ACRC/Macula 2023: Ocular Imaging Session

Saagar Pandit, MD
Wills Eye Hospital
Philadelphia, PA

The Saturday Ocular Imaging Session was exciting as always on the Saturday Macula 2023 update.

Dr. Llyod Clark discussed updates on the Notal Vision Home optical coherence tomography (OCT). This is an important topic given its potential use in monitoring and detecting various retinal pathology, such as conversion of patients from “dry” to “wet” age-related macular degeneration. Spectral domain images are taken in the comfort of one’s home, uploaded to an analyzer, and the presence or absence of intraretinal fluid, subretinal fluid, and other findings are automatically detected by an algorithm. Manual thresholds are set to notify a doctor if a patient may require treatment or not. Dr. Clark presented data from an at-home imaging study which demonstrated that 91% of subjects (264/290) were able to successfully perform self-imaging with a high degree of correlation of presence/absence of SRF and presence/absence of IRF between an independent in-office OCT expert grader. However, it is important to note that patients with VA of 20/320 or worse did not reliably self-image, one of the limitations of this modality. In summary, early evidence suggests that Notal Vision Home OCT may be able to: 1) reliably produce high quality patient self-images 2) automatically detect and quantify fluid on OCTs 3) demonstrate how physicians and artificial intelligence may be able to work together to provide better patient care.

Dr Liederman’s talk entitled “AI – how will it change our practice in the next 5 years” began by reviewing evidence on the utility of artificial intelligence in diagnosing “referable” diabetic retinopathy: at least moderate non-proliferative diabetic retinopathy. He then went to discuss how artificial intelligence can help us extract new information from retinal fundus photographs, such as age (using blood vessel attenuation as a surrogate), gender, smoking status, systolic blood pressure, and major adverse cardiac events. Dr. Liederman talked about his remarkable work in using AI to help with real-time data integration and feedback to assist in cataract surgery (e.g. rhexis creation), with a feedback mechanism incorporated in a modified commercially available microscope. Applying these same principles to vitreoretinal surgery, AI can help enhance visualization when performing delicate procedures such as epiretinal membrane peeling. When performing endolaser for panretinal photocoagulation, AI-assisted technology can essentially perform “grid” endolaser such that the surgeon moves the endolaser probe back and forth while an automatic mechanism activates the laser at the appropriate position. His work in this field is especially exciting and we look forward to seeing what will come next.

Dr. Adrienne Scott updated us on the importance of widefield and ultra widefield imaging in the diagnosis and management of retinal vascular disease, inherited retinal dystrophies, and others. She recommends that patients with retinal vascular disease, such as those with sickle cell retinopathy or moderate NPDR, undergo ultra widefield fluorescein angiography and fundus photography to better characterize the degree of retinopathy which may have been otherwise missed by the standard seven fields. She highlighted findings from the Protocol AA which demonstrated that ultra widefield fluorescein angiography better characterized patients who had predominantly peripheral lesions and more accurately assessed those that progress to more advanced forms of DR, regardless of baseline DRSS score. In addition, peripheral OCT can be used to monitor disease activity and treatment effect, as she highlighted in her case of toxoplasmosis retinochoroiditis.

Dr. Fawzi kicked off a discussion of these papers by showing a patient with what appeared to be mild NPDR in the standard seven fields. However, the ultra widefield fundus image revealed at least moderate to severe NPDR. Dr. Scott highlighted how she obtains baseline ultra widefield imaging on her diabetic patients. Dr. Llyod Clark said: “baseline ultra widefield angiography is critical to understand what is going on in the back of the eye. For diabetics, a baseline test is warranted.” Next, Dr. Fawzi presented a case of PCV that she had treated with anti-VEGF with good response. Dr. Fawzi directed a question to Dr. Llyod Clark, asking if he would apply home-monitoring OCT to patient’s in this scenario to determine if they could have PRN treatment. His concern with home OCT for these patients is that given recurrence of neovascularization in PCV can be devastating for vision, it is better to see them in the office and continue treat-and-extend regimens. Dr. Clark went on to say that for other diseases, such as neovasular AMD, perhaps we could use PRN treatment once we have stabilized a patient with anti-VEGF injections every 16 weeks. In this scenario, home OCT may inform the treating doctor when the patient needs to come back for a repeat injection. Dr. Clark mentioned that if we are able to decrease the number of injections by two per year per patient, over five years there may be a significant cost reduction to the healthcare system. This was a fascinating discussion.