Quantification of the therapeutic response of intraretinal, subretinal, and subpigment epithelial compartments in exudative AMD during anti-VEGF therapy.
OBJECTIVE
To analyze the functional and morphologic effects of different ranibizumab treatment regimens on retinal and subretinal as well as sub-RPE compartments in neovascular age-related macular degeneration (nAMD) using spectral-domain optical coherence tomography (SD-OCT) and manual segmentation software.


METHODS
Twenty-seven eyes of 27 patients with nAMD were examined over a 12-month period. Two treatment arms received either monthly or quarterly administered intravitreal ranibizumab. Intraretinal, subretinal, and sub-RPE volume equivalents were delineated using manual segmentation software over a defined series of B-scans obtained by SD-OCT. The mean area in pixels was calculated for each compartment at each time interval.


RESULTS
SD-OCT and manual segmentation allowed for exact identification of intraretinal, subretinal and sub-RPE compartments and their responses to different treatment regimens. The loading dose demonstrated a corresponding treatment effect on all anatomic parameters. In contrast to the sub-RPE compartment, intraretinal fluid accumulation and subretinal fluid accumulation (SRFA) demonstrated an immediate response to ranibizumab therapy. The overall plasticity of the morphologic response declined over time. In general, SRFA demonstrated greater sensitivity for therapeutic effects and was more frequently associated with recurrent disease.


CONCLUSIONS
An exact quantification of fluid in different anatomic compartments based on SD-OCT imaging, using appropriate segmentation software systems, may be useful to determine optimal treatment and retreatment parameters and explains the lack of correlation of best-corrected visual acuity and conventional OCT values.
Department of Ophthalmology, Medical University of Vienna, Vienna, Austria.
Isabelle
I
Golbaz
Christian
C
Ahlers
Geraldine
G
Stock
Christopher
C
Schütze
Sabine
S
Schriefl
Ferdinand
F
Schlanitz
Christian
C
Simader
Christian
C
Prünte
Ursula Margarethe
UM
Schmidt-Erfurth
D020533:Angiogenesis Inhibitors / Q000627:therapeutic use*; D000911:Antibodies, Monoclonal / Q000627:therapeutic use*; D061067:Antibodies, Monoclonal, Humanized; D020256:Choroidal Neovascularization / Q000175:diagnosis / Q000188:drug therapy* / Q000378:metabolism; D005122:Exudates and Transudates; D005500:Follow-Up Studies; D006801:Humans; D021621:Imaging, Three-Dimensional; D058449:Intravitreal Injections; D008875:Middle Aged; D000069579:Ranibizumab; D012160:Retina / Q000187:drug effects / Q000473:pathology*; D055213:Retinal Pigment Epithelium / Q000187:drug effects / Q000473:pathology*; D058471:Subretinal Fluid / Q000378:metabolism; D041623:Tomography, Optical Coherence; D042461:Vascular Endothelial Growth Factor A / Q000037:antagonists & inhibitors*; D014792:Visual Acuity / Q000502:physiology; D057135:Wet Macular Degeneration / Q000175:diagnosis / Q000188:drug therapy* / Q000378:metabolism
D020533:Angiogenesis Inhibitors; D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A; D000069579:Ranibizumab