Platelet distribution width is a predictive marker for development of severe retinopathy of prematurity

The relationship between inflammatory markers and retinopathy of prematurity in extremely premature infants

PURPOSE

This study aimed to evaluate the relationships among blood parameters, clinical factors, and retinopathy of prematurity (ROP) in extremely premature (EP) infants.

METHODS

This retrospective study included 153 EP infants who were categorized into two groups based on the presence of inflammatory diseases such as necrotizing enterocolitis, neonatal sepsis, bronchopulmonary dysplasia, severe intraventricular hemorrhage, preeclampsia, and premature rupture of membranes. Complete blood count parameters, neutrophil-lymphocyte ratio (NLR), lymphocyte-monocyte ratio, platelet-lymphocyte ratio (PLR), systemic inflammatory index, and platelet mass index were recorded during the first week and first month after birth. The study analyzed the impact of parameters obtained through blood tests during the first week and first month on the development of ROP and the requirement for treatment.

RESULTS

In this study, 96 infants were diagnosed with inflammatory diseases. After multivariate regression analyses, the duration of mechanical ventilation (p = 0.010) was found to be the only factor that led to ROP development. Moreover, lower gestational age (GA) (p = 0.006), higher NLR (p = 0.026), and lower PLR (p = 0.019) were observed in infants requiring treatment compared to infants with spontaneous resolution of ROP in this group. 57 infants did not have inflammatory diseases. Although the duration of mechanical ventilation (p = 0.041) and low levels of platelets (PLT) (p = 0.046) measured in the first month postnatally were significantly found to be associated with ROP developement, no parameter affecting the required treatment could be determined.

CONCLUSION

EP infants with longer mechanical ventilation durations and lower PLT counts are vulnerable to ROP development. GA, PLR, and NLR are predictive factors for treatment.

Predictive factors of early reactivation after ıntravitreal ranibizumab in agressive retinopathy of prematurity

OBJECTIVE

Anti-VEGF agents are used in the treatment of aggressive retinopathy of prematurity (A-ROP), which is a rapidly progressive form of retinopathy of prematurity (ROP). This study aimed to evaluate risk factors for the early reactivation after anti-VEGF therapy with intravitreal ranibizumab (IVR) injection.

METHODS

Consecutive cases of A-ROP were included in this retrospective study. Intravitreal ranibizumab (0.25mg, Lucentis, Novartis AG) was injected in all A-ROP cases as initial therapy. Probable risk factors were reviewed. A reactivation in 4 weeks or less was defined as "early", and greater than 4 weeks was defined as "late". Since reactivations were observed in Zone II in all cases, laser photocoagulation (LP) was performed as rescue therapy.

RESULTS

The study consisted of 16 patients with A-ROP, all of whom experienced reactivation. In 6 cases,reactivation was seen early (Group-E), and in 10 cases, reactivation was late (Group-L). The mean gestational age of Group-E and Group-L were 26.60 (±0.89) and 26.73 (±2.10) weeks respectively (P=0.9), and mean birth weights were 918 (±282) and 898 (±0188) grams respectively (P=0.8). Zone I ROP was seen at a higher rate in Group-E (83.3%) than Group-L (30%) (P=0.009). Total O2 treatment duration in Group-E was statistically significantly longer than Group-L (P=0.03). The mean value of platelet distribution width (PDW) in Group-E was statistically significantly higher (P=0.002).

CONCLUSIONS

In patients with A-ROP, extended duration of O2 therapy and high values of PDW might be factors predictive of early reactivation after intravitreal ranibizumab injection.

Platelet Counts and Risk of Severe Retinopathy of Prematurity: A Bayesian Model-Averaged Meta-Analysis

BACKGROUND

We aimed to conduct a systematic review and Bayesian model-averaged meta-analysis (BMA) on the association between platelet counts and severe retinopathy of prematurity (ROP).

METHODS

We searched for studies reporting on platelet counts (continuous variable) or thrombocytopenia (categorical variable) and severe ROP or aggressive posterior ROP (APROP). The timing of platelet counts was divided into Phase 1 (<2 weeks) and Phase 2 (around ROP treatment). BMA was used to calculate Bayes factors (BFs). The BF10 is the ratio of the probability of the data under the alternative hypothesis (H1) over the probability of the data under the null hypothesis (H0).

RESULTS

We included 21 studies. BMA showed an association between low platelet counts and severe ROP. The evidence was strong (BF10 = 13.5, 7 studies) for phase 1 and very strong (BF10 = 51.0, 9 studies) for phase 2. Thrombocytopenia (<100 × 109/L) in phase 2 was associated with severe ROP (BF10 = 28.2, 4 studies). Following adjustment for publication bias, only the association of severe ROP with thrombocytopenia remained with moderate evidence in favor of H1 (BF10 = 4.30).

CONCLUSIONS

Thrombocytopenia is associated with severe ROP. However, the evidence for this association was tempered when results were adjusted for publication bias.

Association of platelet deficiency with severe retinopathy of prematurity: a review

AIM

The aim of this review was to compile existing evidence on the role of platelets in the development of severe retinopathy of prematurity (ROP), highlight the strengths and weaknesses of the available studies and critically discuss the reported data.

METHODS

A comprehensive literature search was conducted on PubMed from January 2000 to January 2022, and the reference lists of the included studies were screened manually.

RESULTS

There were 19 primary studies that fulfilled the eligibility criteria. Experimental research indicated lower platelet count in mice oxygen-induced retinopathy model compared with normoxia controls, while platelet transfusions suppressed neovascularisation. The latter finding was not consistently confirmed in clinical research, where a low platelet count, an increased number of thrombopenic episodes and of platelet transfusions have all been implicated in the development of ROP requiring treatment, either type I or aggressive posterior or both. However, existing studies exhibit significant clinical heterogeneity and present methodological limitations that imperil their reliability and validity.

CONCLUSION

Platelet deficiency has been associated with severe ROP. However, critical thresholds of platelet parameters are still unrecognised. Future research is required to determine whether platelet parameters can be predictive biomarkers for ROP requiring treatment and at what thresholds.

Comparison of Mean Platelet Counts in Preterm Infants with and without Retinopathy of Prematurity

Platelets are a primary source of pro- and anti-angiogenic cytokines. However, the evidence of their role in retinopathy of prematurity (ROP) is controversial. This retrospective study aimed to compare mean weekly platelet counts between infants with and without ROP over the first 6 weeks of life. A total of 93 infants matched by gestational age and birth weight were recruited (31 with ROP, 62 without ROP). Weekly mean platelet counts and other related risk factors were documented. The repeated measure analysis of variance (ANOVA) and the repeated measure analysis of covariance (ANCOVA) were used to compare mean platelet counts over time between the two groups, with and without adjusting for confounders. We found significant differences in the weekly mean platelet counts of infants with and without ROP over the first 6 weeks of life (p = 0.002). These differences disappeared after adjusting for covariates (p = 0.489). Lower mean platelet counts in ROP infants are not directly related to ROP, but rather to the presence of other risk factors for ROP, such as culture-proven sepsis, blood transfusion and bronchopulmonary dysplasia.