Retinopathy of prematurity by dr sonali paradhi mhatre

Retinopathy Of PrematurityPresented By : Dr. Sonali Mhatre

Introduction

• Retinopathy Of prematurity, is a disease of the developing retinal vasculature resulting from the interruption of normal progression of the newly forming retinal vessels.

• It is a multifactorial disorder with incidence increasing with decreasing gestational age.

• It is one of the most common causes of blindness & other visión errors in children.

• Earlier, it was known as Retrolental fibroplasia.

History of ROP

• 1940 – Retrolental Fibroplasia, first described by Terry.

• 1984 – Proved that RLF was associated with use of oxygen in newborn infants.

• 1951 - Heath suggested term “Retinopathy of Prematurity”

• Campbell (1952): relationship of intensive oxygen therapy & subsequent development of ROP.

• Kinsey: ROP was inversely proportional to birth weight.

Basic structure of

the eye

Structure of the Retina

Embryology

• Eye formation is first evident at the beginning of the 4th wk of gestation with the appearance of the optic sulci.

• The Retina, Iris and the optic nerve develops from the neuroectoderm.

• The Retina develops from the walls of the Optic cup, which is an outgrowth of the forebrain.

• During the embryologic and fetal periods, the two layers of the retina (i.e.) the Retinal pigment layer and the Neural retina are seperated by an Interretinal space.

• The photoreceptors – Rods & Cones, cell bodies of neurons are developed from the neuroepithelium.

Retinal Vasculature

Development

Pathogenesis

ROP

Stage 1 :

Arrest in vascular development

Stage 2 : Neovascularisation

Pathogenesis (cont…)

Stage 1

Initial insults like hypoxia, hypotension, hyperoxia

Vasoconstriction of retinal vasculature

Arrest in vascular development.

Stage 2

Excess angiogenic factors cause aberrant retinal vessel growth.

New vessels grow through the retina to the vitreous.

Extensive & severe extraretinal fibrovascular proliferation can cause

retinal detachment and abN retinal function.

Pathogenesis (cont…)

Risk Factors

• Extreme Prematurity• Apnea• Sepsis• Hypo/ hypercapnia• Intraventricular hemorrhage• Anaemia• Lactic acidosis• Exchange transfusión

• OXYGEN….!!!

Key Nomenclatures

• ICROP (1984 & 1987 )– Zone, Stage, Extent, Plus

• ICROP revisited (2005)– APROP– Pre plus

International classification of Retinopathy Of Prematurity

• Four features are evaluated:– Location– Severity– Extent– Presence or absence of plus disease

Locations

ICROP ( locations)

Zone 1 :

Imaginary circle with the optic nerve at the centre & the radius of twice the distance of optic nerve to macula.

ICROP ( locations)

Zone 2 :

Extends from the edge of zone 1 to the ora serrata on the nasal side of the eye and approximately half the distance to the ora serrata on the temporal side.

ICROP ( locations)

Zone 3 :

Consists of the outer crescent shaped área extending from zone 2 out to the ora serrata temporally.

ICROP ( severity)

Stage 1 :

A demarcation line appears as a thin White line that seperates the normal retina from the undeveloped avascular retina.

ICROP ( severity)

Stage 2 :

A ridge of fibrovascular tissue with height and width replaces the line of stage 1. It extends inward from the plane of the retina.

ICROP ( severity)

Stage 3 :

The ridge has extraretinal fibrovascular proliferation. Abnormal blood vessels and fibrous tissue develop on the edge of the ridge and extends into the vitreous.

ICROP ( severity)

Stage 4 : Partial retinal detachment.

Stage 4A : partial detachment not involving macula.

Stage 4B : Partial detachment involving the macula.

ICROP stages

ICROP (extent)

• Extent refers to the circumferential location of the disease.

• It is reperted as clock hours in the appropriate zone.

Plus disease

This refers to the presence of vascular dilatation and tortuosity of the posterior retinal vessels in atleast 2 quadrants.

This indicates a more severe degree of ROP & may be associated with iris vascular engorgement, pupillary rigidity and vitreous haze.

Pre - Plus diseaseVascular abnormalities of the posterior pole (mild venous dilatation or arterial tortuosity) that are present but are insufficient for diagnosis of a PLUS disease.

APROPAggressive Posterior ROP : uncommon, rapidly progressive, severe form of ROP, characterised by posterior location., & prominence of plus disease out of proportion to the peripheral retinopathy.

Threshhold ROPIf 5 or more contiguous or 8 cumulative clock hours(30 degree) of Stage 3 with plus disease in either zone 1 or 2 are present.

This is the level at which chances of blindness are atleast 50%.

Terminologies

Pre – threshhold ROP

1.) Type 1 pre-threshhold ROP:

a.) Zone 1, eyes with any ROP and plus disease or stage 3 with/without

plus disease.

b.) In zone2, stage 2 or 3 ROP with plus disease.

2.) Type 2 pre – threshhold ROP:

a.) In zone 1, stage 1 or 2 without plus disease.

b.) In zone 2, stage 3 without plus disease.

Terminologies (cont…..)

• Screening of at risk babies

• Diagnosis

• Treatment• Cryotherapy ( mostly outdated)• Laser treatment (gold standard)• Anti-VEGF (adjuvant) before laser and surgery• Surgery

– Rx of ROP related complications

• Post treatment follow up

• Rehabilitation

Management

Should be performed in all infants :

1.) weight <1500gm, <30 wks gestation.

2.) Weight >1500gm, with an unstable clinical course.

Screening to be done starting at 4 – 6 wks of age or 31-32 wks postmenstrual age.

Examination to be done every 2-3 wks till maturity is reached, if no disease found.

Infants with ROP – to be examined every 1 – 2 wks untill vessels are mature or disease threshhold has passed away.

Screening


• Diagnosis




• Rehabilitation

Management

Opthalmologic examination by an experienced examiner usually confirms diagnosis.

1.) Binocular indirect opthalmoscopy is

generally used.

Limitations- does not permit adequate assessment of ROP in retinal periphery.

Appropriate pain relieving steps like local anaesthetic eye drops and oral sucrose to be employed.

2.) RetcamWide angle digital paediatric retinal imaging system.• Avoids stress & expertise of I/O examination &

indentation, but as specific and sensitive as I/O• Useful for diagnosis, telemedicine &

documentation

Diagnosis


• Diagnosis




• Rehabilitation

Management

Treatment of ROP

• Cryotherapy significantly improves the outcome of severe ROP

• Probe placed trans-sclerally anterior to ridge in avascular zone.

• End point of cryotherapy is the appearance of mild whitening.

• 360 degrees circumference, under direct visualization avoid the ridge.

• Complications of cryotherapy – Eyelid edema, laceration of the

conjunctiva, and pre-retinal and vitreous haemorrhage as well as systemic complications like bradycardia, cyanosis and respiratory depression

Treatment - Cryotherapy

• Procedure of choice, being less invasive, less traumatic and causes less discomfort to the infant.

• Argon green and Diode red

• 1500 to 1800 spots, 100 mm size 1½ burn width apart.

• Entire avascular retina till ora, avoid the ridge.

• Complications of laser therapy – Burns in cornea and iris. Other

complications include cataract, and retinal and vitreous haemorrhage.

Treatment – Laser therapy

Treatment – Anti VEGF therapy

• Monotherapy – Single injections – Multiple injections for recurrence– Less desirable if periphery not perfused

• Adjunctive therapy – Injections to allow regression beyond Zone 1

• Laser for recurrent ROP • Anti-VEGF as a Bridge to laser peripherally

– Treatment after laser / cryotherapy failure

• Perioperative therapy before surgery – Reduce bleeding – Promote regression of neovascularization – Vitrectomy and scleral buckles

Treatment – Surgery

1.) Scleral buckling

1.

Treatment – surgery

2.) Vitrectomy

1.

Treatment – surgery


• Diagnosis




• Rehabilitation

Management

Prognosis

• 90% of stage 1,2 ROP – spontaneous regression.

• Approx 50% stage 3 –spontaneous regression.

• >stage3 : prognosis better with early laser photocoagulation , cryopexy.

• Long term sequelae may require follow up.

Complications

• Blindness• High myopia• Other refractive errors• Strabismus• Amblyopia• Astigmatism• Late retinal detachment• Glaucoma

Prevention

Interventions to prevent or limit the progression of ROP have been unsuccessful, further evaluation may be needed.

Experimental : Antioxidant therapies, such as vitamin E, D-penicillamine are being tried

Restricted Supplemental oxygen therapy Insulin-like growth factor-1(IGF-1)

Evidences

• CRYO-ROP (1980) - RCT

Peripheral Cryotherapy vs. Observation

Result : Cryotherapy superior to Observation.

• ET-ROP (2003) - RCT

Early peripheral laser vs conventional treatment – Finding: Observation advised until Type 1 or Regression

Peripheral laser better than conventional treatment for Type 1.

• BEAT-ROP - “Bevacizumab Eliminates the Angiogenic Threat in ROP”

RCT . Intravitreal Bevacizumab v/s Peripheral Laser (ETROP)

Summary - Bevacizumab reduced recurrence of ROP

Bevacizumab benefit over laser in Zone 1

Bevacizumab allowed continued peripheral vascularization into

avascular retina

Evidences (cont…)

• STOP-ROP (2000 ) ‘Supplemental Theraupetic Oxygen for Pretreshold Retinopathy of Prematurity trial randomized infants with prethreshold ROP to low (SpO 2 89–94%) or high (SpO 2 96–99%) oxygen targets.The high targets caused more pulmonary complications but no significant difference in the rate of progression to threshold ROP.

• BOOST 2 (2013) - In the Benefits of Oxygen SaturationTargeting trial, infants <30 weeks’ gestational age were randomized from 3 weeks or more after birth to target a low SpO 2 (91–94%) or high SpO 2 (95–98%) until they breathed air. A high oxygen saturation target increased the days of oxygen therapy and use of health care resources

• A Meta-Analysis and Systematic Review of the Oxygen Saturation Target Studies (2013) - RRs for mortality and necrotizing enterocolitis are significantly increased and severe retinopathy of prematurity significantly reduced in low compared to high oxygen saturation target infants. Until more studies have been performed, it is suggested to target SpO 2 in these babies at between 90 and 95%.

Take home message

• Retinopathy of prematurity is an important cause of blindness in premature infants.

• ROP is a disease of developing retinal vasculature.

• ROP development occurs in 2 stages – Vascular arrest f/b neovascularization.

• High risk factors include – Extreme prematurity, Hypo/hyperoxia, hypo/hypercapnia, sepsis, IVH, anaemia, apnea.

• ICROP (International classification of Retinopathy of prematurity ) classifies ROP based on 4 parameters – Zone, Severity, Extent, Presence of plus disease.

Take home message

• Screening plays a mojor role in ROP management.

Screening criteria :

1.) weight <1500gm, <30 wks gestation.

2.) Weight >1500gm, with an unstable clinical course.

ROP to be examined every 1 – 2 wks untill vessels are mature or disease threshhold has passed away.

Treatment includes – Cryotherapy, Laser treatment (gold standard), Anti-VEGF

(adjuvant) before laser and surgery.

Until more studies have been performed, it is suggested to target SpO 2 in these babies at between 90 and 95%.

Thank You

Retinopathy of prematurity by dr sonali paradhi mhatre

Healthcare

Transcript of Retinopathy of prematurity by dr sonali paradhi mhatre