First, let’s take a step back, and look at how the most common type of retinal detachments (rhegmatogenous retinal detachment) form.
These retinal detachments develop when the retina develops a tear, or a hole. And the tear or hole develops if the vitreous gel next to the retina is abnormally stuck on the retina and exerts a pulling force (traction) on the retina. This can happen naturally when the vitreous gel partially liquefies with age.
The only (theoretical) connection with LASIK is that during LASIK, there is pressure exerted on the eyeball for short periods of time, of the order of 2-3 minutes at most. This might cause deformation of the eye with respect to the vitreous gel and increase the risk of retinal problems.
However, studies have shown that the risk of retinal detachment after LASIK is very low, of the order of 0.06%-0.08% ie 6-8 per 10,000 cases done. These studies* looked at cases within the first 2 years of LASIK.
*(Arevalo JF, Ramirez E, Suarez E, et al. Incidence of vitreo-retinal pathologic conditions 24 months after laser-assisted in situ keratomileusis (LASIK). Ophthalmology 2000; 107:258–262.
Arevalo JF, Ramirez E, Suarez E, et al. Retinal detachment in myopic eyes after laser in situ keratomileusis. J Refract Surg 2002; 18:708–714.)
Now what about the long term, perhaps greater than 2 years after LASIK?
As mentioned, the mechanical effects of LASIK involve only transient pressure exerted on the eye. You could think of it as a short period of rubbing the eye hard. It is hard to think that such an action could have any long term effects on the eye. Certainly, one study* looking at cases 10 years after LASIK found that the rate of retinal detachment was 0.05%, or 5 in 10,000, which is essentially the same as the short term rates.
*(Rhegmatogenous retinal detachment after LASIK for myopia of up to -10 diopters: 10 years of follow-up.
Arevalo JF, Lasave AF, Torres F, Suarez E.
Graefes Arch Clin Exp Ophthalmol. 2012 Jul;250(7):963-70. )
And when one study compared the characteristics of retinal detachments between myopic eyes without LASIK, and others that had prior LASIK up to 5 years previously, there were no differences*.
*(Characteristics of rhegmatogenous retinal detachment after refractive surgery: comparison with myopic eyes with retinal detachment.
Kang HM, Lee CS, Park HJ, Lee KH, Byeon SH, Koh HJ, Lee SC.
Am J Ophthalmol. 2014 Mar;157(3):666-72)
The authors concluded that ‘Myopia is a well-known risk factor for rhegmatogenous RD and may contribute more to the development of RD in myopic patients after refractive surgery, rather than refractive surgery itself.’
To sum up, current evidence shows a very low risk of retina detachment after LASIK, that is similar to that seen in people who have not undergone LASIK.
Furthermore, long term studies show no difference compared with short term studies, suggesting that LASIK does not increase the risk of retina detachment in the long term.
Before undergoing LASIK, all patients have a thorough eye check including a full retina check through dilated pupils, to look for any retinal breaks that might be present. If present, these would be treated with laser to seal the break before the LASIK was performed.
In fact, by undergoing such a thorough check, it is possible that some patients have their risk of developing retinal detachment reduced because any breaks that are detected will be sealed with laser treatment before the retina actually detaches.