tumour.
Ø The normal pattern of retinal vessels may show signs of disturbance or disruptions from normal on account of the presence of neovascularisation on the tumour summit.
Ø Exudative retinal detachment is almost synonymous with the presence of shifting fluid or then changing/shifting position of the detached area in direct co-relation to existing gravitational forces.
Ø A simple detachment al ways appears to be transparent and a solid detachment opaque when subjected to a trans illumination test.
DETACHED RETINA SURGERY:
Tractional Retinal Detachment occurs due to the mechanical separation or pulling away of the retina from its laid down bed due to the contraction of fibrous tissue in the vitreous (vitreoretinal tractional bands).
- Exudative retinal detachment due to transudate (extravascular fluid with low protein content and a low specific gravity), exudate (any fluid that filters from the circulatory system into areas of lesions or inflammation) and haemorrhage may undergo spontaneous regression upon absorption of the fluid. The treatment if any should always be focused upon the requisite and necessary treatment of the causative disease.
- Presence or manifestation of intraocular tumours always requires enucleation (surgical removal of the entire eye).
The treatment of cases of tractional retinal detachment is complicated and time consuming; and always requires or includes pars plana vitrectomy (a surgical procedure that involves or entails the removal of retinal fluid from the eye) in order to dissect the vitreoretinal tractional bands and internal tamponade (structures within the human eye). The resulting prognosis in a significant majority of such cases is far from encouraging.
CAUSES FOR DETACHED RETINA: The most significant or predisposing factors for the same are:
1. This disease is most commonly found or rampant in people between 40-60 years of age. Though, age is no bar for the onset or incidence of the same.
2. Sex: more common or widespread in males. The rate of incidence in males versus females is normally 3:2.
3. Myopia or then ‘shortsightedness’: around 40% of all cases of rhegmatogenous retinal detachment are myopic in nature.
4. Aphakia: is a condition where the natural crystalline lens has been extricated from the eye and hence the condition is far more common in aphakes in comparison to phakes.
5. Retinal Degenerations predisposed or then favourably inclined or disposed towards retinal detachment are as under:
Ø Lattice degeneration
Ø Snail track degeneration
Ø White with pressure or white without or occult pressure
Ø Acquired retinoschisis
Ø Focal pigment clumps
6. Trauma can also be a predisposing or hugely contributory factor.
7. Senile posterior vitreous detachment which is commonly found in many a case of retinal detachment.
ADDITIONAL CAUSES: Are as under:
Ø Post traumatic retraction of scar tissue especially after penetrating surgery.
Ø Proliferative diabetic retinopathy
Ø Post haemorrhagic retinitis peoliferans
Ø Retinopathy of prematurity
Ø Plastic cyclitis
Ø Sickle cell retinopathy
Ø Proliferative retinopathy in cases of Eales’ disease (is an ocular disease characterized by the possible blockage of retinal eye vessels and their inflammation).
TYPES OR CLASSIFICATION: Clinico-etiologically retinal detachment can be or is classified or sub-divided into three categories or types:
A. Rhegmatogenous or then primary retinal detachment.
B. Tractional or secondary retinal detachment and
C. Exudative or a more advanced cases of secondary retinal detachment.
PREVENTION: The occurrence or then incidences of primary retinal detachment can be inhibited or prevented by the timely intervention or application of laser photocoagulation (is an out patient retinal treatment where tears or lesions of the retina are cauterized through/by the heat generated from pin-pointed laser rays) or cryotherapy (is a technique used to reduce the associated post-operative pain or swelling through the usage of ice and other cold therapies) in the areas of retinal breaks/ affected areas and/or predisposing lesions like lattice degeneration. The initiation or then resorting to of prophylactic measures is highly desirable or indicated in patients with associated or then inter linked high risk factors such as: myopia, aphakia, retinal detachment in the affected or fellow eye and history of retinal detachment within the family.
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