Ans. a (Rhegmatogenous). (Ref Ophthalmology by Basak 4th/ 316; Kanski's 6th/349; Parson's 20th/311).The term rhegmatogenous is derived from the Greek word rhegma, which means a discontinuity or a break. A rhegmatogenous retinal detachment (RRD) occurs when a tear in the retina leads to fluid accumulation with a separation of the neurosensory retina from the underlying RPE; this is the most common type of retinal detachment.Types of Retinal detachments TypeDefinitionCauses1.RhegmatogenousFull thickness defect or hole in the retina with subretinal Fluid accumulation# Trauma (blunt)# Spontaneous# Myopia (high)# ICCE# Aphakia/Pseudophakia# Age-related retinoschisis# Vitreoretinal tufts and Meridional folds# Family history of RD2.Traction detachmentCaused by scar tissue pulling on the retina# Proliferative diabetic retinopathy# ROP# Sickle cell retinopathy ["sea-fan" retina)# Penetrating posterior segment trauma3.Exudative (serous) detachmentAs a result of inflammatory diseases or sometimes hypertension# Choroidal tumor# Exophytic retinoblastoma# Vogt-Koyanagi-Harada syndrome# Posterior scleritis# Infectious (syphilis, TB, CMV, Toxoplasmosis)# Subretinal vascularisation# Collagen vascular diseases# Coats disease# Central serous chorioretinopathy# Uveal effusion syndrome# Renal diseases# Severe hypertension/ eclampsia/ preeclampsiaRx of Rhegmatous RD (essentially surgical & immediate)A. Sealing the retinal breaks (cryoretinopexy/diathermy/Laser)B. Scleral bucklingC. Subretinal fluid drainageD. ntravitreal injections (air or Ringer's solution)E. Vitrectomy