Overview of the two forms
AMD is broadly classified into two types. Dry AMD is the more common form and is typically associated with gradual changes in the macula over time. Wet AMD is less common but more active, involving changes beneath the retina that can lead to more rapid visual disturbance.
Understanding the distinction between these forms is important in recognising changes in vision and determining how the condition is monitored and managed.
Dry AMD
Dry AMD develops as a result of gradual structural changes within the macula. These changes may include thinning of retinal tissue and the accumulation of small deposits beneath the retina.
In many cases, progression is slow. Early stages may not cause noticeable symptoms, and vision may remain relatively stable for some time. As the condition advances, individuals may experience increasing blurring of central vision, reduced clarity and difficulty with tasks that require fine detail.
Changes in contrast sensitivity and visual precision may also occur, particularly in low-light conditions.
This video discusses what dry AMD is, and why monitoring through routine examinations is important. Have your patients watch this video while they wait, or email this video to your patients after their appointment so they may share it with loved ones.Wet AMD
Wet AMD is characterised by the development of abnormal blood vessels beneath the macula. These vessels can leak fluid or blood, disrupting the normal structure of the retina.
This form is typically associated with more rapid changes in vision. Individuals may notice sudden distortion, such as straight lines appearing bent or wavy, as well as more noticeable blurring or areas of central visual disturbance.
Because these changes can occur quickly, prompt assessment is important.
What is Wet AMD? This video provides an overview of wet AMD and explains why monitoring through routine examinations is important. Have your patients watch this video in-office, or email this video to your patients after their appointment so they may share it with loved ones.Key structural differences
In dry AMD, the changes are primarily related to degeneration and gradual alteration of retinal tissue.
In wet AMD, the presence of abnormal blood vessels introduces an additional process that can disrupt the macula more actively, leading to fluid accumulation or bleeding beneath the retina.
These structural differences contribute to the variation in how the two forms present and progress.
Differences in progression
Dry AMD generally progresses slowly over time. Changes in vision may occur gradually and may not be immediately noticeable.
Wet AMD tends to progress more rapidly. Visual changes can develop over a shorter period and may be more noticeable in everyday activities.
Differences in symptom pattern
Symptoms of dry AMD often begin subtly, with mild blurring or difficulty with detailed tasks. These changes typically worsen gradually.
In wet AMD, symptoms may include more pronounced distortion, rapid blurring or sudden changes in central vision. These differences in symptom pattern are important in recognising when more urgent assessment may be needed.
Impact on central vision
Both forms primarily affect central vision. This can interfere with activities such as reading, recognising faces and focusing on fine detail.
Peripheral vision is usually preserved in both types, allowing for general awareness of surroundings even as central vision changes.
Functional impact on daily activities
As AMD progresses, individuals may experience increasing difficulty with tasks that rely on visual precision. Reading may require more effort, recognising faces may become more challenging and activities such as driving may be affected.
The rate at which these changes occur varies between dry and wet forms.
Why the distinction matters
Distinguishing between dry and wet AMD is important because the behaviour of the condition differs between the two forms. This influences how vision changes are interpreted and how the condition is monitored over time.
Recognising the pattern of progression can help guide appropriate assessment and care.
Monitoring for change
Individuals with AMD are often monitored for changes in central vision, particularly the development of distortion or rapid visual decline.
Noticing new or worsening symptoms is important, as it may indicate a change in the condition that requires reassessment.