Myopia, commonly known as nearsightedness, is a prevalent vision condition where distant objects appear blurry. High myopia, a more severe form, presents increased risks for eye health due to specific anatomical changes. Understanding these risks, particularly related to retinal detachment, is important for those with high myopia.
High Myopia and Retinal Detachment Explained
High myopia is defined as a spherical equivalent refractive error of -6.00 diopters or more, characterized by an excessive elongation of the eyeball, with an axial length greater than 26 millimeters. This anatomical change causes light to focus in front of the retina, resulting in blurred distance vision.
The retina is a thin layer of light-sensitive tissue at the back of the eye. Retinal detachment occurs when this retina separates from its underlying support tissue, which supplies it with oxygen and nutrients. This separation disrupts the retina’s function and can lead to permanent vision loss if not addressed promptly. A detached retina is considered a medical emergency.
Understanding the Risk
Individuals with high myopia face a significantly elevated risk of retinal detachment. The incidence of rhegmatogenous retinal detachment, the most common type, is approximately 39 times higher in high myopes than in non-myopes. For instance, the annual incidence is around 0.075% for eyes with myopia greater than -10.00 diopters, whereas it is about 0.015% for those with less than -4.75 diopters.
The elongated eyeball causes the retina and the sclera (the white outer layer of the eye) to become thinner and more stretched. This stretching makes the retina more prone to developing tears or holes. The vitreous gel, which fills the eye, also tends to liquefy and detach from the retina earlier in myopic eyes, a process known as posterior vitreous detachment (PVD). This PVD can exert traction on the thinned retina, potentially causing tears that allow fluid to seep underneath and lead to detachment.
Recognizing Key Symptoms
Symptoms of retinal detachment typically appear suddenly. These may include:
A significant increase in the number or size of floaters (small dark spots, specks, or squiggly lines).
Flashes of light (photopsia), often noticed in the peripheral vision.
A shadow or “curtain” appearing in the field of vision, which can expand.
Blurred vision.
Loss of side (peripheral) vision.
While retinal detachment is usually painless, any sudden onset of these symptoms warrants immediate medical evaluation by an eye care professional.
Emergency Action and Treatment
If any symptoms suggestive of retinal detachment appear, seek emergency medical attention immediately. Prompt evaluation by an ophthalmologist or a visit to the nearest emergency room is necessary to preserve vision, as delaying treatment significantly increases the risk of permanent vision loss.
Treatment for retinal detachment typically involves surgical procedures to reattach the retina. For retinal tears or small detachments, laser photocoagulation or cryopexy (freezing treatment) can be used to seal the tears.
For more extensive detachments, common surgical approaches include scleral buckling, where a silicone band is placed on the outside of the eye, or vitrectomy, which involves removing the vitreous gel and replacing it with a gas or oil bubble. Pneumatic retinopexy, another option, involves injecting a gas bubble into the eye to push the retina back into position.
Proactive Monitoring and Care
For individuals with high myopia, proactive monitoring and consistent eye care are important. Regular, comprehensive dilated eye exams with an ophthalmologist are recommended to monitor the health of the retina and detect early signs of tears or detachment. These annual examinations allow eye care professionals to assess the retina thoroughly, especially the peripheral areas that are more susceptible to thinning and tears in myopic eyes.
Beyond routine check-ups, individuals with high myopia should remain vigilant about their vision and report any new or worsening symptoms to their eye doctor immediately. While most daily activities are safe, it is advisable to discuss with an eye care professional whether certain activities that involve direct head or eye trauma, such as contact sports, should be limited or avoided.