Avascular Peripheral Retina in Infants.

Avascular peripheral retina in an infant is a common characteristic of numerous pediatric retinal vascular disorders and often presents a diagnostic challenge to the clinician. In this review, key features of each disease in the differential diagnosis, from retinopathy of prematurity, familial exudative vitreoretinopathy, Coats disease, incontinentia pigmenti, Norrie disease, and persistent fetal vasculature, to other rare hematologic conditions and telomere disorders, will be discussed by expert ophthalmologists in the field.

Evaluation of macular microvascular structure with optical coherence tomography angiography in children with history of treatment for retinopathy of prematurity.

PURPOSE: To compare macula vascular parameters in optical coherence tomography angiography (OCTA) of children with history of retinopathy of prematurity (ROP) who were treated with laser photocoagulation (LPC) or intravitreal Bevacizumab therapy. METHODS: Forty eyes of 28 ROP children treated with LPC and 36 eyes of 22 ROP children treated with intravitreal Bevacizumab and 40 eyes of 40 age-gender matched term children were included the study. Capillary plexus densities in macula, FAZ parameters, outer retina and choriocapillaris flow rates, and central foveal thickness were measured. RESULTS: Foveal superficial and deep capillary plexus densities were found significantly higher in LPC and intravitreal Bevacizumab injection (IBI) groups compared to control group. FAZ area was found significantly lower in LPC and IBI groups compared to control group (p < 0.001). Higher foveal superficial capillary plexus density, higher central foveal thickness, and lower FAZ area were found to be associated with poorer visual acuity in correlation analysis (p < 0.05). In IBI group, earlier anti-VEGF therapy was found to be associated with lower foveal superficial capillary plexus density. CONCLUSION: Microvascular characteristics such as FAZ area and capillary plexus densities of macula are deteriorated in ROP. There is no significant difference between the treatment alternatives of ROP in terms of macular microvascular parameters.

Potential role of Müller cells in the pathogenesis of macropsia associated with epiretinal membrane: a hypothesis revisited.

Pathophysiological explanations for metamorphopsia associated with retinal pathologies generally focus on photoreceptor organization disruption. However, the retinal microarchitecture is complicated, and we hypothesize that other retinal cells may also be involved. Metamorphopsia has been widely studied in eyes with epiretinal membranes and we revisit the idea that Müller cell displacement causes retinal macropsia. A PubMed query and related article search for the macula ultrastructure under normal and pathological conditions revealed an enormous amount of information, particularly ultrahigh definition optical coherence tomography and other retinal imaging modality studies. Findings of these imaging studies support our hypothesis that Müller cells, and not cone photoreceptors, are primarily responsible for macropsia in eyes with epiretinal membranes. More specifically, we conclude that displacement of Müller cell endfeet, and not photoreceptor cones, is a more likely the explanation for retinal macropsia associated with epiretinal membranes.

Diode laser photocoagulation posterior to the ridge in severe stage 3+ threshold retinopathy of prematurity.

PURPOSE: To evaluate the results of diode laser photocoagulation (DLP) of the retina posterior to the ridge in eyes with severe Zone II, Stage 3+ threshold retinopathy of prematurity (ROP). METHOD: DLP was applied posterior to the fibrovascular ridge for advanced Zone II, Stage 3+ threshold ROP patients, either as the primary treatment combined with DLP of the avascular retina (group 1), or as a secondary treatment in eyes that had previously undergone DLP of the avascular retina (group 2). Statistical analysis was performed using SPSS software trail version 16.0. Values are presented as mean ± SD. RESULTS: A total of 50 eyes of 29 premature infants were treated (14 [48%] male, 15 [52%] female). The mean gestational age was 29.5 ± 2.2 weeks (range: 26-34 weeks). The mean birth weight was 1259 0.72 ± 409.15 g (range: 500-2050 g). The mean gestational age for DLP of the avascular region anterior to the ridge and DLP posterior to the ridge was 37 ± 3 weeks and 38 ± 3 weeks, respectively. The mean follow-up was 26 ± 5 weeks (18-38 weeks). In 48 eyes, the tractional fibrovascular ridge had regressed. Transient retinal hemorrhage was the most common complication. Three eyes exhibited optic-disc dragging; two eyes progressed to Stage 4a ROP; two eyes presented with macular traction, without any detachment; and one eye developed a vitreous hemorrhage, which resolved spontaneously. There were no statistically significant differences between complicated and uncomplicated eyes regarding gestational age, birth weight and applied laser spot numbers (p > 0.05 for all, Mann-Whitney U test). CONCLUSION: DLP, posterior to the ridge as an additive treatment in the management of severe Zone II, Stage 3+ threshold ROP patients, is safe and effective; this approach could be used as either the primary treatment, or as the follow-up to failed laser treatment of the avascular retina to halt the progression of the disease.

Peeling of internal limiting membrane during vitrectomy for complicated retinal detachment prevents epimacular membrane formation.

BACKGROUND: To investigate the clinical benefit of internal limiting membrane (ILM) peeling at the macula for the prevention of epimacular membrane formation following vitreous surgery using silicone oil for the treatment of complicated retinal detachment. METHODS: This was a non-randomized, retrospective, interventional study of a case series. Patient charts were reviewed retrospectively for 20 consecutively recruited patients who underwent successful primary vitrectomy with ILM peeling at the macula using silicone oil (group 1) and 22 consecutively recruited patients who underwent successful primary vitrectomy using silicone oil without ILM peeling at the macula for complicated rhegmatogenous retinal detachment (group 2). The main outcome measures were distant visual acuity and epimacular membrane formation. The data were analyzed and compared using Fisher's Exact test, Pearson Chi-square test, independent t-test, Mann-Whitney U-test, and a repeated ANOVA. RESULTS: The mean age of patients was 52.7 +/- 12.6 years in group 1 and 53.2 +/- 13.3 years in group 2 (p = 0.89). The mean follow-up time was 24.6 +/- 7.6 weeks in group 1 and 34.1 +/- 12.6 weeks in group 2 (p = 0.01). Preoperatively, ten eyes in group 1 and 10 eyes in group 2 were pseudophakic; the macula was detached in all cases. Silicone oil had been removed from all eyes of both groups at least 3 months before the final examination. There were no significant differences between the two groups with regard to sex (p = 0.44), mean duration of retinal detachment (p = 0.12), mean preoperative visual acuity (logMAR), mean number of retinal breaks (p = 0.43), and grade of proliferative vitreoretinopathy (p = 0.35). The final visual acuity (logMAR) was 0.60 +/- 0.30 in group 1 and 0.72 +/- 0.35 in group 2 (p = 0.49). Four eyes in group 1 and two eyes in group 2 underwent cataract surgery during silicone oil removal. Epimacular membrane formation was observed in two eyes before silicone oil removal and in four eyes within 8 weeks after silicone oil removal in group 2. No epimacular membrane formation was seen in group 1 (p = 0.02). CONCLUSION: ILM peeling at the macula during vitreous surgery with silicone oil for the treatment of complicated retinal detachment may prevent epimacular membrane formation without negatively affecting distant visual acuity.

Interleukin-8, nitric oxide and glutathione status in proliferative vitreoretinopathy and proliferative diabetic retinopathy.

PURPOSE: To evaluate interleukin-8 (IL-8), nitric oxide (NO) and glutathione (GSH) profiles in vitreous humor and blood samples in patients with proliferative diabetic retinopathy (PDR) and in patients with proliferative vitreoretinopathy (PVR) and to compare the levels with those of controls. PATIENTS AND METHODS: NO concentrations were determined by using the Greiss reaction in plasma and vitreous humor samples. GSH levels were determined in both blood and vitreous humor samples, using DTNB, a disulfide chromogen. Vitreous IL-8 were assayed by ELISA. Twenty-three patients with PDR, 18 patients with PVR and 21 cadavers as the control group were included in the study. RESULTS: Plasma and vitreous NO levels were found to be 25.6 +/- 2.1 and 36.9 +/- 3.0 micromol/l in patients with PDR, 27.0 +/- 4.7 and 34.3 +/- 2.9 micromol/l in patients with PVR and 17.4 +/- 2.7 and 15.9 +/- 1.4 micromol/l in controls, respectively. Vitreous humor and plasma NO levels did not show any statistically significant difference between PDR and PVR groups. However, the values for vitreous in both groups were significantly higher than those of controls (p < 0.0001). Although IL-8 levels in vitreous samples of patients with PDR were not significantly different (79.6 +/- 9.7 pg/ml) from those of patients with PVR (42.2 +/- 7.3 pg/ml) (p = 0.06), the levels in both groups were significantly higher than those of controls (19.0 +/- 3.9 pg/ml) (p < 0.0001 and p < 0.05, respectively). Blood and vitreous GSH levels were found to be 5.3 +/- 0.4 micromol/g. Hb and 0.58 +/- 0.16 micromol/l in patients with PDR and 8.4 +/- 0.5 micromol/g. Hb and 15.7 +/- 2.2 micromol/l in patients with PVR and 12.0 +/- 1.1 micromol/g. Hb and 0.26 +/- 0.03 mmol/l in controls, respectively. Vitreous and blood GSH levels were significantly lower in patients with PDR compared to those with PVR (p < 0.0001 for both). CONCLUSION: Elevated levels of vitreous and plasma NO and vitreous IL-8 in PDR and PVR implicate a role for these parameters in the proliferation in these ocular disorders. GSH concentrations both in vitreous and blood samples of the PVR and PDR patients were much less than those observed in the control group. Lower GSH concentrations detected in PDR in comparison with those in PVR in vitreous humor and to a lesser degree in blood may play an important role in pathogenesis of new retinal vessel formation in patients with PDR. This also suggests that oxidative stress may be involved in the pathogenesis of PVR and particularly that of PDR.