Pathological Myopia Case Update
A posterior staphyloma is considered a hallmark finding of pathological myopia.1,2 The definition of pathological myopia has been recently updated and is defined as the presence of myopic chorioretinal atrophy equal to or more severe than diffuse atrophy or the presence of a posterior staphyloma. More severe findings include patchy chorioretinal atrophy, macular atrophy, lacquer cracks, and choroidal neovascularization 1,3 A posterior staphyloma is not a benign finding; the presence of a posterior staphyloma increases the likelihood of myopic maculopathy including choroidal neovascularization, atrophy, and traction maculopathy. 1,4
Technology has made it easier to detect early signs of structural changes due to myopia. In this case, OCT was used to detect mini bulges that may not have been detected on fundoscopy. Widefield OCT imaging may be more appropriate for detecting posterior staphylomas as the most common form is a wide macular type.1 The borders of a staphyloma are characterized by a change in the radius of curvature of the sclera and overlying tissue. Traditional OCT imaging may miss the change in radius of curvature in these wide lesions, a widefield OCT has an increased likelihood of intersecting the lesion borders. In addition to changes in the sclera, the choroid is significantly thin within the staphyloma, especially at the lesion borders.1,5 This thinned choroid increases the likelihood of myopic pathology such as neovascularization and atrophy. Once a staphyloma is detected, there is a higher likelihood of progression to more serious and sight threatening forms of myopic degeneration.1,4
The prevalence of myopia and more specifically high myopia is higher than ever before and continues to increase from year to year around the world.2,6 Research in the field of myopia control has yielded viable options to decrease the rate of myopia progression in young patients. Orthokeratology, soft multifocal contact lenses, and atropine therapy have all been shown to slow the progression of myopia.6 Further long term studies are needed to determine whether these effects are lasting after the discontinuation of treatment. There is currently much discussion regarding who is a good candidate for myopia control. General considerations include age, current level of myopia, rate of progression, family history, and patient preferences. Early fundus findings indicating degenerative changes due to myopia should be considered as well.
In addition to optical and topical treatments, surgical reinforcement and scleral cross-linking are being studied as viable options for preventing myopic degenerative changes.1,3 In a 2016 study by Dotan et al. researchers found that scleral cross-linking prevented occlusion induced axial-elongation in rabbits.7 The study used riboflavin and UVA radiation similar to the cross-linking procedure used to slow the progression of corneal ectasias. Another study in 2018 by Lin et al. used a sub-Tenon’s injection of glyceraldehyde for scleral cross linking and found similar results; cross-linking prevented lens-induced axial elongation in rabbits.8 Continued research in the prevention of high myopia and myopic degeneration is needed as rates of myopia rise to unprecedented levels.
- Ohno-Matsui K, Jonas Posterior Staphyloma in Pathologic Myopia. Progress in Retinal and Eye Research 2019;70:99–109.
- Jones D, Luensmann The Prevalence and Impact of High Myopia. Eye & Contact Lens 2012;38:188–196.
- Ohno-Matsui K, Lai TYY, Chi-Chun L, Cheung CMG. International Photographic Classification and Grading System for Myopic Maculopathy. American Journal of Ophthalmology 2015:159;877–883.
- Zheng F, Wong CW, Sabanayagam C, et al. Prevalence, Risk Factors and Impact of Posterior Staphyloma Diagnosed from Wide‐field Optical Coherence Tomography in Singapore Adults with High Myopia. Acta ophthalmologica 2020.
- Fang Y, Ran Du MD, Nagaoka N, et al. OCT-Based Diagnostic Criteria for Different Stages of Myopic Maculopathy. Ophthalmology 2019:126;1018–1032.
- Walline JJ. Myopia Control: A Review. Eye & Contact Lens: Science & Clinical Practice 2016:42; 3–8.
- Dotan A, Kremer I, Gal-Or O, Livnat T et al. Scleral Cross-Linking Using Riboflavin and Ultraviolet-A Radiation for Prevention of Axial Myopia in a Rabbit Model. Journal of Visualized Experiments 2016:110.
- Lin X, Naidu RK, Dai J, Zhou X et al. Scleral Cross-Linking Using Glyceraldehyde for the Prevention of Axial Elongation in the Rabbit: Blocked Axial Elongation and Altered Scleral Microstructure. Current Eye Research 2018:44;162–171.