Visual acuity of eyes after vitrectomy for retinopathy of prematurity: follow-up at 5 1/2 years. The Cryotherapy for Retinopathy of Prematurity Cooperative Group

Evaluation of Treatment Models in the Treatment of Retinopathy of Prematurity

Objectives

This study aims to evaluate the treatment modalities applied for retinopathy of prematurity (ROP) and to determine the efficacy and results of treatment modalities.

Methods

Premature babies, who needed treatment for ROP and followed-up in the Neonatal Intensive Care Unit (NICU) of our hospital or external centers, were retrospectively evaluated between January 2012 and January 2017. According to the criteria determined by the International ROP committee, the zones and stages of the cases were recorded. In this study, patients were evaluated in three groups. Group 1: plus disease with any stage in zone 1, group 2: plus disease in zone 2, together with stage 2 or 3, group 3: classified as aggressive posterior retinopathy (APROP). The birth weight, gestational age, treatment weeks and treatments that were administered were recorded. Regression in plus disease, macular dragging and retinal detachment did not develop were evaluated as successful treatment.

Results

1746 preterm babies were examined. 65 (3.7%) preterm babies were included in this study, 31 female and 34 male. 126 eyes of preterm babies were intervened. The mean birth weight was 1159 (535-2200) grams, and the mean gestational age was 28.4±2.5 (24-34) weeks. Group 1 had 33 eyes (26.1%), group 2 had 71 eyes (56.3%), and group 3 had 22 eyes (17.4%). 94 eyes (74.6%) were treated once, 26 eyes (20.6%) were treated twice, 6 eyes (4.8%) received treatment three times. The first treatment was applied at 36±2.4 (32-41) weeks. The first treatment was performed with intravitreal bevacizumab (IVB) in 75.8% of group 1 and 95.5% of group 3, and with diode laser photocoagulation (LPC) in 78.9% of group 2. There was a significant correlation between birth week and birth weight and first treatment week. Re-treatment was applied to 32,8% in LPC group and 19.2% in the IVB group due to recurrence. 5 eyes which were applied LPC+IVB did not need any re-treatment. Stage 4a retinal detachment developed in both eyes of 1 patient from group 1. Macular traction was developed in 2 eyes of 1 patient in group 2. After the treatments, success in 122 eyes (96.8%) was obtained.

Conclusion

ROP can be controlled by convenient and effective treatment. Although conventional LPC is still the first treatment option for ROP, IVB alone or combination with LPC is a highly effective treatment option for zone 1 disease and APROP. IVB reduces the number of ROP treatments.

Evaluation of Potential Systemic Adverse Events Related to Fluorescein Angiography in Pediatric Patients

PURPOSE

To evaluate adverse events of fluorescein angiography (FA) in pediatric patients.

DESIGN

Single-institution retrospective chart review.

PARTICIPANTS

Patients 0 to 18 years of age who underwent FA between January 2010 and December 2015 at a single institution in the United States.

METHODS

Pediatric patients who underwent FA by 3 surgeons were included in the study. Patients with fewer than 24 hours of documented follow-up were excluded. Significant adverse events within 24 hours of FA were evaluated. Detailed intraoperative and perioperative physiological parameters, including heart rate, blood pressure, oxygen saturation, and ventilation parameters, in inpatients undergoing simultaneous examination under anesthesia were reviewed. Peri-injection effects of FA were evaluated by 2-tailed paired t test comparison of mean 5-minute preinjection and 5-minute postinjection physiological data.

MAIN OUTCOME MEASURES

Significant adverse events associated with FA.

RESULTS

One hundred fifteen patients with a total of 214 FA examinations were included. No significant adverse events were associated directly with FA. Comparison of mean 5-minute preinjection and postinjection physiologic parameters in 27 patients who underwent intravenous FA during EUA did not reveal significant changes associated with FA. A significant difference was found in average patient age between inpatient (2.5 years) and outpatient (10.7 years) FA (P < 0.00001). The youngest patients who underwent successful FA were 3.8 years old in the outpatient setting and 32 weeks' postmenstrual age in the inpatient setting. Patients younger than 3.8 years accounted for most (77.6%; n = 85) inpatient FA examinations. Excluding patients with a need or likely need for laser or surgery, the reasons for inpatient FA in patients older than 3.8 years included the lack of availability of outpatient ultra-widefield FA (UWFA) and more challenging situations in patients with developmental delay.

CONCLUSIONS

Fluorescein angiography was not found to be associated directly with systemic adverse events in pediatric patients in this study. Younger patients more commonly were found to require an inpatient FA, whereas older patients older than 4 years underwent outpatient UWFA.

Long-Term Anatomic and Visual Outcome Following Vitrectomy for Stage 4B and 5 Retinopathy of Prematurity

BACKGROUND AND OBJECTIVES

Surgical indications in stages 4B and 5 retinopathy of prematurity (ROP) are not universally accepted. The authors' purpose is to evaluate the long-term anatomic and visual outcomes of vitrectomy for retinal detachment (RD) associated with stages 4B and 5 ROP.

PATIENTS AND METHODS

Data of patients who consecutively underwent vitrectomy for stages 4B and 5 ROP from 1999 to 2013 were retrospectively reviewed and included grade of retinal attachment and visual acuity (VA) at the last follow-up.

RESULTS

Seventy eyes of 38 infants were included: 23 with stage 4B and 47 with stage 5 ROP. Lens-sparing vitrectomy was performed in 11 eyes, combined lensectomy / vitrectomy in 59 eyes. Mean follow-up was 8.5 years. Anatomic success was maintained in 41 eyes (58.5%), and among them, VA greater than 5/200 was achieved in 17 eyes (41.4%).

CONCLUSION

The long-term visual and anatomic success rates were encouraging for the surgical correction of RD associated with late stages ROP. [Ophthalmic Surg Lasers Imaging Retina. 2019;50:208-214.].

Current concepts and techniques of vitrectomy for retinopathy of prematurity

Retinopathy of prematurity (ROP) is a leading cause of childhood blindness worldwide. ROP screening and interventions (e.g., laser ablation and anti-vascular endothelial growth factor [VEGF] therapy) at the right time can reduce disease activity and prevent retinal detachment. However, sometimes, ROP is refractory to treatment, leading to tractional retinal detachment (TRD), requiring surgical intervention, such as vitrectomy. Vitrectomy for Stage 5 ROP (total retinal detachment) is beneficial in preventing total blindness in some patients. However, it has poor anatomical and functional results. Vitrectomy (lens-sparing vitrectomy, if possible) should be performed at Stage 4A ROP (partial TRD not involving the macula) because the anatomical and functional results are much better.

Paediatric retinal detachment: a review

Paediatric retinal detachment (PRD) is an uncommon and challenging disease; it differs from adult detachments in etiology, anatomical characteristics, management and prognosis. PRDs can be particularly challenging, even for the most expert paediatric surgeons due to the higher prevalence of total retinal detachments, late diagnosis and bilateral involvement with respect to those which occur in adulthood. Moreover, the anatomical success, when achieved, is frequently not related to a functional recover. Postsurgical adverse events, refractive errors and amblyopia may additionally undermine the final outcome. Up to date there are few reviews regarding the approach of retinal detachment in children, mainly dealing with rhegmatogenous retinal detachment. In this review, rhegmatogenous, retinopathy of prematurity-related and Coats'-related PRDs were considered. The available literature from the last decades were reviewed and summarized. Epidemiology, etiology and clinical presentation, together with therapeutic approaches and outcomes have been reviewed and discussed.

Current screening and treatments in retinopathy of prematurity in the US

Retinopathy of prematurity (ROP) is a complex disease characterized by an aberrant developmental retinal angiogenesis in preterm infants and can carry significant visual morbidity, including retinal detachment and blindness. Though large scale, randomized clinical trials have improved our understanding of the pathophysiology and progression of the disease, the management of ROP remains a challenge for ophthalmologists. This review addresses the up-to-date screening approach, diagnosis, and treatment guidelines for ROP in the US.

Early vitreoretinal surgery on vascularly active stage 4 retinopathy of prematurity through the preoperative intravitreal bevacizumab injection

PURPOSE

To evaluate the effect of early vitreoretinal surgery on vascularly active stage 4 ROP through the preoperative use of intravitreal bevacizumab.

METHODS

This was a retrospective study. Eighteen patients with vascularly active stage 4 ROP who underwent primary vitrectomy from April 2007 to March 2010 were enrolled. Twelve eyes from eight patients received one-time intravitreal injection of 0.625 mg bevacizumab 7 days prior to vitrectomy (bevacizumab group), and 11 eyes from 10 patients underwent the surgical procedure without bevacizumab (control group). Demographical information of all patients was recorded. The patients were followed up for 12-36 months after the surgery. The postmenstrual age at vitrectomy, surgical procedure, anatomical and visual outcome, adverse effects and surgical complications were compared.

RESULTS

There was no statistically significant difference between the two groups in gender, birthweight and gestational age. The bevacizumab group showed remarkable regression of vascular activity after the injection. The mean postmenstrual age at the time of vitrectomy was significantly earlier in the bevacizumab group (40 versus 47 weeks, p = 0.002) compared with the controls. The mean surgery time was shorter in the bevacizumab group (74.81 versus 101.70 min, bevacizumab group versus control, p = 0.002). At the final follow-up, all patients in the bevacizumab group achieved anatomical retinal attachment, compared with 70% in the control group. Eighty-eight per cent patients in the bevacizumab group obtained pattern vision, while it was 30% in the control group (p = 0.015).

CONCLUSION

Intravitreal bevacizumab administrated prior to vitrectomy effectively reduced active neovascularization in vascularly active stage 4 ROP patients, thus advancing the timing of vitrectomy and facilitating pars plicata vitrectomy (PPV).

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.

Efficacy of intravitreal bevacizumab for stage 3+ retinopathy of prematurity

BACKGROUND

Retinopathy of prematurity is a leading cause of childhood blindness worldwide. Peripheral retinal ablation with conventional (confluent) laser therapy is destructive, causes complications, and does not prevent all vision loss, especially in cases of retinopathy of prematurity affecting zone I of the eye. Case series in which patients were treated with vascular endothelial growth factor inhibitors suggest that these agents may be useful in treating retinopathy of prematurity.

METHODS

We conducted a prospective, controlled, randomized, stratified, multicenter trial to assess intravitreal bevacizumab monotherapy for zone I or zone II posterior stage 3+ (i.e., stage 3 with plus disease) retinopathy of prematurity. Infants were randomly assigned to receive intravitreal bevacizumab (0.625 mg in 0.025 ml of solution) or conventional laser therapy, bilaterally. The primary ocular outcome was recurrence of retinopathy of prematurity in one or both eyes requiring retreatment before 54 weeks' postmenstrual age.

RESULTS

We enrolled 150 infants (total sample of 300 eyes); 143 infants survived to 54 weeks' postmenstrual age, and the 7 infants who died were not included in the primary-outcome analyses. Retinopathy of prematurity recurred in 4 infants in the bevacizumab group (6 of 140 eyes [4%]) and 19 infants in the laser-therapy group (32 of 146 eyes [22%], P=0.002). A significant treatment effect was found for zone I retinopathy of prematurity (P=0.003) but not for zone II disease (P=0.27).

CONCLUSIONS

Intravitreal bevacizumab monotherapy, as compared with conventional laser therapy, in infants with stage 3+ retinopathy of prematurity showed a significant benefit for zone I but not zone II disease. Development of peripheral retinal vessels continued after treatment with intravitreal bevacizumab, but conventional laser therapy led to permanent destruction of the peripheral retina. This trial was too small to assess safety. (Funded by Research to Prevent Blindness and others; ClinicalTrials.gov number, NCT00622726.).

Late recurrence of retinal detachment following successful vitreous surgery for stages 4B and 5 retinopathy of prematurity

PURPOSE

To determine the incidence and possible causes of a late recurrence of a retinal detachment (RD) in eyes with stages 4B and 5 retinopathy of prematurity (ROP), in which the retina was once reattached by lensectomy and vitrectomy.

DESIGN

Retrospective, comparative case series.

METHODS

The medical records of 124 eyes of 99 infants and children <2 years of age at the time of initial vitrectomy, in which the retina had been reattached for at least 1 year, were reviewed. The incidence of a recurrence of the RD >1 year after the initial surgery for eyes at stage 4B ROP (42 eyes) was compared with that in eyes at stage 5 ROP (82 eyes). The onset and symptoms were evaluated.

RESULTS

A recurrent RD occurred in 2 eyes (5%) at stage 4B ROP and 18 eyes (22%) at stage 5 ROP (P = .01). The recurrence developed at 2 to 10 years of age (median, 4 years). Prior to the recurrence, clear signs of traction on the peripheral retina were detected in 10 eyes (50%): localized residual RDs in 8 eyes, and peripheral retinal breaks in 2 eyes. Dense vitreous hemorrhage was present in 5 eyes (25%) at the time of the recurrence.

CONCLUSIONS

The retina of eyes at stage 5 ROP is more vulnerable to a recurrence of the RD than in eyes at stage 4B after being attached by vitrectomy. The time of recurrence varies widely, and the presence of traction on the peripheral retina may be a sign of a recurrence.

Incidence of severe retinopathy of prematurity before and after a modest reduction in target oxygen saturation levels

BACKGROUND

Previous studies suggest that reducing target oxygen saturation levels to 85-93% decreases the incidence of severe retinopathy of prematurity (ROP). Our aim was to determine if a more modest reduction in target oxygen saturation levels also reduces ROP incidence.

METHODS

One neonatal intensive care unit instituted new oxygen saturation guidelines that changed target levels from the upper 90s to 90-96%. We conducted a retrospective cohort study to determine the proportion of eyes that progressed to (1) threshold or type-1 ROP and (2) stage 3. These proportions were compared between two groups of all eligible infants born up to 10 months before (higher oxygen group, n = 46) and up to 16 months after (lower oxygen group, n = 59) the policy change. Binomial regression was used to calculate relative risks adjusted for birth weight, gestational age, apnea, days of mechanical ventilation, and length of hospital stay.

RESULTS

Sixteen of 90 eyes (18%) in the higher oxygen group developed threshold or type-1 ROP versus 16 of 118 eyes (14%) in the lower oxygen group (adjusted relative risk = 0.66, 95% CI = 0.29, 1.51). Twenty-two of 88 eyes (25%) in the higher oxygen group developed stage 3 ROP versus 26 of 118 eyes (22%) in the lower oxygen group (adjusted relative risk = 0.76, 95% CI = 0.43, 1.37).

CONCLUSIONS

We observed a small but statistically insignificant reduction in the incidence of severe ROP after a modest reduction in target oxygen saturation levels to 90 to 96% in the first several weeks of life.

ANATOMICAL AND VISUAL RESULTS OF VITREORETINAL SURGERY FOR STAGE 5 RETINOPATHY OF PREMATURITY

PURPOSE

To provide a historical perspective on outcomes of surgery for infants with stage 5 retinopathy of prematurity (ROP) as performed by a single surgeon over a 24-year period.

DESIGN

Retrospective observational cohort study.

METHODS

SETTING

Clinical practice of the Charles Retina Institute.

PATIENTS

The 601 infants with stage 5 ROP in at least one eye who were referred for surgery between 1977 and 2001. Charts were reviewed for demographic data and postoperative anatomical and visual acuity outcomes in eyes that underwent surgery.

MAIN OUTCOME MEASURES

The postoperative anatomical status of the retina and visual function were assessed after surgery. Anatomical outcome was categorized as success (macula attached), partial success (macula detached), failure (total retinal detachment), or lost eye (opaque cornea, secluded pupil, or phthisis). Visual function was classified as>20/200, 20/200-5/200, hand movement, light perception, or no light perception. Multivariable logistic regression was used to explore relationships between outcomes and baseline characteristics.

RESULTS

Only a minority of eyes had prior cryotherapy (15%) or laser photocoagulation (7%) therapy. The mean follow-up was 44 months for the 956 eyes treated surgically. The 608 eyes with available follow-up data were classified as follows: 28% success, 5% partial success, 55% failure, and 11% lost eye. Visual function of light perception or better was achieved in 74% of the 183 eyes with data on visual acuity. Controlling for other baseline factors, early postpartum age at the time of surgery was a statistically significant predictor of failure/lost eye (OR=2.08, 95% CI 1.09-3.97) and no light perception (OR=5.13, 95% CI 1.45-18.14). Surgery for stage 5 ROP on the fellow eye was also a predictor of failure/lost eye (OR=2.38, 95% CI 1.39-4.08).

CONCLUSIONS

Surgery resulted in anatomical success for approximately one third of infant eyes with stage 5 ROP, and only a minority of eyes (8 of 183) achieved visual acuity better than 5/200. However, some initially successfully attached retinas redetached. Although this study is limited by follow-up and may represent a group of patients with a more vascularly active disease state due to the low proportion of patients with prior peripheral ablation, this cohort of infants provides results against which future interventions may be compared.

Lens-sparing vitrectomy for stage 4 and stage 5 retinopathy of prematurity

Purpose

To describe the results of lens-sparing vitrectomy for the correction of retinal detachment associated with retinopathy of prematurity (ROP) and its associated complications.

Methods

Seventeen patients who underwent a lens-sparing vitrectomy for stage 4 and stage 5 ROP with plus disease at Seoul National University Children's Hospital between 1999 and 2003 were enrolled in this study. The patients who had bilateral retinal detachment of ROP underwent a lens-sparing vitrectomy in one eye and a scleral buckling surgery or lensectomy-vitrectomy in the other eye. The patients who had a retinal detachment in one eye and a regressed ROP in the other eye underwent unilateral lens-sparing vitrectomies. A review of their preoperative clinical findings (including the status of retinal detachment and plus disease), post-operative results, and any complications encountered was performed.

Results

In 17 patients, the postoperative success rate of lens-sparing vitrectomy was 58.8%. However, lens-sparing vitrectomy as a treatment for stage 5 ROP (25.0%) produced more negative post-operative results than it did when used to treat either those for stage 4a (75,0%) or 4b (66.7%) ROP. Among the 10 eyes in which the retina was attached, form vision was shown in six eyes, light could be followed by three eyes, and no light perception was present in one eye. Intra- and post-operative complications included retinal break formation, cataracts, vitreous hemorrhages, and glaucoma in patients with stages 4b and stage 5 ROP.

Conclusions

Lens-sparing vitrectomy resulted in encouraging surgical outcomes in the correction of retinal detachment of ROP, especially in stage 4 patients. Therefore, a lens-sparing vitrectomy for stage 4 ROP patient may be beneficial, although it is still associated with some intra- and post-operative complications.

The ‘ideal’ management of retinopathy of prematurity

AIM

Retinopathy of prematurity continues to be a serious, but largely preventable cause of blindness and its detection and treatment is of increasing importance as survival rates of premature babies increase. This is particularly important in Medium Human Development Countries where the guidelines for detection used in the US or UK may not be appropriate.

METHOD

This report addresses identification of infants at risk for retinopathy of prematurity, detection, and treatment of serious disease, and what to do when treatment fails.

RESULTS AND CONCLUSIONS

Retinopathy of prematurity occurs almost exclusively in small premature babies, but the demographic characteristics of these babies vary depending on where they are born. Detection of serious retinopathy requires carefully timed examinations and the treatment criteria will continue to evolve as new therapies are developed. Timely detection and treatment of serious retinopathy of prematurity minimizes the likelihood of blindness, but it is not always successful.

COMPARISON OF RETINAL OUTCOMES AFTER SCLERAL BUCKLE OR LENS-SPARING VITRECTOMY FOR STAGE 4 RETINOPATHY OF PREMATURITY

PURPOSE

To compare anatomic outcomes after lens-sparing vitrectomy (LSV) or scleral buckle (SB) for stage 4 retinopathy of prematurity (ROP).

METHODS

Nonrandomized, retrospective study of infants consecutively treated for stage 4 ROP by LSV or SB. Outcomes were retinal attachment at 1 month of initial surgery and at the end of follow-up (6 months) and number of procedures to achieve retinal attachment. Exact chi2 methods determined significance, and student's t-test compared mean postmenstrual age and birthweight between the groups.

RESULTS

After one procedure, LSV (72%) was associated with retinal attachment more often than was SB (31%). At the end of follow-up, after one or more procedures, there was no difference in retinal reattachment rate between LSV or SB as the first procedure. There were no differences between the surgical groups by mean postmenstrual age and birthweight or severity of ROP determined by zone, clock hours of ridge elevation, or quadrants of plus disease.

CONCLUSION

This study supports the hypothesis that vitrectomy by LSV stops progressive stage 4 ROP. As an initial procedure, LSV was associated with retinal attachment more often than SB. Future prospective studies can determine the effects of LSV and SB on visual development in progressive stage 4 ROP.

RETINAL FEATURES PREDICTIVE OF PROGRESSIVE STAGE 4 RETINOPATHY OF PREMATURITY

PURPOSE

To determine the retinal features predictive of progressive stage 4 retinopathy of prematurity (ROP) after laser treatment for threshold ROP.

METHODS

Retrospective review of 72 eyes of 37 infants after laser treatment for threshold ROP between 1993 and 2002. Retinal features were abstracted from examinations made within 1 week of development of stage 4A ROP or 2 weeks after laser treatment in eyes with regressed threshold disease. Predictive features of progressive stage 4 ROP were determined using a generalized estimating equation model to account for within-subject variability.

RESULTS

The generalized estimating equation showed that vitreous state, ridge elevation of six or more clock hours, and two or more quadrants of plus disease predicted progressive retinal detachment, whereas two or more quadrants of neovascularization did not.

CONCLUSIONS

Progressive stage 4 ROP requiring surgical intervention was predicted by the absence of clear vitreous, ridge elevation of six or more clock hours, and two or more quadrants of plus disease, but not by neovascularization. These results may be useful in the management of eyes after laser treatment for threshold ROP.

A systematic review of anatomical and visual function outcomes in preterm infants after scleral buckle and vitrectomy for retinal detachment

OBJECTIVE

This article is a systematic review of the literature examining the anatomical and visual function outcomes after scleral buckle and/or vitrectomy for Stage 4 or 5 retinopathy of prematurity.

MATERIALS AND METHODS

The literature published between 1994 through May 2003 was reviewed via a computer search accessing MEDLINE via OVID. Eight applicable studies were retrieved and analyzed. The study designs were descriptive, retrospective, non-comparative, consecutive case series.

RESULTS

The postoperative anatomical outcomes varied dramatically between studies with retinal reattachment rates of 0.8% to 90%. Surgeries that achieved a 50% or higher rate of reattachment occurred primarily between 2 and 9 months of age. Surgeries that occurred between 7 and 11 months of age achieved a lower percentage of retinal reattachment. Further, the longer the duration of follow-up, the lower the percentage of retinas that remained attached. Most importantly, at least in these reports, the degree of retinal reattachment did not correlate well with the level of visual function. One report demonstrated no statistical correlation between visual and anatomical success. Poor visual outcomes were noted in both timely and delayed cases of surgical reattachment of the retina. Many of the reports described challenges in accurately measuring low levels of vision.

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: clinical aspects

There have been many major advances recently that have improved the identification and management of retinopathy of prematurity (ROP). This chapter describes the clinical features of ROP and then considers briefly the incidence and epidemiology of acute phase disease. This is followed by a discussion of the two ROP epidemics and ROP-induced disability in high, low and middle income countries, and how this has been impacted by treatment. The principles and specifics of screening for ROP are considered, focusing on certain topical issues such as whether one screening guideline suits all populations. Treatment has undergone several advances, so that now laser therapy has overtaken cryotherapy as the preferred mode of treatment, and treatment at an earlier stage is now being considered. Finally, the authors attempt to look into the future and wonder how the criteria for treatment will change, and whether innovations in ocular imaging will impact ROP screening in both high and middle income countries.

The management of retinopathy of prematurity

Retinopathy of prematurity (ROP) is a major problem in both highly developed countries and countries with emerging technology. The incidence of ROP has been stable over the last 2 decades despite improvements in neonatology. Threshold ROP occurs in about 5% of premature infants in the US with birthweights <1.25kg. Despite treatment, a sizable minority will become blind (up to 20 to 30%). The pathophysiology of ROP can be separated into 2 phases. Phase I is hyperoxia-vasocessation. Phase II is hypoxia-vasoproliferation. The former occurs immediately following premature birth. The provision of supplemental oxygen causes retinal hyperoxia, a down regulation of vascular endothelial growth factor (VEGF) and a consequent cessation of normal retinal vascularisation. Systemic factors and increasing retinal metabolic demands cause a shift to phase II when a relative retinal hypoxia develops. This hypoxia stimulates VEGF production, leading to renewed vascularisation. This can be the resumption of normal vascularisation or abnormal neovascularisation, depending on local retinal responses. The management of ROP begins with a reliable evidence-based screening protocol. All interested parties must cooperate in developing and implementing foolproof screening protocols. Hospital officials, nursery personnel, neonatologists and ophthalmologists all have areas of responsibility in ensuring adequate screening. ROP management involves prevention, interdiction and correction. Prevention includes: adequate prenatal care which minimises premature birth, and appropriate systemic intensive care which lessens the tissue hyperoxia/hypoxia swings. Pharmacological vitamin E supplementation has largely been abandoned and ambient light reduction has been shown to be ineffective. The value of inositol supplementation and angiogenesis inhibitors in preventing ROP is presently under investigation. Interdiction concentrates on ablation of the peripheral avascular retina, thus dramatically decreasing VEGF production. Both cryotherapy and laser photocoagulation are effective; however, unfortunately, poor outcomes persist despite treatment. Supplemental oxygen administration has so far proven ineffective in limiting ROP progression. Finally, correction focuses on vitrectomy/retinal detachment repair. While anatomically successful, this procedure is often unsuccessful in terms of restoration of vision (<5% success rate). In conclusion, despite improvements in neonatology, ROP, potentially leading to blindness, continues to be a common problem associated with prematurity. Future management success must concentrate on discovering new modes of treatment, especially prevention.

Cataract and phthisis bulbi after laser photoablation for threshold retinopathy of prematurity

PURPOSE

To describe the visual and structural outcome of eyes that developed a dense cataract after laser photoablation for threshold retinopathy of prematurity.

METHODS

A retrospective review of eight consecutive infants who developed dense cataract(s) after bilateral laser photoablation for threshold retinopathy of prematurity. Of the 10 eyes with cataract, five eyes were treated with a diode laser and five with an argon laser. The stage and zone of the retinopathy of prematurity, number of burns applied, time of onset of the cataract, clinical findings at the time of cataract surgery, and the course after cataract surgery were reviewed.

RESULTS

Six eyes had zone 1 disease and four had zone 2 disease. The mean number of burns applied per eye was 2532 +/- 856 (range, 1400 to 4500). A cataract was diagnosed a median of 3 [corrected] weeks (range, 1 to 28 weeks) after laser photoablation. Nine of the 10 cataracts were sufficiently dense to preclude a view of the fundus. All 10 eyes had clinical signs suggestive of an inflammatory or ischemic process that included one or more of the following findings: corneal edema, pupillary membrane, iris atrophy, depigmentation of ciliary processes, pigment on the anterior lens surface, posterior synechiae, hyphema, and shallow anterior chamber. Nine eyes underwent cataract surgery. Five of the 10 eyes had retinal detachment ranging in severity from stage 4A to stage 5 at the time of cataract surgery. Nine of the 10 eyes progressed to phthisis bulbi and no light perception.

CONCLUSIONS

A dense cataract developing in the eye of an infant after laser photoablation for threshold retinopathy of prematurity is associated with a poor visual prognosis. The constellation of associated clinical findings appears to be most consistent with anterior segment ischemia.

Avoidance and treatment of retinopathy of prematurity

Retinopathy of prematurity is a blinding eye disease of premature infants. It is increasing in incidence as more babies of lower birth weights survive. Although in the 1940s and 1950s the major predisposing factor was high oxygen exposure, the main risk factor now is birth weight less than 1,000 g. Retinopathy of prematurity can be classified into several distinct stages, which progress in a typical manner. Once the stage of threshold is reached, the eye has a 50% chance of becoming blind. At this stage, laser peripheral retinal photo ablation or peripheral cryo ablation may cause the neovascularization to regress and preserve vision. The treatment is not effective in all cases, however, and a large number of children continue to become blind each year because of this devastating disease. New microsurgical techniques such as lens-sparing vitrectomy and modified scleral buckle for tiny eyes have improved the outcome for some children. Prevention is the best hope to eradicate blindness caused by this disorder, and manipulations of the metabolic and neonatal intensive care unit environment are currently being studied.

Scleral buckling surgery for active stage 4A retinopathy of prematurity

OBJECTIVE

To examine the effectiveness of scleral buckling surgery for active stage 4A retinopathy of prematurity.

DESIGN

Retrospective noncomparative case series.

PARTICIPANTS

Eight eyes of seven infants were examined. All except one had previous peripheral ablation (cryotherapy-laser) but retinal detachment was actively progressing.

INTERVENTION

Scleral buckling surgery was performed by one surgeon.

MAIN OUTCOME MEASURES

Anatomic retinal status and visual acuity outcome after average follow-up of 23 months were measured.

RESULTS

Six (75%) of eight eyes had a complete retinal reattachment (+/- macular ectopia) after a single buckling procedure. Two eyes progressed to stage 4B despite scleral buckling but after closed limbal vitrectomy with lensectomy and membrane peeling, the retinas were reattached.

CONCLUSIONS

Scleral buckling for stage 4A retinopathy of prematurity is an effective means of preventing further progression of retinal detachment. The authors believe that the effect of the buckle not only relieves vitreoretinal traction but also plays a role in preventing ischemia in the detached retina that alters the natural progression of the disease.

The incidence of ophthalmologic interventions in children with birth weights less than 1251 grams. Results through 5 1/2 years. Cryotherapy for Retinopathy of Prematurity Cooperative Group

OBJECTIVE

This study aimed to report the frequency of ophthalmologic surgical and medical therapies provided to children with birth weights less than 1251 g who had all stages of retinopathy of prematurity (ROP). In addition, this study aimed to report the initial age at which such procedures are provided and to report the frequency of cerebrospinal fluid shunts.

DESIGN

Observational case series with prospective data collection.

PARTICIPANTS

Children from the Multicenter Trial of Cryotherapy for Retinopathy of Prematurity (CRYO-ROP) with birth weights less than 1251 g served as subjects. Group A included 257 children from all 23 CRYO-ROP study centers who had threshold ROP, who had participated in the randomized trial of cryotherapy, and who had survived to age 1 year. Group B included 1208 children from 5 of the 23 study centers who had varying severity of ROP (69 had threshold ROP) and who had participated in a 5 1/2-year study of the natural history of ROP.

MAIN OUTCOME MEASURES

Investigators documented medical and surgical ophthalmologic interventions through age 5 1/2 years as well as cerebrospinal fluid shunting surgery for hydrocephalus through age 2 years.

RESULTS

Group A was composed of 257 children with threshold ROP who underwent 226 ocular interventions in addition to cryotherapy (0.9 intervention per child). The most common treatments performed on the randomized cohort of children were vitrectomy (26% of patients), lensectomy (18%), amblyopia therapy (20%), and strabismus surgery (10%). Cataract surgery not associated with vitrectomy was performed infrequently (2%) and was performed equally often in treated and control eyes. Amblyopia therapy was prescribed as often for treated as for control eyes. Cerebrospinal fluid shunts were placed in 11% of these children. Group B was composed of 1208 natural history patients who underwent 239 ophthalmologic interventions (0.4 intervention per child). Strabismus surgery was the most commonly performed procedure for the natural history cohort of children (6% of the children). Amblyopia therapy was prescribed for 7% of the natural history patients. Cerebrospinal fluid shunts were required by 3% of the natural history infants, more often in children with more severe ROP.

CONCLUSIONS

These premature infants underwent a large number of ophthalmologic treatments during the first 5 1/2 years of life. The long-term costs of both extreme prematurity and ROP include not only the initial ablative therapy for ROP and societal loss due to blindness that still occurs in some cases, but also the ongoing costs of caring for eye problems.

Long-term form identification vision after early, closed, lensectomy-vitrectomy for stage 5 retinopathy of prematurity

PURPOSE

Form identification vision after early, closed, lensectomy-vitrectomy for retinopathy of prematurity (ROP) stage 5 open funnel retinal detachment is reported from a database that included 45 eyes of 27 infants. The focus of this report is the verbal responses at a mean age of 7.0 years for nine nonamblyopic (preferred) eyes of nine preterm infants with minimal developmental delay (good central nervous system function).

METHODS

All 45 eyes underwent initial cryotherapy for threshold ROP to the avascular retina to decrease the angiogenic stimulus (mean postconceptual age = 34.8 weeks) and subsequently underwent multiple cryotherapy sessions to the avascular retina and shunt with scleral buckling to decrease retinal traction (mean postconceptual age = 38.0 weeks). When tractional retinal detachment occurred with an open funnel, each eye underwent an early, closed, lensectomy-vitrectomy (mean postconceptual age = 45.7 weeks). The 34 eyes with a successful anatomic result were fitted with contact lenses as soon as possible after surgery.

RESULTS

The nine nonamblyopic eyes of nine preterm infants with minimal developmental delay had the following visual acuities using Allen figures or Snellen test types: one eye 20/80, one eye 20/200, two eyes 20/400, three eyes 20/800, and two eyes 20/ 1600.

CONCLUSION

These nine eyes support the thesis that form identification vision can be obtained by early vitrectomy for ROP stage 5 open funnel retinal detachments.