Are retinal tears always accompanied by degeneration?

[Chengtiantian]

Hi Dr., without considering trauma, do retinal tears always occur after retinal degeneration?
Is there a relationship between the thickness of the retina and retinal detachment?
Is it safe to assume that without retinal degeneration, the thinner retina would not have torn due to progressive posterior detachment of the vitreous?

[John C Hagan III, MD, FACS, FAAO]

Retinal holes/tears have many causes. By far the most common is the vitreous tears during a posterior vitreous detachment.  There is not much correlation with retinal thickness. No it is not safe to assumen your last sentence.

[Chengtiantian]

Thank you for your reply. May I ask Dr., at what age or what diopter is myopic macular degeneration more likely to occur? I am 23M, -8.5D

[John C Hagan III, MD, FACS, FAAO]

Most ophthalmologists use -6 diopters or more, you do have high myopia. Like all degenerative diseases it becomes more common as we age.

[Chengtiantian]

Thank you for your reply.
I would like to ask for the last time, should the Axial Length of 24mm be considered as the baseline for AL for each adult? Are there cases where the AL is longer than 24mm but not myopic? Is it reasonable for me to understand the refraction to be: reflecting how much I deviate from the AL baseline?
I apologize for my rambling question.

[Chengtiantian]

I mean myopic refraction rather than refraction

[John C Hagan III, MD, FACS, FAAO]

The average axial length of the doesn't tell much as there is much variation. Think like saying what is the average height of a person. Too much variation. Each mm of AX amounts to about 1.5-3 D of refractive power.  The range of common AL is 22-24 mm  The relationship of AL to glasses prescription is more complicated and depends on AL, radius of curviature of the cornea and the refractive power of a human lens or an intraacular lens and how far a lens is from the cornea. High myopes see better with contact lens because closer to eye and larger image than glasses