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Early light reduction for preventing retinopathy of prematurity in very low birth weight infants

  1. Eliane C Jorge1,
  2. Edson N Jorge1,
  3. Regina P El Dib2,*

Editorial Group: Cochrane Neonatal Group

Published Online: 6 AUG 2013

Assessed as up-to-date: 31 OCT 2012

DOI: 10.1002/14651858.CD000122.pub2


How to Cite

Jorge EC, Jorge EN, El Dib RP. Early light reduction for preventing retinopathy of prematurity in very low birth weight infants. Cochrane Database of Systematic Reviews 2013, Issue 8. Art. No.: CD000122. DOI: 10.1002/14651858.CD000122.pub2.

Author Information

  1. 1

    Botucatu Medical School, Universidade Estadual Paulista (UNESP), Department of Ophthalmology, Otorhinolaryngology and Head and Neck Surgery, Botucatu, São Paulo, Brazil

  2. 2

    Botucatu Medical School, UNESP - Univ Estadual Paulista, Department of Anaesthesiology, Botucatu, São Paulo, Brazil

*Regina P El Dib, Department of Anaesthesiology, Botucatu Medical School, UNESP - Univ Estadual Paulista, Distrito de Rubião Júnior, s/n, Botucatu, São Paulo, 18603-970, Brazil. eldib@fmb.unesp.br. re.lucci@terra.com.br.

Publication History

  1. Publication Status: New search for studies and content updated (no change to conclusions)
  2. Published Online: 6 AUG 2013

SEARCH

 
Characteristics of included studies [ordered by study ID]
Braz 2006

MethodsDesign: randomised clinical trial
Multicentre (2 neonatal intensive care units)
Period: June 1995 to November 1996
Sample size: not reported
Follow-up: not reported


ParticipantsN = 226 randomised; 188 evaluated (control n = 93; trial n = 95)
Sex: control 61 male; trial 48 male
Age (mean): control 29.7; trial 30.2
Setting: neonatal intensive care
Inclusion criteria: infants < 1600 g birth weight or < 32 weeks gestation
Exclusion criteria: not reported


InterventionsPatching of both eyes from birth to 35 weeks postmenstrual age


OutcomesIncidence of retinopathy of prematurity


NotesAbstracts also published at an earlier stage (Lopes 1997 and Braz 1996)
We sent an email for the main author on 19 January 2012 asking about the generation of randomisation, allocation concealment, blinding of outcome assessment, exclusion criteria and sample size


Risk of bias

BiasAuthors' judgementSupport for judgement

Random sequence generation (selection bias)Unclear riskNot reported, although the authors stratified the patients in pairs within birth weight groups, with the first of the pair randomised blindly (per authors)

Allocation concealment (selection bias)Unclear riskNot reported

Blinding of participants and personnel (performance bias)
All outcomes
Low riskNot applicable

Blinding of outcome assessment (detection bias)
All outcomes
Unclear riskNot reported

Incomplete outcome data (attrition bias)
All outcomes
Unclear riskThe authors lost 16.81% from the total randomised patients (less than 20%). Per-protocol analysis

Selective reporting (reporting bias)Low riskNo evidence

Other biasLow riskNo evidence

Kennedy 1997

MethodsDesign: quasi-randomised clinical trial
Single centre (Parkland Memorial Hospital Special Care Nursery)
Period: August 1993 to June 1994
Sample size: alpha = 0.05, beta = 80%, log k of 0.15 log unit
Follow-up: 4 to 6 months corrected age


ParticipantsN = 71 randomised; 61 completed randomisation and 50 evaluated (24 goggles, 26 controls)
Sex: goggles 11 male; controls 12 male
Age (mean): goggles 27.8; controls 28.2

Setting: Parkland Memorial Hospital Special Care Nursery, USA

Inclusion criteria: infants < 1251 g birth weight or < 33 weeks

Exclusion criteria: congenital abnormalities of one or both eyes, lethal or irreparable congenital anomalies noted at birth and unlikely viability (infants not receiving full intensive care support)


InterventionsGoggles on both eyes within 6 hours of birth and continued until 31 weeks postmenstrual age or 4 weeks chronological age, whichever was later


OutcomesElectroretinograms (ERG) showed no differences

Acute ROP any stage was reported in 7/24 (29%) goggled infants and in 8/26 (31%) controls, and pre-threshold ROP occurred in one of each group


NotesPrimary outcome was electroretinogram; sample size was not determined to detect changes in ROP frequency


Risk of bias

BiasAuthors' judgementSupport for judgement

Random sequence generation (selection bias)High riskThe patients were randomised by a sequential method

Allocation concealment (selection bias)Low riskSealed opaque cards

Blinding of participants and personnel (performance bias)
All outcomes
Low riskNot applicable

Blinding of outcome assessment (detection bias)
All outcomes
Low riskThe assessors were blinded

Incomplete outcome data (attrition bias)
All outcomes
High risk11.5% and 4.1%, respectively, from the goggle and control groups were lost to follow-up for the ERG analysis

For the visual acuity exam, 46.1% and 50%, respectively, for the goggle and control groups were lost to follow-up

Selective reporting (reporting bias)Low riskNo evidence

Other biasLow riskNo evidence

Reynolds 1998

MethodsDesign: randomised clinical trial
Multicentre (3 centres in USA)

Period: July 1995 to March 1997

Sample size: incidence of any ROP, a detectable difference of at least 35%, a 2-sided alpha of 0.05, power of 80%, required 88 patients per group

Follow-up: 9 months after randomisation


ParticipantsN = 410 randomised (LIGHT-ROP 1999); 409 enrolled; 361 evaluated (18 goggles, 204 controls)

Sex: goggles 50.7% male; controls 56.4 male

Age (mean): goggles 27.2; controls 27.0

Setting: Buffalo, Dallas and San Antonio, USA

Inclusion criteria: infants < 1251 g birth weight, < 31 weeks gestation and admission of outborn infants at participating neonatal intensive care units within 24 hours of birth

Exclusion criteria: death before randomisation, lethal or irreparable congenital anomaly, major congenital abnormality of one or both eyes, non viability of infant, anticipated transfer of infant to nonparticipating unit prior to 40 weeks' postconceptional age and inability to begin goggle wear within 24 hours following birth


Interventions100% ultraviolet light and 97% light-reducing goggles worn in the intervention group only from within 24 hours of birth to 31 weeks postmenstrual age or 4 weeks chronological age, whichever was longer

The control group was exposed to the amount of light that was usual for the intensive care unit


Outcomes409 randomised (205 goggles, 204 controls); 46 died and 2 were lost to follow-up (17 in goggles and 31 in controls)

Among survivors evaluated 130/188 (69%) goggled infants developed any ROP and 121/173 (70%) of controls. Threshold ROP occurred in 4.7% of goggled vs 5.2% of controls (9 in each group). Poor visual outcome or need for cryo/laser treatment was not reported


NotesNo differences in ROP between groups

Also no difference in the subgroup that was goggled within 6 hours of birth

The difference in mortality between the 2 groups is not addressed by the authors and no apparent biological explanation is forthcoming

Note: authors used 'confirmed ROP' as the primary outcome in their report, but 'any ROP' is used here in order to be consistent with other reports in the analysis


Risk of bias

BiasAuthors' judgementSupport for judgement

Random sequence generation (selection bias)Low riskComputer-assisted randomisation protocol for each centre (block 2:6)

Allocation concealment (selection bias)Low riskThird party (co-ordinating centre)

Blinding of participants and personnel (performance bias)
All outcomes
Low riskNot applicable

Blinding of outcome assessment (detection bias)
All outcomes
Low riskExaminers were masked to study group assignment

Incomplete outcome data (attrition bias)
All outcomes
Low riskLess than 20% per group: 8.2% and 15.2% in goggles and control groups, respectively

Selective reporting (reporting bias)Low riskNo evidence

Other biasLow riskNo evidence

Seiberth 1994

MethodsDesign: randomised clinical trial

Single centre

Period: January 1987 to July 1991

Sample size: decrease incidence of ROP from 40% to 20%, alpha of 10% and a power of 80%, needed 62 patients per group

Follow-up: 6 months postpartum


ParticipantsN = 169 randomised (85 patched and 84 controls); 127 enrolled and evaluated (62 patched, 65 non patched)

Sex: 23 male in the patched group; 35 male in the controls

Age (mean): patched 29.3; controls 29.0

Setting: neonatal intensive care unit at the Women's Hospital of the University of Heidelberg, Germany

Inclusion criteria: ≤ 1500 g birth weight and ≤ 32 weeks gestation

Exclusion criteria: not reported


InterventionsBoth eyes were patched from the day of birth until 35 weeks postmenstrual age (= gestational age at birth plus chronological age in weeks)


OutcomesDeath occurred in 6 patched and 8 controls, 3 infants from the patched group were withdrawn by parents and 25 were lost because of transfer before complete evaluation (14 patched and 11 controls)

Similar numbers developed acute ROP: 26/62 patched and 25/65 controls

2 cases of poor ROP outcome causing blindness occurred, both in the patched group


NotesDespite a predetermined sample size, this study was stopped early because of a trend favouring the controls at an interim analysis


Risk of bias

BiasAuthors' judgementSupport for judgement

Random sequence generation (selection bias)Unclear riskNot reported

Allocation concealment (selection bias)Unclear riskNot reported

Blinding of participants and personnel (performance bias)
All outcomes
Low riskNot applicable

Blinding of outcome assessment (detection bias)
All outcomes
Low riskOphthalmologists masked to group when determining outcome

Incomplete outcome data (attrition bias)
All outcomes
High risk27% and 22.6%, respectively, for the patched and non-patched groups were lost to follow-up for the final analysis

Selective reporting (reporting bias)Low riskNo evidence

Other biasLow riskNo evidence

 
Characteristics of excluded studies [ordered by study ID]

StudyReason for exclusion

Ackerman 1989The comparison cohort was not randomly allocated (from a preceding time period)

Glass 1985Self controlled clinical trial

Hepner 1949No control group was reported

Hommura 1988The comparison group was a historical control cohort

Locke 1952Self controlled trial and case series report

Repka 1996Control cohort not randomly allocated; rates of ROP from 2 different nurseries with different ambient light levels

 
Comparison 1. Reduced light versus controls

Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size

 1 Acute ROP, all infants < 2001 g birth weight4726Risk Ratio (M-H, Fixed, 95% CI)1.00 [0.89, 1.13]

 2 Acute ROP, infants < 1000 g birth weight2270Risk Ratio (M-H, Fixed, 95% CI)0.96 [0.82, 1.13]

 3 Acute ROP, infants 1000 to 2000 g birth weight2218Risk Ratio (M-H, Fixed, 95% CI)1.00 [0.68, 1.49]

 4 Poor ROP outcome, all infants < 2001 g birth weight2488Risk Ratio (M-H, Fixed, 95% CI)1.13 [0.49, 2.61]

 5 Poor ROP outcome, infants < 1000 g birth weight162Risk Ratio (M-H, Fixed, 95% CI)10.24 [0.51, 203.83]

 6 Poor ROP outcome, infants 1000 to 2000 g birth weight181Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]