Childhood blindness due to ROP Childhood blindness due to ROP - PowerPoint PPT Presentation

Childhood blindness due to ROP Childhood blindness due to ROP

Number of blind children/10 million pop, by cause and level of development by cause and level of development

Proportion of blindness due to ROP, by World Bank region by World Bank region

Estimates of numbers blind from ROP, b World Bank region Being re ised by World Bank region. Being revised… Total >50 000 >50,000

Proportion of blindness due to ROP, b infant mortalit rates by infant mortality rates

ROP blindness – likely risk using IMR as a proxy 2010 proxy 2010 ≤ 8/1000 Low risk of ROP blindness – good neonatal care and screening 9 – 60/1,000 High risk of ROP blindness – inadequate care and screening ≥ 61/1,000 Low risk of ROP – neonatal care not well developed

Retinal vascularisation during development 16 weeks GA 26 weeks GA 36 weeks GA 40 weeks GA

Pathogenesis of ROP Relative hypoxia

Peripheral retinal hypoxia drives the ne new blood vessel growth blood essel gro th

Classification of ROP u Site (zones and clock hours) u Severity (Stages) Severity (Stages) u Signs of BRB breakdown (“plus disease”) u Scarring Scarring

Classification of ROP - by zone (site) y ( ) Zone 3 Zone 2 Zone 1

Classification of ROP - by stage (severity) Stage Features I Demarcation line II Ridge III Fibrovascular ridge IV Subtotal retinal detachment V Total retinal detachment

Stage 1 demarcation line Stage 1 demarcation line

Stage 1 demarcation line

Stage II ROP - ridge ridge Stage II ROP

Stage II ROP Stage II ROP

Stage III - early early Stage III

Stage III

Stage III ROP Stage III ROP

Stage III ROP g

Stage III ROP Stage III ROP

Courtesy Ells

Courtesy Ells

Stage 4 – subtotal retinal detachment Courtesy Azad

Stage 4 – subtotal retinal detachment Courtesy Azad

Stage V - total retinal detachment with open funnel with open funnel

Stage V - total retinal detachment with closed funnel ith l d f l

Stage V - inoperable retinal detachment p g

End stage eye blind from ROP y g

Child blind from ROP

Cicatricial disease with dragged vessels

Nat ral histor of ROP Natural history of ROP u Disease starts 4-7 weeks after birth, and progresses over the following few weeks u Stage I and II disease - spontaneous regression common u Stage III “plus” disease (threshold disease) - 50% progression to retinal detachment u Stage IV and V disease - blinding

Classification of ROP Classification of ROP - other other u “Plus” disease: denotes breakdown of blood-ocular barriers, with pupil rigidity, dilated tortuous retinal vessels, vitreous haze u Threshold disease: 5 + continuous clock hours of Stage III “plus” disease or 8 hours in total of Stage III “plus” disease 8 h i t t l f St III “ l ” di

“Plus” disease in posterior pole Plus disease in posterior pole

Courtesy Ells

Changes to classification (2005) C a ges to c ass cat o ( 005) u Pre-plus disease u Clarification of how to assess if disease Cl ifi ti f h t if di is in zone 1 u Aggressive, posterior ROP (AP-ROP)

“Pre-plus” disease p

New stage: Aggressive posterior ROP (AP ROP) ROP (AP-ROP) Courtesy Ells

New stage: Aggressive posterior ROP (AP-ROP) ROP (AP-ROP)

Indications for treatment - old Indications for treatment old Threshold disease: A total of 8 discontinuous clock hours of stage III “plus” disease, or 5 or more continuous clock hours

Indications for treatment – new (earlier in the course of the disease) the course of the disease) Type 1 pre-threshold disease: – Zone 1, any ROP with plus disease ( ≥ 6 hours) – Zone 1, Stage 3 ROP +/- plus – Zone 2, Stages 2 or 3 with plus disease ( ≥ 6 h hours) )

Rates of threshold disease ates o t es o d d sease u Vary, depending on – Case mix – Neonatal care and survival of most at risk – Screening criteria u <1% in some UK units (<1,500g and/or <32 weeks) u 15% in middle income countries (same criteria)

Treatment of threshold disease Treatment of threshold disease Aim: confluent treatment of avascular retinal periphery with cryo or laser avoiding long ciliary vessels and with cryo or laser, avoiding long ciliary vessels and ridge

Courtesy Ells

Indirect laser treatment

Baby receiving cryotherapy Baby receiving cryotherapy

Peripheral retinal cryo with laser Peripheral retinal cryo with laser

Disease regression after treatment Disease regression after treatment

Plus disease resolves with treatment Before treatment At 2 weeks At 4 weeks Courtesy Ells

Schematic representation of blindness due to ROP in the West since 1940 d e to ROP in the West since 1940 Oxygen restriction Survival LBW babies “first “second epidemic” epidemic” Blindness due to ROP 1940 1950 1960 1970 1980 1990 2000 1940 1950 1960 1970 1980 1990 2000 BW: 1,000-1,500 gms 600-900 gms

Risk factors during the “first epidemic of ROP” in the West (1940s and 1950s) ROP” in the West (1940s and 1950s) u Supplemental oxygen u No monitoring of blood gases u Birth weight: mean 1,300 (800 – 3,400 gs)

Risk factors during the “second epidemic of ROP” in the West (1970s on ards) of ROP” in the West (1970s onwards) u Extremely low birth weight (<1,000 gms, av 750 ( 1 000 0 gms) u Extreme prematurity (<30 weeks GA: av 25 Extreme prematurity (<30 weeks GA: av 25 weeks) u Small for gestational age (SGA) u Small for gestational age (SGA) u Poor post natal weight gain u Fluctuating blood gases - hyperoxia/hypoxia g g yp yp u Factors predisposing to the “oxygen radical disease of neonatology” u [Ocular factors]

Characteristics of babies with “severe” ROP in UK USA and Canada ROP in UK, USA and Canada U K s c re e n in g criteria it i Full term Gilbert et al. Paediatrics 2005 115 518-525

Characteristics of babies with “severe” ROP in low/middle income countries Argentina (C ) 4000 Argentina (G) Argentina (L) Argentina (L) Argentina (M) Argentina (P) Argentina (T) 3500 Brazil Chile Colombia Cuba 3000 Ecuador I di India (D) (D) India (H) weight (gms) India (M) 2500 Lithuania (K) Lithuania (V) Peru SS Peru Public 2000 Vietnam Birth w 1500 1000 500 0 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 Gestational age (weeks) Gilbert et al. Paediatrics 2005 115 518-525

Varying neonatal care in India - variation in exposure to risk factors for ROP

…variation in risk Courtesy Ells

Risk factors during the “third epidemic of ROP” in middle income co ntries of ROP” in middle income countries Historical perspective of ROP Historical perspective of ROP 1940-50s 1960-70s 1980s-present 1st epidemic 2nd epidemic Risk factors for ROP: Risk factors for ROP: - prematurity + ++ ++++ - low birth weight + ++ ++++ - high oxygen ++++ +++ + illness factors illness factors + + + + +/- +/ - High mortality Mod mortality Low mortality <1,000 gms No ROP ROP + ROP +++ Improved I d V Very low l Low mortality 1,000-1,500 gms Survival mortality ROP ++ ROP +++ No ROP Poor Moderate Excellent Level of neonatal care Level of neonatal care 3rd epidemic encompasses babies represented provided in all three columns

Risk factors during the “third epidemic of ROP” in middle income co ntries of ROP” in middle income countries • Mixture of the first and second epidemic • Different risk factors probably important in p y p different clinical settings • May be varying susceptibility in different racial groups - blacks less susceptible

Summary of risk factors, and babies at risk of ROP babies at risk of ROP • Varies, depending on neonatal outcomes: – good neonatal outcomes: risk factors and babies g at risk similar to the West (i.e. extremely low birth weight; extreme prematurity; fluctuating oxygen levels etc) levels etc) – poor neonatal outcomes: risk factors similar to first epidemic (i.e. poorly controlled oxygen levels in more mature babies)

Prevention of blindness in children due to ROP due to ROP • Primary prevention: – prevention of the disease from occurring in the first place first place • Secondary prevention: – early identification and treatment to prevent the – early identification and treatment, to prevent the consequences of the disease • Tertiary prevention: y p – Interventions to restore function

Primary prevention of ROP - 1 Primary prevention of ROP - 1 • Prevent preterm birth: – avoid unnecessary Caesarian sections – good antenatal care d t t l – prevent teenage pregnancies (26% mothers <20 years old in a recent screening prog study <20 years old in a recent screening prog study in Ecuador) – prevent multiple birth (e.g. from IVF) prevent multiple birth (e.g. from IVF) – good obstetric care