Costenbader Lecture. The factor of time in retinopathy of prematurity

Incidence, timing and risk factors of type 1 retinopathy of prematurity in a North American cohort

BACKGROUND/AIMS

Early detection and timely treatment of type 1 retinopathy of prematurity (ROP) can reduce the risk of blindness. To evaluate the incidence, timing and risk factors of type 1 ROP in a large, broad-risk cohort of premature infants.

METHODS

Secondary analysis of data from the two Postnatal Growth and Retinopathy of Prematurity studies. Main outcomes are the incidence and timing of type 1 ROP.

RESULTS

Among 11 463 infants (mean birth weight (BW), 1095 g; mean gestational age (GA), 28 weeks), 677 (5.9%, 95% CI 5.5% to 6.3%) developed type 1 ROP. Rate of type 1 ROP decreased with larger GA (28.8% for GA ≤23 weeks, 0.2% for GA of 31-32 weeks) and no infants with GA >32 weeks developed type 1 ROP. Type 1 ROP was first diagnosed at a median postmenstrual age (PMA) of 36 weeks (range 30-46 weeks) or postnatal age (PNA) of 11 weeks (range 5-21 weeks). The mean PMA at diagnosis of type 1 ROP increased with GA (35 weeks for GA of 22-24 weeks, 41 weeks for GA of 29-30 weeks), but the mean PNA at diagnosis of type 1 ROP was similar (11-13 weeks) across GA of 22-29 weeks. GA and BW dominate the association (area under the receiver operating characteristic curve=0.87, 95% CI 0.86 to 0.88).

CONCLUSIONS

Type 1 ROP developed in about 6% of premature infants over wide time windows in terms of both PMA and PNA. BW and GA are the dominant risk factors for type 1 ROP, while other prenatal factors add minimal predictive power for type 1 ROP.

Time at treatment of severe retinopathy of prematurity in China: recommendations for guidelines in more mature infants

PURPOSE

To investigate the postmenstrual (PMA) age at treatment of severe retinopathy of prematurity (i.e. Type 1 prethreshold or threshold) in infants in a tertiary referral center in China.

PRINCIPAL FINDINGS

76.6% (359/469) of infants were treated for threshold disease. 67.5% (317/469) of infants had a birth weight (BW) of 1250 g or above and almost 30% (126) had a gestational age (GA) of 32 weeks or above. There was little difference in the characteristics of infants treated for Type 1 prethreshold or threshold ROP. After controlling for GA, PMA age at treatment was highest in infants with BW ≥2000 g (mean PMA 40.3±4.4 weeks, p<0.001); after controlling for BW, higher GA was associated with higher PMA at treatment (mean PMA 41.5 weeks for gestational age >34 weeks, p<0.001). For every three weeks increase in GA there was a two-week increase in PMA at treatment (R2 = 0.20, p<0.001). The time at treatment of Type 1 prethreshold disease was similar to that for threshold disease i.e. chronological age 5.6∓7.4 weeks, or PMA 34.1∓40.2 weeks but the lower end of the 95% confidence interval for chronological age for Type 1 prethreshold disease among infants with BW ≥2000 g was 3.7 weeks (i.e. before the recommended interval of 4∓6 weeks after birth).

SIGNIFICANCE

The Chinese guidelines regarding timing of the first examination are appropriate for infants with BW <2000 g, but more mature infants should be examined a little earlier, at 3 weeks after birth, in order to detect Type 1 prethreshold disease which has a better prognosis than threshold.

Retinopathy of prematurity in infants weighing less than 500 grams at birth enrolled in the early treatment for retinopathy of prematurity study

PURPOSE

To describe patient characteristics, classification, and onset of prethreshold retinopathy of prematurity (ROP), and ocular findings at 6 months corrected age in infants with birth weights <500 g who were enrolled in the Early Treatment for Retinopathy of Prematurity (ETROP) Study.

DESIGN

Multicenter randomized clinical trial.

PARTICIPANTS

Sixty-three infants with birth weights <500 g who developed ROP and were enrolled in the ETROP Study.

METHODS

Infants <1251 g at birth were logged at 26 study centers from October 1, 2000, to September 30, 2002, and underwent examinations for ROP. Infants who developed ROP and whose parents/legal guardians consented were enrolled in the ETROP Study. Infants who developed high-risk prethreshold ROP were randomized; 1 eye was treated early with peripheral retinal ablation and the other eye was managed conventionally, or, in asymmetric cases, the high-risk eye was randomized to early peripheral retinal ablation or conventional management. All eyes reaching prethreshold ROP were examined when infants reached 6 months corrected age.

MAIN OUTCOME MEASURES

Retinopathy of prematurity incidence, characteristics, and ocular findings among participants.

RESULTS

Thirty-four infants reached prethreshold or worse severity in 1 or both eyes. Retinopathy of prematurity was located in zone I in 43.3% of all prethreshold eyes, and plus disease was present in 46.7%. Median postmenstrual age for diagnosis of all prethreshold ROP was 36.1 weeks, but earlier (35.1 weeks) for eyes that developed high-risk prethreshold ROP. In the 27 surviving infants with prethreshold ROP, ophthalmic examination at 6 months corrected age showed a normal posterior pole in 22 (81.5%), a favorable structural outcome with posterior pole abnormalities in 4 (14.8%), and an unfavorable structural outcome (stage 4B) in 1 (3.7%). One infant developed amblyopia, 4 infants developed nystagmus, 4 infants developed strabismus, and 8 infants developed myopia >-5.00 diopters.

CONCLUSIONS

This is the first report on characteristics of prethreshold ROP in infants with birth weights <500 g. These infants are at high risk for developing prethreshold ROP, although many initially achieve a favorable structural outcome. They are at risk of developing strabismus, nystagmus, high myopia, and abnormal retinal structure and should therefore receive continued long-term follow-up.

FINANCIAL DISCLOSURE(S)

The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Update on retinopathy of prematurity: treatment options and outcomes

PURPOSE OF REVIEW

To evaluate and review the recent scientific literature on retinopathy of prematurity (ROP). Recent studies have shown advancement in treatment options in ROP as well as improved functional and structural outcomes. This review compiles some of these recent findings.

RECENT FINDINGS

New guidelines on ROP screening and treatment criteria have recently been developed and are now the standard of care for practitioners taking care of children having ROP. Recent advances in antiangiogenic therapies offer possible primary or adjunct treatment to the well established and effective laser treatment options. Follow-up of treated ROP patients informs us of the short-term and long-term complications requiring lifetime ophthalmology care.

SUMMARY

This review offers an update on the screening and treatment guidelines, new treatment options, and short-term and long-term complications in ROP.