Use of Optical Coherence Tomography and Electroretinography to Evaluate Retinal Pathology in a Mouse Model of Autoimmune Uveitis

Purpose: Epiretinal membrane (ERM) is a common retinal finding for patients older than 50 years. Disorganization of the retinal inner layers (DRIL) has emerged as a novel predictor of poor visual acuity (VA) in eyes with inner retinal pathology. The aim of our study is to correlate preoperative DRIL with visual outcomes after ERM surgery. Methods: Medical records and optical coherence tomography (OCT) images of 81 pseudophakic patients who underwent treatment of idiopathic ERM were reviewed. Preoperative DRIL on OCT was correlated with VA at baseline and at 3 and 6 months after ERM surgery. DRIL was defined as the loss of distinction between the ganglion cell–inner plexiform layer complex, inner nuclear layer, and outer plexiform layer. DRIL severity was based on its extent within the central 2-mm region of a transfoveal B-scan (absent/mild: <one-third, severe: >one-third horizontal width). Results: Review of preoperative OCT showed severe DRIL in 41% and absent/mild DRIL in 59%. Severe DRIL was associated with worse baseline VA ( P < .001). Preoperative VA and DRIL status at baseline were both predictors of postoperative VA at follow-up time points ( P < .001). Severe DRIL was associated with significantly less improvement in VA at 6 months (–0.23 logMAR for absent/mild vs –0.14 for severe DRIL). Conclusions: Presence of severe preoperative DRIL correlates with worse baseline VA in patients with ERM and reduced VA improvement at 6 months. DRIL can be a strong predictor of long-term poor visual outcomes in ERM surgery.

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Time-serial Assessment of Drug Combination Interventions in a Mouse Model of Colorectal Carcinogenesis Using Optical Coherence Tomography

Cancer Growth and Metastasis ◽

10.4137/cgm.s21216 ◽

2015 ◽

Vol 8s1 ◽

pp. CGM.S21216 ◽

Cited By ~ 1

Author(s):

Susan LeGendre-McGhee ◽

Photini S. Rice ◽

R. Andrew Wall ◽

Kyle J. Sprute ◽

Ramireddy Bommireddy ◽

...

Keyword(s):

Colorectal Cancer ◽

Growth Rate ◽

Optical Coherence Tomography ◽

Mouse Model ◽

Tumor Burden ◽

Colorectal Carcinogenesis ◽

Optical Coherence ◽

Ki 67 ◽

Tumor Number ◽

Cox 2

Optical coherence tomography (OCT) is a high-resolution, nondestructive imaging modality that enables time-serial assessment of adenoma development in the mouse model of colorectal cancer. In this study, OCT was utilized to evaluate the effectiveness of interventions with the experimental antitumor agent α-difluoromethylornithine (DFMO) and a nonsteroidal anti-inflammatory drug sulindac during early [chemoprevention (CP)] and late stages [chemotherapy (CT)] of colon tumorigenesis. Biological endpoints for drug interventions included OCT-generated tumor number and tumor burden. Immunochistochemistry was used to evaluate biochemical endpoints [Ki-67, cleaved caspase-3, cyclooxygenase (COX)-2, β-catenin]. K-Ras codon 12 mutations were studied with polymerase chain reaction-based technique. We demonstrated that OCT imaging significantly correlated with histological analysis of both tumor number and tumor burden for all experimental groups ( P < 0.0001), but allows more accurate and full characterization of tumor number and burden growth rate because of its time-serial, nondestructive nature. DFMO alone or in combination with sulindac suppressed both the tumor number and tumor burden growth rate in the CP setting because of DFMO-mediated decrease in cell proliferation (Ki-67, P < 0.001) and K-RAS mutations frequency ( P = 0.04). In the CT setting, sulindac alone and DFMO/sulindac combination were effective in reducing tumor number, but not tumor burden growth rate. A decrease in COX-2 staining in DFMO/sulindac CT groups (COX-2, P < 0.01) confirmed the treatment effect. Use of nondestructive OCT enabled repeated, quantitative evaluation of tumor number and burden, allowing changes in these parameters to be measured during CP and as a result of CT. In conclusion, OCT is a robust minimally invasive method for monitoring colorectal cancer disease and effectiveness of therapies in mouse models.

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