Baby born prematurely at 29 weeks on examination at 42 weeks with ROP both eyes shows stage 2 zone I "plus' disease, how will you manage the patient?
. Ans. b. Laser photocoagulation of both eyes According to ETROP (early treatment for ROP cooperative group) the high risk pre threshold disease (i.e. zone / any stage plus (A)disease; or zone 1/stage 3: or zone 2, stage 2/3 plus ROP) is treated by laser photocoagulation."Retrolental fibroplasia/ Retinopathy of prematurity is a bilateral proliferative retinopathy occurring in premature infants (<32 weeks / <1.5 kg) exposed to high concentration of 0,, during the first 10 days of life. All the babies fulfilling above criteria should be screened with indirect ophthalmoscopy between 32-36 weeks post conceptionQ. The goal of treatment of threshold ROP is to prevent any retinal detachment or scarring and optimization of visual outcome. So laser photocoagulation of avascular immature retina is recommended in infants with threshold disease. According to ETROP (early treatment for ROP cooperative group) the high risk pre threshold disease (i.e. zone 1 any stage plus (+)disease; or zone 1/stage 3; or zone 2, stage 2/3 plus ROP) is treated by laser photocoagulation."Management of Retinopathy of Prematurity (ROP)Classification of ROP by Anatomic Location (Zone)* For the purpose of defining the anteroposterior (AP) location of ROP the retina is div ided into 3 concentric zones centred on optic disc.* The centre of retinal map for ROP is optic disc not the mcula as in other maps.* Since there is a direct correction between severity of disease and amount of avascular retina the location of the border between vascularized and avascular retina is an important prognostic sign.* The most anterior normal retinal vascularization is identified and is assigned a zone.Zone IMost posterior circular zone with optic disc as centre and twice the disc- fovea (or centre of macule) distance as radius.Any ROP in this zone is very severe because of large peripheral areas of avascular retina.Zone IIIt is a doughnut shaped region that extends concentrically from the anterior border of zone 1 to within 1 disc diameter of the ora serrata nasally and to anatomic equator temporallyIts radius extends from centre of disc to the nasal ora-serrata. A circle is drawn with optical disc as centre and disc to nasal ora-serrata as radius. The area between zone 1 and this boundary is zone IIZone IIIIt encompasses the residual temporal crescentshaped retina anterior to zone 2. Clinical Assessment/Classification based on Severity (Stage) of diseaseStageFeature1(1)* Demarcation line: It is appearance of a thin, flat, white (grey) tortuous line (border) at the junction of mature vascularized retina posteriorly and immature avascular retina anteriorly. * It runs roughly parallel with the ora-serrata and is more prominent in temporal periphery.* It is seen at the edge of vessels dividing the vascular from avascular retina i.e. the abnormal branching or arcading of vesseiss lead upto the line.II (2)* Ridge: Demarcation line acquires a volume to form a pink or white elevation or ridge of thickened tissue that has height, width and extends above the plane of retina.* Blood vessels enter the ridge and small isolated neovascular tufts (popcorns) may be seen posterior to it.III (3)* Extraretinai fibre vascular proliferation (vessels growth into and above the ridge) characberizes stage 3.* The fibrovascular proliferation may extend from the ridge into the overlying vitreous and cause vitreous haemorrhage.IV (4)* Partial or subtotal retinal detachment: due to traction exerted from contraction of fibrovascular proliferation.* 4A = Extra foveal (without fovea 1 involvement)* 4B = Foveal (with foveal involvement)V (5)* Total funnel shaped retinal detachment* In premature infants weighing < 1200 gm, PaO. of umbilical artery should be monitored, levels of50-100 mmHg being safe.* Premature infants should not be placed in incubator with an O, concentration of more than 30%* If minor signs of ROP are noticed, examination should be repeated at 1, 3, and 6 months and every 4 months upto the age of 4 years with the aim of diagnosing early retinal holes or retinal detachment.* Treatment involves ablation of avascular retina by laser photo coagulation {instrument of choice: and a standard of treatment in management of other vasoroliferative retinopathies associated with diabetes, sickle cell anemia and retinal vascular occlusion also).* Laser therapy has largely replaced cryotherapy because of superior visual and anatomical outcomes and induces less myopia.* Few indications for cryotherapy (over laser) include poor fundus visibility, lack of laser availability and physician's unfamiliarity with indirect laser retinoplexy procedure.* Intravitreal anti-VEGF agents as bevacizumab are also tried.Stage, ActivityManagementStage 1, 2 and 3 included in low risk (type 2) prethreshold ROP* Weekly or biweekly screeningStage 1, 2 and 3 included in high risk (type 1) prethreshold and /or Threshold ROP* Laser photocoagulatton (Treatment of choice) CryotherapyStage 4A* Laser or cryotherapy + sclera bucklingStage 4B and 5* Lens sparing pars plana vitrectomy
Examine the patient after 1 week
Laser photocoagulation of both eyes
Laser photocoagulation of worse eye, follow up of other eye
Vitreoretinal surgery