Which of the following is NOT transported from the choroid into the retina through the RPE?

The choice indicating that lactic acid is NOT transported from the choroid into the retina through the retinal pigment epithelium (RPE) is based on the specific roles and functions of the RPE as well as the metabolic processes of the retina.

The RPE plays a crucial role in maintaining the health of the retinal photoreceptors, particularly by facilitating the transport of essential nutrients and metabolic byproducts. Glucose is actively transported from the choroid into the retina, as it is a vital energy source for retinal cells. Similarly, retinal, which is the aldehyde form of vitamin A, is also transported as it is crucial for phototransduction – the process by which light is converted into electrical signals in the photoreceptors.

Additionally, W-3 fatty acids are known to be important for retinal health and function and are also transported from the choroid to the retina. In contrast, lactic acid is a byproduct of anaerobic metabolism, particularly in conditions where glucose is metabolized for energy without sufficient oxygen, like during intense activity or under certain pathological conditions. Under normal circumstances, lactic acid is generally removed from the retina primarily through the bloodstream rather than being transported across the RPE.

This distinction highlights the