Clipping Board » Disease & Prevention ─ Understanding diseases, prevention is better than cure.
Update Date: 2008/09/08 04:09
By Cai Wufu
Retinal detachment is a serious eye condition that can potentially lead to blindness. However, if patients remain vigilant and detect it early, timely treatment can not only be more straightforward but also prevent the tragedy of losing sight.
There are several types of retinal detachment, but unless specified otherwise, it generally refers to rhegmatogenous retinal detachment. Degeneration and thinning of the peripheral retina lead to the formation of holes (tears or round holes), and the vitreous, which has similarly degenerated from a gel-like to a watery consistency, seeps through these holes into the subretinal space. Combined with abnormal traction of the vitreous on the retina, these three factors interact to cause retinal detachment, presenting the following visual symptoms:
● Floaters: When holes form, retinal pigment epithelial cells are released into the vitreous through these holes, or retinal capillaries rupture, allowing blood to seep into the vitreous. Patients may suddenly see numerous small black dots clustering together and floating in their vision, unable to define a specific shape, often described as resembling clouds, dust, or rain. Sometimes, the blood can be absorbed on its own, causing the floaters to disappear after 2 or 3 days, which can misleadingly give the impression of improvement.
● Flashes: This is caused by the posterior vitreous membrane pulling on the retina, mechanically stimulating the photoreceptor cells. These flashes typically occur once or two to three times with eye movement. They usually appear in the upper outer part of the visual field, are more noticeable in the dark, and can be easily overlooked in bright light. Closing the eyes and moving them makes the flashes most noticeable.
● Visual field loss: Floaters and flashes appear when holes form, but once the retina detaches, visual field loss occurs. The detached retina loses its nutrient supply from the choroid, temporarily losing visual function, and the corresponding visual field is obscured by a shadow like a curtain. As the detachment expands, the shadow also enlarges.
If the detachment involves the macula, vision drops sharply, and objects may appear distorted or wavy. If the entire retina detaches, the field of vision becomes completely dark, significantly increasing the risk of blindness. The speed of detachment varies greatly; some people may experience complete detachment in an instant.
Visual field loss can occur in any direction but always extends from the periphery towards the center. It may improve when lying down but reappears shortly after getting up and moving around. The visual fields of both eyes are complementary, so covering one eye and using the other can easily reveal the visual field loss.
Additionally, retinal detachment can sometimes be completely asymptomatic. High-risk groups include those with high myopia, diagnosed lattice degeneration of the peripheral retina, post-cataract or vitrectomy surgery, trauma, diabetes, or a personal or family history of retinal detachment. Regular dilated eye exams are recommended for these individuals. (The author is the director of Banqiao Cai Wufu Eye Clinic)
Source: http:/ / tw. news. yahoo. com/ art……url/ d/ a/ 080908/ 78/ 15i5y. html
Retinal Detachment Warning: Dark Shadows in Vision
By Cai Wufu
Retinal detachment is a serious eye condition that can potentially lead to blindness. However, if patients remain vigilant and detect it early, timely treatment can not only be more straightforward but also prevent the tragedy of losing sight.
There are several types of retinal detachment, but unless specified otherwise, it generally refers to rhegmatogenous retinal detachment. Degeneration and thinning of the peripheral retina lead to the formation of holes (tears or round holes), and the vitreous, which has similarly degenerated from a gel-like to a watery consistency, seeps through these holes into the subretinal space. Combined with abnormal traction of the vitreous on the retina, these three factors interact to cause retinal detachment, presenting the following visual symptoms:
● Floaters: When holes form, retinal pigment epithelial cells are released into the vitreous through these holes, or retinal capillaries rupture, allowing blood to seep into the vitreous. Patients may suddenly see numerous small black dots clustering together and floating in their vision, unable to define a specific shape, often described as resembling clouds, dust, or rain. Sometimes, the blood can be absorbed on its own, causing the floaters to disappear after 2 or 3 days, which can misleadingly give the impression of improvement.
● Flashes: This is caused by the posterior vitreous membrane pulling on the retina, mechanically stimulating the photoreceptor cells. These flashes typically occur once or two to three times with eye movement. They usually appear in the upper outer part of the visual field, are more noticeable in the dark, and can be easily overlooked in bright light. Closing the eyes and moving them makes the flashes most noticeable.
● Visual field loss: Floaters and flashes appear when holes form, but once the retina detaches, visual field loss occurs. The detached retina loses its nutrient supply from the choroid, temporarily losing visual function, and the corresponding visual field is obscured by a shadow like a curtain. As the detachment expands, the shadow also enlarges.
If the detachment involves the macula, vision drops sharply, and objects may appear distorted or wavy. If the entire retina detaches, the field of vision becomes completely dark, significantly increasing the risk of blindness. The speed of detachment varies greatly; some people may experience complete detachment in an instant.
Visual field loss can occur in any direction but always extends from the periphery towards the center. It may improve when lying down but reappears shortly after getting up and moving around. The visual fields of both eyes are complementary, so covering one eye and using the other can easily reveal the visual field loss.
Additionally, retinal detachment can sometimes be completely asymptomatic. High-risk groups include those with high myopia, diagnosed lattice degeneration of the peripheral retina, post-cataract or vitrectomy surgery, trauma, diabetes, or a personal or family history of retinal detachment. Regular dilated eye exams are recommended for these individuals. (The author is the director of Banqiao Cai Wufu Eye Clinic)
Source: http:/ / tw. news. yahoo. com/ art……url/ d/ a/ 080908/ 78/ 15i5y. html