I am delighted to hear your skin improved after microneedling!
>Can individuals with problem skin (acne, scarring, large pores etc) use the retin-a indefinitely? All
>year round? Or would retin-a need to be cycled: 2months on, 1 month off (similar to what you
>advised about hydroquinone)?
Retin A does not need to be cycled but it makes the skin more sensitive to UV so you either have to use a sunscreen or reduce or discontinue the application of Retin A in summer.
>Can I use the retin-a along the thin skin around the eye area: eyelid, undereye area? (I understand
>this product is acidic and will sting)
In principle you can, but I do not really recommend using Tretinoin on the sensitive skin around the eyes. Our Infadolan ointment that contains Retinyl acetate is more suitable in this area. Apply daily, just a little.
Initially, Tretinoin makes the skin dry. Wrinkles and lines are more visible on dry skin and that is why it may seem in some cases that Tretinoin worsened wrinkles - but it did not. This is most likely to be the impression around the eyes where the skin is naturally less oily than elsewhere due to very few glands in the area.
>Once I've applied retin-a, is it fine to use an oil (olive oil, coconut, almond oil) over my skin as a
>moisturiser? Or shall I wait until the morning to moisturise my face?
Vit. A is oil-soluble and you can use any kind of moisturizer on top of Retin A. Tretinoin (Retin A) dries out the skin (especially initially) and it is a very good idea to use a moisturizer and even heavy moisturizers such as oils to offset the drying effect.