Adaptive Optics for Ophthalmic Technologies

Adaptive optics (AO) is an optical technique that corrects the natural aberrations (optical
imperfections) of the eye. Since it was first described in 1997, it has been used
successfully to enhance the visualization of retinal tissue, in particular, the human
photoreceptor mosaic. Previous studies using AO in the human eye have contributed to
considerable advancements in our understanding of vision and ocular pathologies.

An AO system sends a pattern of light into the eye that balances the eye's inherent
imperfections. This leads to better imaging by providing better light focusing by the natural
lens of the eye. The AO system measures the light returning from the eye as is typical in
clinically accepted optical coherence tomography and scanning laser ophthalmoscope systems.

A schematic AO system consists of a light input, a deformable/adaptive mirror that modifies
the shape of the light entering and exiting the eye, and a detector system that captures and
analyzes the returning light from the eye.

The device used in this feasibility study has been tested to ensure that its light output is
within ANSI limits for safe ocular exposure and is capable of obtaining useful images of the
peripheral retina in normal subjects.

Diabetic retinopathy represents the most common cause of vision loss in working aged adults.
Vision loss is related to two manifestations of advanced diabetic retinopathy: proliferative
diabetic retinopathy (PDR) and diabetic macular edema (DME). PDR occurs when the vascular
perfusion of the retina is compromised and compensatory signals including expression of
vascular endothelial growth factor causes neovascularization on the surface of the retina.
These abnormal vessels cause vision loss by either bleeding into the vitreous or by
contracting leading to retinal detachment. DME occurs when vascular leakage results in
swelling of the macular tissue causing central vision loss. While DME affects the macula (the
area typically imaged using OCT), PDR is much more frequently found in the peripheral retina
which is not typically imaged by traditional OCT devices. In recently years, wide field
fluorescein angiography has allowed insights into the relationship between DME, PDR and the
status of retinal blood vessels within the macula and the retinal periphery. WF-AO-OCT has
the potential to provide similar or complementary structural detail of the retinal tissue and
vasculature within the macula and retinal periphery. The advantage of WF-AO-OCT is that it is
a non-contact, non-invasive imaging technology which is easier to use, faster and less
invasive compared to fluorescein angiography which entails intravenous injection of
fluorescein, requires a skilled ophthalmic photographer and takes 10-20 minutes to perform.
By imaging participants who have previously undergone wide field fluorescein angiography as
standard of care, the investigators will be able to compare the information obtained using
WF-AO-OCT and to determine its sensitivity in identifying specific vascular and morphological
findings associated with PDR and DME.

Inclusion Criteria for diabetic retinopathy participants:

- Diagnosis of diabetic retinopathy in one or both eyes

- Men and Women, aged 18 years or older

- Able to provide written informed consent

Inclusion Criteria for healthy control participants:

- No history of retinal disease in one or both eyes

- Men and Women, aged 18 years or older

- Able to provide written informed consent

Exclusion Criteria for both diabetic retinopathy and healthy control participants:

- Significant media opacity (e.g. cataract or vitreous hemorrhage) precluding clinical
imaging adequate for interpretation

- Unwilling or unable to provide legally effective written consent