Faculty Bibliography

PURPOSE: To evaluate the changes of vascular endothelial growth factor (VEGF) plasma levels after intravitreal injections of aflibercept or ranibizumab in patients with exudative age-related macular degeneration (AMD). METHODS: Thirty-eight patients with exudative AMD were included in this randomised, prospective study. Nineteen patients were randomised to treatment with intravitreal aflibercept (2.0 mg) and 19 to intravitreal ranibizumab (0.5 mg). The concentration of VEGF was measured by ELISA just before the injection, after 7 days and 1 month. Twenty-two age- and sex-matched healthy patients without chorioretinal diseases served as control. RESULTS: The median baseline plasma VEGF concentration was 61.0 pg/ml in the control group, 43.0 pg/ml in the aflibercept group and 59.0 pg/ml in the ranibizumab group (p=0.127). Seven days after intravitreal injection of aflibercept plasma levels were significantly reduced to values below the minimum detectable dose (MDD) in 17 of 19 patients (89.5%) resulting in a median VEGF concentration of <9 pg/ml (p<0.001). The reduction persisted throughout 1 month with values below the MDD in 5 of 19 patients (26.3%) and a median measurement of 17.0 pg/ml (p<0.001). In patients treated with ranibizumab no significant effects could be observed with a baseline VEGF of 59.0 pg/ml, 54.0 pg/ml at 7 days (p=0.776) and 58.5 pg/ml at 4 weeks of follow-up (p=0.670). CONCLUSION: After intravitreal aflibercept injection, the systemic VEGF levels were significantly reduced throughout the observational period of 4 weeks. No significant systemic effects of intravitreal ranibizumab on plasma VEGF were observed.

BACKGROUND AND OBJECTIVE: To evaluate subfoveal choroidal thickness (CT) in healthy eyes using spectral-domain optical coherence tomography (SD-OCT) and provide correlations between age and axial length. PATIENTS AND METHODS: Enhanced depth SD-OCT imaging was performed with Cirrus (Carl Zeiss Meditec, Dublin, CA) and Spectralis (Heidelberg Engineering, Heidelberg, Germany) instruments. CT was measured from the outer limit of the retinal pigment epithelium to the inner surface of the sclera. RESULTS: The study enrolled 155 patients, with at least 20 in each decade between 22 and 89 years old. Mean axial length was 23.6 mm. Mean Heidelberg subfoveal CT was 286 microm. The correlation between Heidelberg and Zeiss subfoveal CT measurements was strong (r = .978) and significant (P < .001). Mean subfoveal CT was 7.7 microm thinner by Heidelberg versus Cirrus (P < .001). Multiple linear regression analysis revealed that age (P < .001), axial length (P = .001), and sex (P = .025) were significantly related to Heidelberg subfoveal CT. CONCLUSION: There is a strong negative correlation between CT and age (P <.001), with a 25 microm decrease in CT for each decade of life. Increasing axial length demonstrated a negative correlation with CT, decreasing 24.9 microm for each mm of axial length. Future studies of CT measurements can be performed on either instrument and must account for axial length, age, and sex to make appropriate conclusions.

BACKGROUND AND OBJECTIVE: To evaluate subfoveal choroidal thickness (CT) and the extent of outer retinal disruption in patients with macular telangiectasia type 2 (MacTel2) compared with healthy eyes. PATIENTS AND METHODS: In this prospective, observational, cohort study, 62 patients (62 eyes) with Mac-Tel2 and 130 healthy controls (130 eyes) underwent a complete ophthalmological examination, spectral-domain optical coherence tomography (SD-OCT) imaging, and axial length measurements. Patients in the study group also underwent color fundus photography, fundus autofluorescence, and fluorescein angiography. En face SD-OCT imaging was used to assess abnormalities involving the photoreceptor inner segment/outer segment/ellipsoid zone (IS/OS/EZ). RESULTS: After adjusting for age and axial length, the authors found that eyes with MacTel2 had a mean CT measurement that was greater than control eyes (P = .007). There was a negative correlation between the visual acuity and the area of IS/OS/EZ damage (P = .009), but no statistically significant correlation was seen between CT and the area of IS/OS/EZ damage. CONCLUSION: Eyes with MacTel2 were found to have thicker CT measurements than control eyes. While the extent of IS/OS/EZ disruption correlated with the loss of visual acuity, this damage did not correlate with CT measurements.