Outcome-based management of retinopathy of prematurity. Multicenter Trial of Cryotherapy for Retinopathy of prematurity Cooperative Group

Fluorescein Angiography Findings in Treatment-Naive Premature Infants with Retinal Vascular Immaturity and Persistent Avascular Retina

PURPOSE

To evaluate the fluorescein angiography (FA) findings in eyes with spontaneously regressed retinopathy of prematurity (ROP).

METHODS

Fluorescein angiography images of 162 eyes of 81 treatment-naive infants who underwent FA due to retinal vascular immaturity and persistent avascular retina (PAR) despite exceeding postmenstrual age of 60 weeks were analyzed retrospectively. Disc diameter (DD), optic disc-to-fovea distance (FD), the length of temporal retinal vascularization (LTRV), and the length of measurable temporal avascular retina distance (LMTAR), were quantitatively measured.

RESULTS

The mean gestational age and FA imaging age were 29.39 ± 3.13 and 86.51 ± 24.80 weeks postmenstrual, respectively. The mean ratios of LTRV/FD and LMTAR /DD were 4.47 ± 0.36 and 2.21 ± 1.01, respectively. Pigmentary changes were detected in the peripheral retina in 21% of the eyes. There was at least one angiographic finding in 88% of the eyes, but these findings were usually mild. Based on the FA findings, laser photocoagulation was performed to the peripheral avascular retina in ten eyes of five patients.

CONCLUSION

Even in larger preterm infants and without severe retinopathy and anti-VEGF treatment, PAR and peripheral pigmentary changes may be detected, and mild angiographic vascular activity may continue. These findings may lead to late-onset retinal pathologies that may threaten vision. In eyes with PAR, follow-up with FA and prophylactic laser application may be applicable. Further investigation is required for this topic.

Inter-eye comparison of retinal vascular growth rate and angiographic findings following unilateral bevacizumab treatment

PURPOSE

To compare retinal vascularization progression rate, final retinal vascularization, and fluorescein angiography (FA) findings in infants who received intravitreal bevacizumab (IVB) treatment in one eye and with spontaneous regression in the other eye.

METHODS

Thirty eyes of 15 infants who underwent IVB in one eye due to asymmetric retinopathy of prematurity, and who had pre-treatment fundus photographs and fluorescein angiography images were included in the study. Horizontal disc diameter (DD), optic disc-to-fovea distance (FD), and the length of temporal retinal vascularization (LTRV) distance were measured by evaluating pre-treatment and FA images.

RESULTS

The mean ages at the time of treatment and FA were 40.38  ±  3.35 and 68.72  ±  10.52 weeks postmenstrual age, respectively. The pre-treatment LTRV/FD ratio was 3.11  ±  0.41 in the treated eyes and 3.26  ±  0.43 in the non-treated eyes (p  =  0.053). The final LTRV/FD ratio was 4.23  ±  0.38 in the treated group and 4.33  ±  0.37 in the non-treated group (p  =  0.286). Staining of the vessels, hyperfluorescent focus, and irregular branching of the vessels were similar between the groups, respectively (p  =  1.000; p  =  0.250; p  =  0.625).

CONCLUSION

The progression rate of retinal vascularization and angiographic findings were similar between the treated eyes and the non-treated eyes. Our study suggests that incomplete retinal vascularization in eyes treated with anti-vascular endothelial growth factor (VEGF) is due to the nature of the disease, and anti-VEGF treatment was not to cause cessation in vascular progression.

Advances in understanding and management of retinopathy of prematurity

The understanding, diagnosis, and treatment of retinopathy of prematurity have changed in the 70 years since the original description of retrolental fibroplasia associated with high oxygenation. It is now recognized that retinopathy of prematurity differs in appearance worldwide and as ever smaller and younger premature infants survive. New methods are being evaluated to image the retina, diagnose severe retinopathy of prematurity, and determine windows of time for treatment to save eyes and improve visual and neural outcomes. New treatments to promote physiologic retinal vascular development, vascular repair, and inhibit vasoproliferation by regulating proteins involved in vascular endothelial growth factor, insulin-like growth factor, or erythropoietin signaling. Reducing excessive oxidative/nitrosative stress and understanding progenitor cells and neurovascular and glial vascular interactions are being studied.

Length of day during early gestation as a predictor of risk for severe retinopathy of prematurity

PURPOSE

Fetal mice require light exposure in utero during early gestation for normal vascular development in the eye. Because angiogenic abnormalities in retinopathy of prematurity (ROP) are manifested in preterm infants, we investigated whether day length during early gestation was associated with severe ROP (SROP).

DESIGN

Single-center, retrospective cohort study.

PARTICIPANTS

We included a total of 343 premature infants (401-1250 g birth weight [BW], from 1998-2002): 684 eyes (1 eye each of 2 patients excluded) with 76 eyes developing SROP, defined as (1) classic threshold ROP in zone I or II, (2) type 1 ROP in zone I, or (3) in a few eyes, type 1 ROP in posterior zone II that was treated.

METHODS

For each infant, average day length (ADL) was calculated during different cumulative time periods and time windows after the estimated date of conception (EDC). Multiple logistic regression analysis (with generalized estimating equations to account for inter-eye correlation) was performed.

MAIN OUTCOME MEASURES

Association of ADL during early gestation with SROP.

RESULTS

In a model evaluating all 684 eyes with 76 eyes developing SROP, BW, gestational age, multiple births, race, per capita income in the mother's residence ZIP code, and ADL during the first 90 days after the EDC were factors associated with the development of SROP. Each additional hour of ADL (90 days) decreased the likelihood of SROP by 28% (P = 0.015; odds ratio [OR], 0.72; 95% confidence interval [CI], 0.55-0.94). In a model evaluating the subset of 146 prethreshold ROP eyes with 76 eyes developing SROP, each additional hour of ADL during the first 105 days after the EDC decreased the likelihood of SROP by 46% (P = 0.001; OR, 0.54; 95% CI, 0.37-0.78). Time windows when ADL was most closely associated with SROP were 31 to 60 days and 61 to 90 days after the EDC for the all eyes and the prethreshold ROP eyes models, respectively.

CONCLUSIONS

Higher ADL during early gestation was associated with a lower risk for SROP and may imply a role for prophylactic light treatment during early gestation to decrease the risk of SROP.

Outcome of eyes developing retinal detachment during the Early Treatment for Retinopathy of Prematurity study

OBJECTIVE

To describe the structural and visual outcomes at age 6 years of retinal detachment (RD) from retinopathy of prematurity (ROP) in the Early Treatment for Retinopathy of Prematurity (ETROP) study.

METHODS

Prospective multicenter nonrandomized series of infants with high-risk prethreshold ROP who developed an RD by 6 months corrected age treated with observation or vitreoretinal surgery.

RESULTS

Of 401 patients, 63 (89 eyes) experienced RD. Follow-up at age 6 years was available for 70 eyes (79%) of 49 surviving patients. The RDs were stage 4A in 28 eyes (40%), stage 4B in 14 (20%), stage 5 in 13 (19%), and not classified in 15 (21%). The macula was attached in 17 of 50 eyes (34%) after vitrectomy with or without scleral buckle, in 6 of 9 (67%) after scleral buckle only, and in 2 of 11 eyes (18%) observed. An attached macula at age 6 years after vitreoretinal surgery was present in 5 of 16 eyes (31%) with stage 4A, 6 of 10 (60%) with stage 4B, and 0 of 10 with stage 5. Favorable visual acuity (>20/200) was found in 6 of 70 eyes (9%); 5 had stage 4A, and 1 was not classified.

CONCLUSIONS

Macular attachment was achieved in approximately one-third of eyes with RD and favorable visual acuity in some eyes with stage 4A.

Stanford University network for diagnosis of retinopathy of prematurity (SUNDROP): 36-month experience with telemedicine screening

BACKGROUND AND OBJECTIVE

to report the 36-month experience of the Stanford University Network for Diagnosis of Retinopathy of Prematurity (SUNDROP) telemedicine initiative.

PATIENTS AND METHODS

retrospective analysis of the SUNDROP archival data between December 1, 2005, and November 30, 2008, to evaluate this diagnostic technology for retinopathy of prematurity (ROP) screening. A total of 230 consecutively enrolled infants meeting ROP examination criteria were screened with the Ret-Cam II (Clarity Medical Systems, Pleasanton, CA) and evaluated by the SUNDROP reading center at Stanford University. Outcomes included referral-warranted ROP, treatment-warranted ROP, and anatomic outcomes.

RESULTS

in the initial 36-month period, the SUNDROP telemedicine initiative did not miss any treatment-warranted ROP. A total of 230 infants (460 eyes) were imaged, resulting in 1,059 examinations and 10,921 unique images. Ten infants were identified with referral-warranted ROP: nine underwent laser photocoagulation and one regressed spontaneously. The sensitivity was 100% with a specificity of 99.5%. No patient progressed to retinal detachment or other adverse outcomes.

CONCLUSION

the SUNDROP telemedicine screening initiative for ROP has demonstrated high reliability for identification of treatment-warranted disease. All cases of treatment-warranted disease were captured. There were no adverse outcomes.

Cumulative illness severity and progression from moderate to severe retinopathy of prematurity

OBJECTIVE

To test cumulative neonatal illness severity (IS) and IS fluctuation as predictors of progression from moderate to severe retinopathy of prematurity (ROP).

METHODS

Data from research databases and medical record review were collected for infants from four neonatal intensive care unit (NICUs) admitted between 1995 and 2001 and diagnosed with prethreshold ROP. Cumulative neonatal IS measured using daily Scores for Neonatal Acute Physiology (SNAP) for the first 28 days of life, and IS fluctuation as assessed by summing changes between daily SNAP scores, were tested as predictors of progression to threshold ROP using logistic regression.

RESULTS

Infants progressing to threshold (n=79), compared to those not progressing to threshold (n=130), had significantly (P<0.05) lower gestational ages (25.2+/-1.1 versus 25.8+/-1.4 weeks), higher cumulative neonatal SNAP (255+/-77 versus 224+/-63 weeks) and had more severe hospitalizations as indicated by diagnoses and medical management. In regression analysis, gestational age, chronological age and presence of plus disease at first diagnosis of prethreshold were associated with development of threshold. After adjusting for these factors, cumulative neonatal SNAP was significantly associated with progression to threshold. However, addition of cumulative SNAP to the model only increased receiver-operating characteristic curve area from 0.77 to 0.78 (NS). Other factors, including SNAP fluctuation, were not associated with progression to threshold after adjustment using this model.

CONCLUSIONS

Cumulative neonatal IS, as measured by cumulative SNAP, is an independent risk factor for progression from moderate to severe ROP. However, cumulative IS does not enhance assessment of risk for ROP progression after adjusting for simpler clinical factors.

Multicenter trial of early treatment for retinopathy of prematurity: study design

The Early Treatment for Retinopathy of Prematurity (ETROP) study was a randomized, prospective multicenter trial comparing the safety and efficacy of earlier vs. conventionally timed ablation of the peripheral retina for the management of moderate to severe retinopathy of prematurity (ROP). Approximately 7000 infants with birth weights <1251 g were screened at 26 centers over a 2-year period to achieve the sample size of 401 consented infants for the randomized trial. In order to minimize treatment of eyes with ROP that were likely to undergo spontaneous regression of the disease, a risk analysis model, RM-ROP2, was used to select for inclusion in the randomized trial only prethreshold eyes that had a high risk of an adverse outcome. The primary outcome measure was grating visual acuity measured by Teller acuity card testing conducted by masked testers in eyes randomized to earlier treatment vs. eyes randomized to conventional management when infants were 9 months post-term. Results were categorized into favorable (>or=1.85 cycles/degree) vs. unfavorable (<1.85 cycles/degree). The secondary outcome measure was retinal structure, assessed by ophthalmological examinations conducted at 6 and 9 months post-term. Here we describe a unique approach used in the ETROP study to select high-risk prethreshold ROP eyes for randomization and details about design of the study. Study results indicated that earlier intervention in selected high-risk prethreshold eyes results in improved vision in premature infants with ROP.

Severe retinopathy of prematurity: longitudinal observation of disease and screening implications

PURPOSE

To test the effectiveness of our Canadian retinopathy of prematurity (ROP) screening guidelines as applied to high-risk premature infants.

STUDY DESIGN

Retrospective longitudinal cohort study.

SUBJECTS

A total of 969 infants were examined longitudinally between 1991 and 2000 and 46 of these infants screened were treated for severe ROP.

METHODS

Data from weekly ROP screening examination results were collected from a geographical area and analysed.

RESULTS

The average incidence of severe ROP requiring treatment in the population of premature infants eligible for screening was 48.3 per 1000. In all, 46 infants were treated in this cohort. The mean gestational age (GA) was 25.5 weeks of age and the mean birth weight was 750 g. The mean chronological age (CA) and postmenstrual age (PMA) at the time of first screening was 36 days and 30.7 weeks, respectively. The first identification of any ROP in this group was at a mean CA 60 days and PMA of 34.1 weeks. The mean CA and PMA of the first observation of stage 3 were 74 days and 36.3 weeks. The mean CA and PMA at the time of treatment were 86 days and 37.7 week.

CONCLUSIONS

Our observations and analysis indicate the following ROP screening recommendations: infants of 28 weeks of GA or less, infants with a GA between 28 weeks and 30 weeks should have a single 'spot examination' at approximately 37 weeks of PMA (or prior to discharge from hospital) to include possible outliers; infants born with a birth weight of 1250 g or less; initial screening examination should be at 31 weeks of PMA or 4 weeks of CA, whichever is later; in the presence of any active ROP, the infant should be followed every 1-2 weeks; and stage 3 should be followed at least every 7 days.

Telemedicine approach to screening for severe retinopathy of prematurity: a pilot study

PURPOSE

To evaluate the use of remote reading of digital retinal photographs in the diagnosis of severe (referral-warranted) retinopathy of prematurity (ROP) during longitudinal screening for ROP.

STUDY DESIGN

Prospective, longitudinal cohort study.

SUBJECTS

Forty-four consecutive premature infants at risk for ROP.

METHODS

All infants were examined longitudinally, over a series of examinations, by indirect ophthalmoscopy (gold standard) and digital photography using the RetCam-120 Digital Retinal Camera (Massie Research Laboratories Inc., Dublin, CA) equipped with an ROP lens. Images were stored and read remotely by a masked reader. Referral-warranted ROP was defined as ROP in zone 1, the presence of plus disease or the presence of any stage 3 ROP. We determined whether and when referral-warranted ROP was diagnosed for each eye, of each infant, on each examination, during the course of each of the infant's screening.

RESULTS

Severe (referral-warranted) ROP was diagnosed in 23 eyes by indirect ophthalmoscopy during their series of examinations. Digital photography had a sensitivity of 100% and a specificity of 96% in detecting referral-warranted ROP. The positive predictive value of digital photography was 92%, and the negative predictive value was 100%. In 87% of eyes, referral-warranted ROP was diagnosed by digital photography before or at the same time as indirect ophthalmoscopy.

CONCLUSIONS

Longitudinal remote reading of digital photographs using the RetCam-120 system has excellent specificity and sensitivity in detecting referral-warranted ROP. This pilot study has shown that remote reading of digital photographs has promise for telemedicine strategies in ROP screening.

Retinopathy of prematurity in infants with birth weights greater than 1250 grams

PURPOSE

To determine whether severe retinopathy of prematurity (ROP) occurs in infants whose birth weights exceed 1250 g.

METHODS

We retrospectively reviewed the medical records of 1118 premature infants with birth weights > 1250 g, who were referred for screening examinations for ROP, to determine the severity of ROP observed. We then cross-tabulated these data with each infant's estimated gestational age and birth weight. Finally, we applied currently recommended screening guidelines retrospectively to determine whether they would have identified infants who had developed severe disease and who were subsequently treated.

RESULTS

Stage 3 ROP was detected in infants with estimated gestational ages up to and including 32 weeks and birth weights up to and including 1874 g. A total of 26 of the participants received laser treatment for threshold ROP. Seven of these infants would not have been referred for screening according to current guidelines.

CONCLUSIONS

Current screenings guidelines may fail to detect severe ROP in larger, more mature infants.

Ophthalmological problems of the premature infant

Preterm infants are more likely than term infants to have significant abnormalities of all parts of the visual system leading to reduced vision. The most common problem is retinopathy of prematurity (ROP). The frequency and severity of this disorder is inversely related to gestational age. Damage ranges from minor to catastrophic. Preterm infants also have higher rates of amblyopia, strabismus, refractive error, and cortical visual impairment. The later problem is largely associated with neonatal brain injury. Years later, these children may develop glaucoma and retinal detachments.

Retinopathy of prematurity

Retinopathy of prematurity (ROP) is a relatively new condition. Only in the last 60 years have children survived who were born prematurely enough to have a significantly immature retinal vasculature. This article describes the classification and physiology of ROP, the interventions now available, and possible future therapies.

Retinopathy of prematurity outcome in infants with prethreshold retinopathy of prematurity and oxygen saturation >94% in room air: the high oxygen percentage in retinopathy of prematurity study

OBJECTIVES

To determine the rate of progression from prethreshold to threshold retinopathy of prematurity (ROP) in infants excluded from Supplemental Therapeutic Oxygen for Prethreshold Retinopathy of Prematurity (STOP-ROP) because their median arterial oxygen saturation by pulse oximetry (SpO2) values were >94% in room air at the time of prethreshold diagnosis and to compare them with infants who were enrolled in STOP-ROP and had median SpO2 < or =94% in room air.

METHODS

Fifteen of the 30 centers that participated in STOP-ROP elected to participate in the High Oxygen Percentage in Retinopathy of Prematurity study (HOPE-ROP) from January 1996 to March 1999. Infants were followed prospectively from the time prethreshold ROP was diagnosed until ROP either progressed to threshold in at least 1 study eye (adverse outcome) or resolved (favorable outcome).

RESULTS

A total of 136 HOPE-ROP infants were compared with 229 STOP-ROP infants enrolled during the same time period from the same 15 hospitals. HOPE-ROP infants were of greater gestational age at birth (26.2 +/- 1.8 vs 25.2 +/- 1.4 weeks) and greater postmenstrual age at the time of prethreshold ROP diagnosis (36.7 +/- 2.5 vs 35.4 +/- 2.5 weeks). HOPE-ROP infants progressed to threshold ROP 25% of the time compared with 46% of STOP-ROP infants. After gestational age, race, postmenstrual age at prethreshold diagnosis, zone 1 disease, and plus disease at prethreshold diagnosis were controlled for, logistic regression analysis showed that HOPE-ROP infants progressed from prethreshold to threshold ROP less often than STOP-ROP infants (odds ratio: 0.607; 95% confidence interval: 0.359-1.026).

CONCLUSIONS

The mechanisms that result in better ROP outcome for HOPE-ROP versus STOP-ROP are not fully understood. It seems that an infant's SpO2 value at the time of prethreshold diagnosis is a prognostic indicator for which infants may progress to severe ROP. When other known prognostic indicators are factored in, the SpO2 is of borderline significance.

The outcome of retinopathy of prematurity: screening for retinopathy of prematurity using an outcome predictive program

PURPOSE

The purpose of this study was to compare the calculated risk of progression to threshold retinopathy of prematurity (ROP) and risk of an unfavorable structural outcome using the computer program, RM-ROP, with the observed incidence for infants born at Jackson Memorial Hospital (JMH) and to determine how many children would have been treated unnecessarily if the threshold criteria for treatment were lowered on the basis of the clinical findings and RM-ROP risk calculations.

DESIGN

Noncomparative interventional case series.

PARTICIPANTS

All 292 surviving premature infants weighing 1250 g or less at birth and born at JMH between January 1, 1997, and December 31, 1998, were included in the study.

METHODS

Baseline demographic factors and data from sequential ophthalmic examinations were entered into the RM-ROP program for risk calculation. Infants reaching threshold disease received diode laser indirect photocoagulation of the avascular retina. Three-month follow-up was obtained for infants receiving laser treatment.

MAIN OUTCOME MEASURES

The development of threshold ROP and an unfavorable structural outcome, defined as a posterior retinal fold or posterior retinal detachment occurring within 3 months of threshold disease.

RESULTS

Thirty-eight eyes were diagnosed with threshold ROP, with 18 of 20 subjects having bilateral disease. Three-month posttreatment follow-up was obtained on all 20 children, with 19 having good structural outcomes. Thirty-two percent of eyes (12 of 38) reaching threshold never had a risk estimate greater than 0.10. However, only 6% of eyes (35 of 546) that did not reach threshold ever had a model predicted risk greater than 0.15. All right eyes with zone 1 prethreshold disease, 60% of those with zone 2 stage 2+ disease, and 23% with zone 2 stage 3 disease progressed to threshold ROP.

CONCLUSIONS

The similarity between the risk distributions for the Miami and the Multicenter Trial of Cryotherapy for Retinopathy of Prematurity study indicates the similarity in the populations with respect to risk factors identified as important by the model. The Miami data validated the model, with eyes reaching threshold having higher risks than eyes that did not. Actual risk estimates for eyes reaching threshold can be small. Changing the threshold criteria for treatment on the basis of various clinical and computer-generated prethreshold risk levels in our population would have resulted in the unnecessary treatment of many infants who never progressed to threshold disease. In the Miami population, if the model were used to manage an individual subject, close attention would have to be paid to small differences in risk. Although the RM-ROP software program may be a useful tool for following premature infants with ROP, the clinical examination remains the "gold standard."