High myopia

Patients with high myopia are at increased risk of retinal tears and detachment. A thorough, dilated retinal examination (including scleral depression, if indicated) should be performed on all patients with high myopia, and a referral to a retina specialist should be considered for patients with predisposing retinal pathology. One study of 4800 consecutive patients in a private refractive surgery practice found that 52 (1.1%) had posterior segment pathology that required intervention. Another study of 29,916 myopic and hyperopic eyes undergoing LASIK demonstrated that 1.5% of patients required preoperative treatment of retinal pathology.

• Brady J, O’Keefe M, Kilmartin D. Importance of fundoscopy in refractive surgery. J Cataract Refract Surg. 2007;33(9):1602–1607.

Retinal detachment

Patients with high myopia should be counseled that refractive surgery corrects only the refractive aspect of the myopia and not the natural history of the highly myopic eye with its known complications. Such patients remain at risk of retinal tears and detachment throughout their lives, despite refractive surgery.

Although no causal link has been established between retinal detachment and excimer laser refractive surgery, the potential adverse effects should be considered. The rapid increase and then decrease in IOP could theoretically stretch the vitreous base, and the acoustic shock waves from the laser could play a role in the development of a posterior vitreous detachment. Although the actual risk to eyes with high myopia or preexisting retinal pathology has not been determined through well-controlled, long-term studies, current data suggest that radial keratotomy, surface ablation, and LASIK do not appear to increase the incidence of retinal detachment. The occurrence of retinal detachment after LASIK ranges from 0.034% to 0.250%. In a series of 1554 eyes that underwent LASIK for myopia with a mean refractive error of –13.52 ± 3.38 D, retinal detachments developed in 4 eyes (0.25%) at 11.25 ± 8.53 months after the procedure. Three of the eyes had retinal flap tears, and 1 eye had an atrophic hole. There was no statistically significant difference in BCVA before and after conventional retinal reattachment surgery. A myopic shift did result from the scleral buckle, however.

In a study of 38,823 eyes with a mean myopia of –6.00 D, the frequency of rhegmatogenous retinal detachments at a mean of 16.3 months after LASIK was 0.8%. The eyes that developed retinal detachments had a mean preoperative myopia of –8.75 D. In a retrospective review, Blumenkranz reported that the frequency of retinal detachment after excimer laser treatment was similar to the frequency in the general population, averaging 0.034% over 2 years. It would be important for the LASIK surgeon to let the operating retinal surgeon know that LASIK has previously been performed on the patient, because of the potential for flap dehiscence during retinal detachment surgery, especially during corneal epithelial scraping.

Highly myopic eyes undergoing phakic IOL procedures are at risk of retinal detachment from the underlying high myopia, as well as from the intraocular surgery. A retinal detachment rate of 4.8% was reported in a study of phakic IOLs used to correct high myopia.

• Arevalo JF. Posterior segment complications after laser-assisted in situ keratomileusis. Curr Opin Ophthalmol. 2008;19(3):177–184.

• Arevalo JF, Ramirez E, Suarez E, Cortez R, Ramirez G, Yepez JB. Retinal detachment in myopic eyes after laser in situ keratomileusis. J Refract Surg. 2002;18(6):708–714.

• Blumenkranz MS. LASIK and retinal detachment: should we be concerned? [editorial]. Retina. 2000;5:578–581.

• Qin B, Huang L, Zeng J, Hu J. Retinal detachment after laser in situ keratomileusis in myopic eyes. Am J Ophthalmol. 2007;144(6):921–923.

• Sakurai E, Okuda M, Nozaki M, Ogura Y. Late-onset laser in situ keratomileusis (LASIK) flap dehiscence during retinal detachment surgery. Am J Ophthalmol. 2002;134(2):265–266.

Previous retinal detachment surgery

Patients who have had prior scleral buckle surgery or vitrectomy may seek refractive surgery because of resultant myopia. Prior retinal detachment surgery can result in a myopic shift because of axial elongation of the eye from indentation of the scleral buckle. Refractive surgery can be considered in selected cases that have symptomatic anisometropia with good BCVA. The surgeon should determine whether the scleral buckle or conjunctival scarring will interfere with placement of the suction ring in preparation for creation of the LASIK flap. If it will, PRK may be considered instead of LASIK. Preoperative pathology, including preexisting macular pathology, will continue to limit UCVA and BCVA after refractive surgery. There are no published long-term series of the results of excimer laser vision correction in patients with prior retinal detachment surgery. Both the patient and the surgeon should realize that the final visual results may not be as predictable as after other refractive surgeries. Patients should also be aware that if the scleral buckle needs to be removed, the refractive error could change dramatically. Unexpected corneal steepening has been reported in patients undergoing LASIK with previously placed scleral buckles.

• Barequet IS, Levy J, Klemperer I, et al. Laser in situ keratomileusis for correction of myopia in eyes after retinal detachment surgery. J Refract Surg. 2005;21(2):191–193.

Excerpted from BCSC 2020-2021 series: Section 13 - Refractive Surgery. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.