Fluorescein Angiographic Characteristics of Macular Edema During Infancy

Severity of cystoid macular oedema in preterm infants observed using hand-held spectral domain optical coherence tomography improves weekly with postmenstrual age

OBJECTIVE

To investigate the relationship between cystoid macular oedema (CMO) measured in preterm infants using hand-held spectral domain optical coherence tomography (HH SD-OCT), with gestational age at birth (GA), birthweight (BW), diagnosis of retinopathy of prematurity (ROP) and the presence or absence of the external limiting membrane (ELM).

METHODS

We conducted a prospective mixed cross-sectional/longitudinal observational study of 112 participants (23 to 36 weeks GA; n = 25 with, and n = 87 without, CMO). Retinal images were acquired using 344 HH SD-OCT (n = 66 with and n = 278 without, CMO) between 31 to 44 weeks postmenstrual age (PMA). CMO type ('fovea' and 'dome') was measured using thickness, width, area and peak.

RESULTS

CMO was observed in 22.9% of preterm infants, and 19.2% of images. The mean values for  thickness, width, area and peak of 'dome' CMO were 128.47 µm (SD +/- 34.23), 3624.45 µm (SD +/- 1323.03), 0.49 mm2 (SD +/- 0.28) and 279.81 µm (SD +/- 13.57) respectively. The mean values for  thickness, width, area and peak of 'fovea' CMO were 64.37 µm (SD +/- 17.11), 2226.28 µm (SD +/- 1123.82), 0.16 mm2 (SD +/- 0.11) and 95.03 µm (SD +/- 26.99) respectively. Thickness, area width and peak were significantly greater for 'dome CMO compared with 'fovea' CMO (P < 0.0001 for thickness, area and peak; P < 0.01 for width). Area and width significantly decreased with PMA for 'dome' and 'fovea' CMO (p = 0.0028; p < 0.001 respectively). No association was found between the presence of ROP and the detection of CMO or detection of CMO with absence of ELM.

CONCLUSIONS

HH -OCT in preterm infants demonstrates that the severity of CMO appearance improves each week for both fovea and dome CMO.

Preterm infant retinal OCT markers of perinatal health and retinopathy of prematurity

The increasing survival of preterm infants has led to the importance of improving long-term outcomes associated with preterm birth. Antenatal and perinatal insults not only impact mortality, but also long-term disability. While in the intensive care nursery, preterm infants are also exposed to various stressors that lead to long-term cognitive deficits. It is therefore critical to identify early, low-stress, non-invasive biomarkers for preterm infant health. Optical coherence tomography (OCT) is a powerful imaging modality that has recently been adapted to the infant population and provides noninvasive, high-resolution, cross-sectional imaging of the infant eye at the bedside with low stress relative to conventional examination. In this review we delve into discussing the associations between preterm systemic health factors and OCT-based retinal findings and their potential contribution to the development of non-invasive biomarkers for infant health and for retinopathy of prematurity (ROP).

Insights into the developing fovea revealed by imaging

Early development of the fovea has been documented by histological studies over the past few decades. However, structural distortion due to sample processing and the paucity of high-quality post-mortem tissue has limited the effectiveness of this approach. With the continuous progress in high-resolution non-invasive imaging technology, most notably optical coherence tomography (OCT) and OCT angiography (OCT-A), in vivo visualization of the developing retina has become possible. Combining the information from histologic studies with this novel imaging information has provided a more complete and accurate picture of retinal development, and in particular the developing fovea. Advances in neonatal care have increased the survival rate of extremely premature infants. However, with enhanced survival there has been an attendant increase in retinal developmental complications. Several key abnormalities, including a thickening of the inner retina at the foveal center, a shallower foveal pit, a smaller foveal avascular zone, and delayed development of the photoreceptors have been described in preterm infants when compared to full-term infants. Notably these abnormalities, which are consistent with a partial arrest of foveal development, appear to persist into later childhood and adulthood in these eyes of individuals born prematurely. Understanding normal foveal development is vital to interpreting these pathologic findings associated with prematurity. In this review, we first discuss the various advanced imaging technologies that have been adapted for imaging the infant eye. We then review the key events and steps in the development of the normal structure of the fovea and contrast structural features in normal and preterm retina from infancy to childhood. Finally, we discuss the development of the perifoveal retinal microvasculature and highlight future opportunities to expand our understanding of the developing fovea.

Trends in Neonatal Ophthalmic Screening Methods

Neonatal ophthalmic screening should lead to early diagnosis of ocular abnormalities to reduce long-term visual impairment in selected diseases. If a treatable pathology is diagnosed within a few days after the birth, adequate therapy may be indicated to facilitate the best possible conditions for further development of visual functions. Traditional neonatal ophthalmic screening uses the red reflex test (RRT). It tests the transmittance of the light through optical media towards the retina and the general disposition of the central part of the retina. However, RRT has weaknesses, especially in posterior segment affections. Wide-field digital imaging techniques have shown promising results in detecting anterior and posterior segment pathologies. Particular attention should be paid to telemedicine and artificial intelligence. These methods can improve the specificity and sensitivity of neonatal eye screening. Both are already highly advanced in diagnosing and monitoring of retinopathy of prematurity.

Analysis of optical coherence tomography angiographic findings of prematurely born children and its relationship with macular edema of prematurity

PURPOSE

To compare foveal avascular zone (FAZ) area, foveal vascular density (VD), and foveal thickness in pre- and full-term children and to evaluate their relationship with cystoid macular edema (CME) in the prematurity period using spectral domain optical coherence tomography angiography (SD-OCTA).

METHODS

OCTA imaging was performed at 4-6 years of age in 90 eyes of 45 prematurely born children and 50 eyes of 25 term children. Subjects were divided into three groups: prematurely born with CME (group 1); prematurely born without CME (group 2); healthy, term children (group 3). Imaging results in the three groups were compared.

RESULTS

FAZ area was significantly larger in group 3 than in groups 1 and 2 (P < 0.001 [ANOVA]). FAZ area was found to be correlated with birth weight (r = 0.511; P < 0.001) and gestational age (r = 0.532; P < 0.001). No significant relationship was found between history of CME and FAZ area.

CONCLUSIONS

In our study cohort, FAZ area was smaller in prematurely born children and was correlated with older gestational age and higher birth weight. CME in the neonatal period did not seem to affect retinal microvascular development in premature infants.

Regression of Cystoid Macular Edema Three Weeks After Laser for Retinopathy of Prematurity

Cystoid macular edema (CME) has been reported in the neonatal period associated with preterm birth; however, its pathogenesis remains unclear and is likely multifactorial. The authors report the case of a preterm infant imaged using optical coherence tomography (OCT), which revealed severe CME that regressed after laser treatment. Because laser for retinopathy of prematurity aims to reduce vascular endothelial growth factor (VEGF) levels, this case considers the possibility of VEGF-mediated CME pathogenesis. Further, the authors provide additional evidence of the value of OCT for noninvasive visualization of the preterm retina; the modality provides an effective way to evaluate and monitor progression of CME. [Ophthalmic Surg Lasers Imaging Retina. 2020;51:472-475.].

Experimental Evidence Behind Clinical Trial Outcomes in Retinopathy of Prematurity

Treatment of severe retinopathy of prematurity (ROP) has evolved over the last decade. This article reviews recent clinical trials and experimental evidence that supports clinical outcomes and observations, including the efficacy of anti-vascular endothelial growth factor (VEGF) agents in reducing the vascular activity of severe ROP, and the mechanisms behind recurrent stage 3 ROP and plus disease in some infants treated with anti-VEGF agents. Also discussed will be current imaging modalities that link experimental models of ROP with longitudinal human studies and which provide exciting future opportunities to enhance the understanding of pathophysiology of ROP and improve treatments. [Ophthalmic Surg Lasers Imaging Retina. 2019;50:228-234.].