Case Study
A 47-year-old female presented with progressively worsening myopia and a recent onset of visual distortion in her right eye. She had a history of high myopia since childhood, with a refractive error exceeding -10 diopters.
On fundus examination, the posterior segment of her right eye showed marked thinning of the sclera and choroid, with an outward bulging of the eye wall suggestive of posterior staphyloma.
Optical coherence tomography (OCT) revealed a significant posterior outpouching of the scleral wall, thinning of the retinal layers, and extensive choroidal atrophy.
The patient was diagnosed with myopic staphyloma. Treatment focused on regular monitoring to assess progression, and visual rehabilitation using specialized lenses.
Due to the risk of macular complications, a surgical referral for potential macular buckling was made.
Introduction
Staphyloma refers to an abnormal outward bulging of the wall of the eye due to thinning of the sclera, often involving the choroid and retina.
It can occur anywhere along the eye but is most commonly seen posteriorly in highly myopic eyes, where it is termed posterior staphyloma.
Staphylomas can be congenital, acquired (due to trauma or infection), or associated with diseases like high myopia and age-related degenerative changes.
This condition poses a serious risk to vision, as the associated scleral thinning can lead to complications such as retinal detachment, macular degeneration, and choroidal atrophy.
Pathophysiology
The development of staphyloma involves progressive thinning of the sclera, often accompanied by stretching of the choroid and retina.
In highly myopic eyes, the axial elongation predisposes to scleral weakening, leading to the outpouching characteristic of posterior staphyloma.
Over time, this stretching can cause significant structural changes in the retina and choroid, increasing the risk of complications like myopic macular degeneration, lacquer cracks, and choroidal neovascularization (CNV).
Chorioretinal atrophy is a hallmark of advanced staphyloma, contributing to progressive visual decline.
Epidemiology
Staphyloma is most commonly seen in individuals with high myopia, particularly in Asian populations where high myopia is more prevalent.
It is estimated that posterior staphyloma occurs in around 30% of highly myopic eyes with axial lengths exceeding 26.5 mm.
The condition is also associated with other degenerative diseases, such as retinitis pigmentosa, scleritis, and certain congenital conditions.
Its prevalence increases with age and the severity of myopia, with staphylomas often first detected in middle-aged individuals.
Clinical Features
Staphylomas can present in various parts of the eye, but posterior staphyloma is the most clinically significant due to its association with myopia.
Clinically, posterior staphyloma is characterized by the outward bulging of the sclera, resulting in significant visual distortion and potential complications like CNV or retinal detachment.
Patients typically report progressive myopia, visual distortion, and in advanced cases, central vision loss due to associated macular changes.
Examination Findings
- Fundoscopy: Shows scleral thinning and outward bulging, particularly in the posterior pole, with choroidal atrophy in advanced cases.
- OCT: Reveals thinning of retinal layers and the scleral outpouching characteristic of posterior staphyloma. It is essential for monitoring macular involvement.
- Ultrasound B-scan: Provides a clear image of the posterior staphyloma’s size and depth, particularly in cases where optical imaging is challenging.
Differential Diagnosis
- Retinoschisis
- Retinal detachment
- Macular degeneration
- Scleral ectasia
- Choroidal tumors
Management
The treatment of staphyloma focuses on monitoring for complications and addressing any visual impairment. Regular imaging using OCT and ultrasound is crucial for detecting progressive thinning, retinal detachment, or the development of CNV.
For patients with severe visual loss due to macular involvement, surgical options like macular buckling or scleral reinforcement can be considered.
Visual rehabilitation through corrective lenses or contact lenses is also important for maintaining quality of life. In advanced cases with macular CNV, anti-VEGF injections may be used to manage exudative complications.
Prognosis
The prognosis for staphyloma depends largely on the severity and location of the scleral thinning.
Posterior staphyloma associated with high myopia carries a high risk of visual decline due to complications like myopic macular degeneration, CNV, and retinal detachment.
Early detection and close monitoring are essential to prevent further visual loss. In cases where surgical intervention is possible, prognosis improves, particularly if macular involvement can be effectively managed.
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References
- Curtin, B. J. (1977). The posterior staphyloma in pathologic myopia. Transactions of the American Ophthalmological Society, 75, 67-86.
- Pruett, R. C. (1980). Complications associated with posterior staphyloma in pathologic myopia. Ophthalmology, 87(7), 678-684.
- Ohno-Matsui, K., Lai, T. Y. Y., Lai, C. C., & Cheung, C. M. G. (2016). Updates of pathologic myopia. Progress in Retinal and Eye Research, 52, 156-187.
- Wang, N. K., Lai, C. C., Chu, H. Y., Chen, Y. P., & Chen, K. J. (2018). Staphyloma and myopic traction maculopathy in eyes with pathologic myopia: Imaging features and surgical outcomes. Retina, 38(5), 1037-1051.
- Chen, S. N., & Lian, I. (2017). Surgical outcome of macular buckling for eyes with myopic macular hole retinal detachment with or without posterior staphyloma. Ophthalmology, 124(2), 239-241.
- Koh, V., Cheung, C. M. G., & Ohno-Matsui, K. (2019). Posterior staphyloma in pathologic myopia. Retina, 39(7), 1340-1345.
