A client with diabetes mellitus develops an ulcer on the bottom of the foot. Which pathology is the primary contributing factor to the ability of the ulcer to heal?

A) Blockage of retinal capillaries causing ischemic damage of the central macular area:

Correct. Blurry central vision that worsens over time can be indicative of macular ischemia, often caused by blockage of retinal capillaries leading to ischemic damage of the central macular area. This condition can occur in diseases such as diabetic retinopathy or retinal vein occlusion.

B) Opaque spoke-like lines developing in the periphery of the lens to the center:

This description is more characteristic of cataracts, which cause visual disturbances such as glare or halos around lights rather than blurry central vision.

C) Tears in the retina that detach from the lining of the posterior eyeball:

Retinal tears and subsequent detachment can cause visual disturbances, but they typically present as sudden onset of floaters, flashes of light, and a curtain-like shadow over the visual field rather than blurry central vision.

D) An increase in intraocular pressure with loss of peripheral vision:

This description is indicative of glaucoma, which can lead to loss of peripheral vision (visual field defects) rather than blurry central vision. Glaucoma-related visual field loss usually begins peripherally and progresses inward, affecting central vision in later stages.

Chronic osteoarthritis (OA) is a degenerative joint disease characterized by the breakdown of joint cartilage and underlying bone changes. The pathophysiological process of OA involves various factors contributing to joint pain and inflammation. Here's why option C is the correct choice:

A) Inflammation results from deposition of crystals in the synovial space of joints producing irritation:

This statement is more characteristic of crystal-induced arthritis, such as gout or pseudogout, where crystals (e.g., urate or calcium pyrophosphate crystals) deposit in the joints and cause acute inflammation and irritation. While inflammation may occur in OA, it is primarily a result of mechanical stress and cartilage degradation rather than crystal deposition.

B) Inflammation is caused by immune complex and autoantibody deposition in connective tissue:

This statement is more characteristic of autoimmune diseases such as rheumatoid arthritis (RA), where immune complex deposition and autoantibody production lead to chronic inflammation and joint damage. In OA, inflammation is not primarily mediated by immune complex deposition or autoantibodies.

C) Joint inflammation occurs when chondrocyte injury destroys joint cartilage, producing osteophytes:

Correct. In osteoarthritis, joint inflammation occurs as a result of chondrocyte injury and cartilage breakdown. Over time, the degenerative changes in the joint lead to the formation of osteophytes (bone spurs) at the joint margins. These changes can irritate surrounding tissues, including the synovium, ligaments, and tendons, contributing to joint pain and inflammation.

D) Joint destruction happens due to an autoimmune inflammation involving IgG response to an antigen:

This statement is more characteristic of autoimmune arthritis, such as rheumatoid arthritis (RA), where autoantibodies (e.g., rheumatoid factor, anti-citrullinated protein antibodies) target joint tissues, leading to chronic inflammation and joint destruction. In OA, joint destruction primarily results from mechanical stress and wear-and-tear on the joint structures rather than autoimmune mechanisms.