myopic shifts

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myopic shift


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Myopic Shifts : 

Myopic Shifts

Normal dipotric shifts : 

Normal dipotric shifts Most healthy individuals go through several dioptric shifts throughout there lifetime Birth to age 1-2 Babies are born hyperopic and go through a myopic shift in the process called emmotrpization 7-16 years old A myopic shift occurs called school myopia Atributed to the increased time spent accomodated from reading and doing school work 17-25 years A second myopic shift same as above but called college myopia because most people are in college for this one 40-60 years old Error drifts towards hyperopia 60+ Error changes towards myopia Could be due to an increase in the index of the lens

Diabetes : 

Diabetes Will cause a fluctuations in dioptric error Lens swelling This is most commonly attributed to hyperglycemia causing the lens to swell increasing (-) error However, the mechanism behind this is poorly understood and several studies have actually suggested just the opposite that hyperglycemia causes a hyperopic shift Either way diabetes does cause a shift in dioptric power most likely due to swelling of the lens and then the lens returning to normal Insulin levels In an animal model it showed that insulin was a a powerful inducer of axial myopia There is not much information on this

disease : 

disease nephropathia epidemica (NE) Zoonose caused by the Puumala virus belongs to the group of haemorrhagic fevers with renal syndrome In the acute phase of the disease it causes forward movement of the anterior diaphragm and thickening of the crystalline lens resulting in a myopic One proposed mechanism is that the puumala virus multiplies in cappilary endothilial cells which causes increased leakage from these cells which releases osmolar molecules changes in the osmolarity of the aqueous and lens could cause these refractive changes

drugs : 

drugs Several drugs are known to cause myopic shifts Sulfonamides Topiramate is a sulfa derivative Acetazolomide This reaction is idiosyncratic, the mechanism behind it is still contreversial

How is this related to our case? : 

How is this related to our case? The lady in our case was taking the drug TOPOMAX which is just another name for topiramate Topiramate is often prescribed for epilepsy, MIGRAINES, depression, eating disorders, ,bipolar disorders, and trigeminal neuralgia Side effects of Topiramate are ACUTE ANGLE CLOSURE GLAUCOMA, ACUTE MYOPIA (MYOPIC SHIFT), suprachoroidal effusions, pre-orbital oedema, scleritis, blephorospasm, oculogyric crisis, nystagmus, and diplopia

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