Current concepts and techniques of vitrectomy for retinopathy of prematurity

A Narrative Review on Managing Retinopathy of Prematurity: Insights Into Pathogenesis, Screening, and Treatment Strategies

Retinopathy of prematurity (ROP) is a rare proliferative ocular condition that can happen in premature babies (born preterm <36 weeks) or who weigh <1.5 kg at birth (low birth weight babies). ROP is a major cause of childhood blindness. It is a premature disease since retina vascularization is completed only by 40 weeks of life. The survivability for preterm infants has increased owing to recent improvements in neonatal care during the past decade. As a result, the prevalence of ROP has risen concurrently. The abnormal development of blood vessels in the retina is the cause of this illness. It occurs in two phases, phases 1 and 2. Most preterm infants weighing <1.5 kg need supplemental oxygen for respiratory support at birth. This leads to the initiation of phase 1 (vasoconstrictive phase). Phase 1 is characterized by loss of maternal-fetal connection and hyperoxia due to supplemental oxygen therapy. Oxygen's vasoconstrictive and obliterative action is primarily observed in developing retinal vessels. The inhibition of vascular endothelial growth factor follows from this. Phase 2 (vasoproliferative phase) shows the dilatation and tortuosity of the bigger existing vessels together with neovascularization and proliferation of new vessels into the vitreous when the baby is shifted from respiratory support to room air. Now, the retina gets hypoxic, where the retina becomes more metabolically active but is yet minimally vascularized, leading to VEGF-induced vasoproliferation, which might result in retinal detachment. Patients with ROP face the danger of loss of vision. If correct and quick treatment is not provided, they might land into permanent blindness. Yet, ROP remains one of the most preventable causes of childhood blindness worldwide. Blindness caused by ROP can only be avoided if screening programs are readily available, pertinent, and appropriate. The initial stage in the therapy of ROP is the screening of premature neonates. Timely screening and management for ROP is important to avoid this irreversible loss of vision. The treatment is based on the severity of the disease. Management may include pharmacological interventions like intravitreal and anti-vascular endothelial growth factor and non-pharmacological interventions like laser surgery, vitrectomy, and scleral buckling. We conducted a thorough literature search of studies on pathogenesis, risk factors, classification, and various treatment options for retinopathy of prematurity in infants, using a mixture of pertinent keywords. Only those studies published in peer-reviewed journals between 2010 and 2023 and written in English were included. Duplicate studies, unavailable in full-text for free, or studies unrelated to our subject matter were excluded. After thoroughly evaluating the selected studies, the results were synthesized and presented narratively. This article sheds light on the pathogenesis of ROP, particularly its relation to oxygen use, screening, and potential therapeutic management of ROP. Today advances in screening techniques have improved the outcomes for infants with ROP. Still, ongoing research is needed to optimize management strategies and reduce the burden of this condition.

Vitrectomy Results for Stages 4 and 5 Retinopathy of Prematurity in Iraq

Background

Stage 4 and 5 retinopathy of prematurity (ROP) is a serious condition that may require surgical intervention at some point. Timely intervention is a key element and, with the peculiarity of eyes among this group that necessities a certain level of surgical standards, operations cannot be undertaken in any surgical eye center.

Aim of the Study

To recognize the outcomes of vitrectomy in Iraqi preterm babies with stage 4 and 5 ROP, and to study factors that might increase the risk of re-detachment in operated eyes.

Methods

A prospective cohort study undertaken from November 2020 to June 2023 for Iraqi preterm babies presenting with stage 4 and 5 ROP requiring surgical intervention. Each patient had a follow-up duration of 9 months. The primary follow-up outcome was anatomical success rate (flat versus detached), and the secondary outcome was to identify the postoperative complications.

Results

This study enrolled 19 children; 11 males and eight females (number of eyes operated on was was 31), with a mean gestational age of 29.4±2.1 weeks. There were six (19.4%) eyes that did not develop any complications, five (16.1%) eyes developed postoperative vitreous hemorrhage, five (16.1%) eyes developed cataract, three (9.7%) eyes underwent a second vitrectomy, and seven (22.6%) eyes developed secondary glaucoma. The surgical success rates were 90.9% for stage 4a, 57.1% for stage 4b, and 33.3% for stage 5a.

Conclusion

This study presented the first surgical experience for vitrectomy in children with retinopathy of prematurity in our country, and the results were encouraging with an overall surgical success rate of 64.5%, and 19.4% of eyes did not develop any complication until the 1-year of follow-up.

Long-Term Visual Prognosis of Patients Following Lens-Sparing Vitrectomy for Stage 4A Retinopathy of Prematurity

This study evaluated the long-term visual outcomes of patients in whom at least one eye underwent successful lens-sparing vitrectomy (LSV) for stage 4A retinopathy of prematurity (ROP). A retrospective chart review was conducted using the data of 61 eyes of 42 patients with a minimum 4-year follow-up after successful LSV, with or without anti-vascular endothelial growth factor (VEGF) therapy, and whose best-corrected visual acuity (BCVA) was measurable using Landolt rings at the final visit. The mean age at the final follow-up was 10.1 ± 3.3 years. Before LSV, all eyes underwent laser ablation therapy. Twenty eyes (32.8%) with high vascular activity received anti-VEGF therapy before LSV. The mean decimal BCVA at the final follow-up was 0.23 ± 0.26 (range: hand motion to 1.2). Twenty-three eyes (54.1%) had a decimal BCVA of ≥0.4. Among 49 phakic eyes at the final examination, the mean refractive error was -10.1 ± 5.0 D, with 37 eyes (75.5%) having high myopia (>-6.0 D). No significant differences were observed in terms of decimal BCVA and refractive errors between eyes with and without anti-VEGF therapy. Approximately half of the patients had a decimal BCVA of ≥0.4, despite myopic refraction after successful LSV for stage 4A ROP. LSV for stage 4A ROP seemed to be associated with good visual function, despite myopic refraction.

POSTERIOR TRACTIONAL MEMBRANES FOLLOWING ANTI-VASCULAR ENDOTHELIAL GROWTH FACTOR FOR RETINOPATHY OF PREMATURITY

PURPOSE

To report two cases of tractional membrane formation following treatment with anti-vascular endothelial growth factor therapy in infants with Stage-3 retinopathy of prematurity.

METHODS

Retrospective review of electronic medical record for historical information, clinical examination documentation, and imaging from fundus photography, retinal ultrasonography, and fluorescein angiography.

RESULTS

Two patients with Stage-3 retinopathy of prematurity, previously treated with laser therapy and intravitreal bevacizumab, were referred to our institution for tractional membranes. The first case is of a male infant with Zone-II disease that progressed to Stage 4A with evidence of inferotemporal tractional retinal detachment only in the left eye. The second case is of a male infant with stable Zone-I disease with an epiretinal membrane in the left eye.Pars plicata vitrectomy and membranectomy were required for both cases because of the concern for subsequent tractional retinal detachment.

CONCLUSION

Formation of tractional retinal membranes has been associated with anti-vascular endothelial growth factor therapy. These cases describe the formation of posterior tractional membranes after anti-vascular endothelial growth factor therapy. This potential ocular outcome should be considered when determining treatment plans for retinopathy of prematurity.

Structural outcome following surgery for stage 5 retinopathy of prematurity based on the new international classification: ICROP 3

PURPOSE

This study investigated the outcomes of vitrectomy for stage 5 retinopathy of prematurity (ROP) based on the International Classification of Retinopathy of Prematurity 3rd edition (ICROP 3), in which stage 5 ROP is divided into three subgroups.

METHODS

Fifty-four eyes of 34 patients with stage 5 ROP who underwent vitrectomy between 2004 and 2020 were retrospectively analyzed. Data including sex, gestational age and weight at birth, ICROP 3 subcategories, perioperative use of intravitreal bevacizumab injection (IVB) and laser photocoagulation, surgical procedure and complications, final retinal reattachment, and follow-up period were collected.

RESULTS

Complete retinal reattachment was achieved in 16 eyes (88.9%) with stage 5A and 13 eyes (39.4%) with stage 5B (P = 0.0003, Wilcoxon rank-sum test). Three patients with stage 5C were considered inoperable. Postoperative anatomical failure was significantly associated with stage (stage 5B vs. 5A; odds ratio, 17.986; 95% confidence interval, 3.712-148.502; P = 0.0001, multivariate logistic regression analysis). Intraoperative IVB was significantly associated with lower postoperative incidence of vitreous hemorrhage and glaucoma (P = 0.041, chi-square test).

CONCLUSIONS

Staging of preoperative anatomical features based on ICROP 3 is a useful predictor for final anatomical success. Intraoperative IVB might reduce postoperative complication risks.

Characteristics of Eyes Developing Retinal Detachment After Anti-vascular Endothelial Growth Factor Therapy for Retinopathy of Prematurity

BACKGROUND

We investigated the incidence and clinical characteristics of eyes showing retinal detachment (RD) after anti-vascular endothelial growth factor (VEGF) for retinopathy of prematurity (ROP).

METHODS

A retrospective chart review of 76 consecutive eyes of 45 patients (18 girls and 27 boys) with stage 3 ROP who received anti-VEGF therapy between January 2012 and August 2020 with a minimum follow-up of 6 months was conducted. Eyes were divided into two groups: the vitrectomy (V) group that required vitrectomy for RD after anti-VEGF therapy and the non-vitrectomy (non-V) group that did not require vitrectomy. Data were collected from patient charts, including sex, postmenstrual age (PMA) at birth, birth weight, PMA at anti-VEGF therapy, comorbidities, reactivation, examination interval, and subsequent vitrectomies.

RESULTS

The median PMA at birth was 24.7 (range, 22.1-29.3) weeks. Twenty-seven eyes (35.1%) exhibited ROP reactivation at 6.4 ± 3.1 weeks after anti-VEGF therapy. The V group included six eyes of five patients, all of whom exhibited reactivation and developed RD 10.1 ± 6.5 weeks after anti-VEGF therapy. The types of RD were conventional (classic) in two eyes and circumferential (unique to RD after anti-VEGF) in four eyes. Three eyes required repeated vitrectomy. All eyes, except one eye in the V group, achieved retinal attachment at the last examination. The non-V group included 70 eyes of 40 patients, of which 21 exhibited reactivation and were treated successfully with laser (17 eyes) or second anti-VEGF (4 eyes). The proportion of eyes with plus disease was significantly higher in the V group (50.0%) than in the non-V group (10.0%) (P = 0.035). V group included 3 of 22 eyes (13.6%) in which the interval between the last examination and the diagnosis of reactivation was <1 week and 3 of 5 eyes (60.0%) in which the interval was more than 1 week (P = 0.024). The two groups showed no significant differences in the other factors.

CONCLUSION

Approximately 8% of eyes developed RD about 10 weeks after anti-VEGF therapy for ROP. Eyes with history of plus disease should be carefully monitored at appropriate intervals after anti-VEGF therapy for ROP.

Time of vitreal surgery for active retinopathy of prematurity

Background. The anatomical and functional results of surgery for retinopathy of prematurity (ROP) are determined not only by the stage of the pathological process, but also depend on the timing of its implementation.The aim: to estimate the effectiveness of vitrectomy for severe active retinopathy of prematurity, depending on the timing of surgical treatment.Methods. Vitreoretinal surgery was performed in 138 children (198 eyes) with severe stages of ROP. All patients were divided into three groups depending on the timing of surgical treatment: group 1 – 42–48 weeks of postconceptual age (PCA), with the progression of ROP after laser coagulation of the retina (LCS), group 2 – 39–41 weeks of PCA, with the progression of ROP after LCS, group 3 – 36–39 weeks of PCA, without previous LCS. A 3-port transscleral 27-G vitrectomy was performed by all patients. At the postoperative period, the results of vitrectomy were estimated by the anatomical attachment of the retina. The follow-up period was 12 months. Results. In group 1, in 31 cases (73.8 %), the surgical intervention was completed with silicone tamponade. By the end of the follow-up period, anatomical retinal attachment was achieved in 17 eyes (40.5 %).In group 2, surgical intervention was completed with silicone tamponade in 29 eyes (42 %). By the end of the follow-up period, anatomical retinal attachment was achieved in 52 eyes (75 %).In group 3, surgical intervention was completed with silicone tamponade in 11 of 87 eyes (12.6 %). Anatomical retinal attachment was achieved in 80 eyes (92 %).Conclusion. Untimely vitrectomy (42–48 weeks of PCA) in cases of ROP progression after LCR led to a worse result. If progress of ROP after laser treatment happens, early vitrectomy (39–41 weeks of PCA) should be performed. Primary vitrectomy should be performed in case of the optimal timing of laser treatment has been missed (after 36 weeks of PCV).

Incidence and Factors of Postoperative Lens Opacity after Lens-Sparing Vitrectomy for Retinopathy of Prematurity

PURPOSE

To determine the incidence and factors associated with lens opacity after lens-sparing vitrectomy (LSV) for retinopathy of prematurity (ROP).

DESIGN

Retrospective, comparative case series.

PARTICIPANTS

Among the 141 eyes of 94 patients who underwent LSV for ROP between 2006 and 2019, 108 eyes of 71 patients with a minimum follow-up of 12 months after LSV were investigated.

METHODS

Data were collected from patients' charts, including gender, gestational age at birth, birth weight, stage of ROP, postmenstrual age (PMA) at LSV, surgical procedure, preoperative injection of anti-vascular endothelial growth factor (VEGF) agents, subsequent retinal surgeries, and lensectomy during follow-up.

MAIN OUTCOME MEASURES

Lens status at last visit, incidence and timing of lensectomy, and risk factors for lens opacity requiring lensectomy.

RESULTS

Stages of ROP at LSV were 4A, 4B, and 5 in 92 eyes, 13 eyes, and 3 eyes, respectively. The median PMA at LSV was 40.6 weeks. Thirty-two eyes received anti-VEGF therapy before LSV. Lens opacity was found in 17 eyes (15.7%), of which 10 eyes (9.3%) underwent lensectomy. The period between LSV and lensectomy ranged from 21 days to 131.9 months (median, 21.1 months). Eleven other eyes (10.2%) underwent lensectomy as part of a reoperation for worsening of ROP. A total of 80 eyes (74.1%) preserved clear lenses at the latest follow-up examination after surgery (median, 6.8 years; range, 1-14 years). The Kaplan-Meier estimate showed that the proportion of patients with phakia at 5 and 10 years was 92.4% and 89.0%, respectively. Multivariate Cox regression analysis revealed that eyes with the use of tamponade at LSV (P = 0.005; odds ratio [OR], 25.68; 95% confidence interval [CI], 4.187-157.5) and young PMA at LSV (P = 0.033; OR, 1.047; 95% CI, 1.012-1.099) were associated significantly with lens opacity requiring lensectomy. However, anti-VEGF therapy was not associated with lens opacity requiring lensectomy.

CONCLUSIONS

Nearly 10% of eyes required lensectomy because of lens opacity after LSV for ROP. The development of lens opacity requiring lensectomy seems to be associated with the use of tamponade and young PMA at LSV.

Retinal haemorrhage rates and resolution time of retinal haemorrhage in newborns after hypothermic treatment for hypoxic-ischemic encephalopathy

PURPOSE

The aim of this study was to evaluate retinal hemorrhages (RHs) in newborns after therapeutic hypothermia performed for hypoxic-ischemic encephalopathy (HIE).

METHODS

From 2014 January to October 2016, full-term newborns who were referred to us from the neonatal intensive care unit at our hospital for ophthalmological examination were evaluated retrospectively. Neonates diagnosed with HIE were examined with a RetCam Digital Retinal Camera (Massie Research Laboratories Inc., Pleasanton, CA) using a 130-degree or binocular indirect ophthalmoscope (Heine, Herrsching, Germany) imaging tool and were classified into three groups. Group 1 included patients without HIE, group 2 included patients with stage I HIE, and group 3 included patients with stage II or III HIE. The RH rates in cases of HIE were retrospectively reviewed.

RESULTS

A total of 148 eyes of 74 patients were included in the study. RH was detected in 36 eyes (24.3%); there were two eyes (3.7%), 14 eyes (20.6%), and 20 eyes (76.9%), in groups 1, 2, and 3, respectively. In group 3, RH was mostly seen in a widespread form. RHs involving the macula were resorbed later than haemorrhages in other locations.

CONCLUSION

RHs are frequent in neonates with HIE. RHs were seen significantly more frequently in stage II-III HIE. These haemorrhages may require treatment, especially when the macula is involved.