The light that enters the eye passes through various transparent tissues and focuses on the photosensitive tissue at the back portion of the eye. This photosensitive specialized tissue is called the retina. Retina has ten different layers, each responsible for specific functions. This layer gathers the light energy that enters the eye. It converts to electrical energy that reaches the brain, helping us see things around us. Any damage to the retina can cause a severe drop in visual functions.
Figure 1:
a) Shows the eye’s cross-sectional view focusing on the retina and its ten layers.
b) shows how light rays from an object falls on the retina, where the light energy received is converted into electrical energy and reaches the brain.
Retinal detachment (RD) is a sight-threatening condition requiring immediate attention and care. RD can even lead to complete blindness if not diagnosed and treated on time. Retinal detachment is the separation of the retinal layers from the bed of the retina, which is called the Retinal Pigmented Epithelium (RPE).
RD can be caused due to many reasons like the presence of a hole in the retina (Rhegmatogenous retinal detachment), or formation of an extra membrane that pulls the retina away from RPE (tractional retinal detachment) or can be because of any abnormality in water transport across RPE (Exudative retinal detachment).
Figure 2: Shows the cross-sectional view of the retina detached from RPE due to a retinal hole.
RD can occur in any eyes, though people with high minus power (myopia/short-sightedness), presence of holes or breaks in the retina (lattice), eye injury, family history of RD, people with certain genetic disorders such as Marfan’s syndrome, Stickler’s syndrome have a higher risk of developing RD. RD can also occur as a complication of cataract surgery too.
Patients with RD experience sudden loss or blurring of vision in the affected eye. If the RD is partial, patients might experience a sudden loss of vision or shadow on one side of their field of vision.
Patients may experience sudden flashes of light in the initial stages even before the onset of loss of vision. It is essential to consult an Ophthalmologist (Esp. a retina specialist) immediately when symptoms like flashes of light, sudden diminishing of vision or partial obstruction in the visual field are observed. Ophthalmologist aims to restore the vision by performing surgery to attach the retinal layers back to RPE.
RD requires surgery to close the hole that caused detachment and create a strong adhesion between the retinal layers and underlying structures to prevent re-detachment. There are different RD surgeries, namely, sclera buckle, vitrectomy, Pneumatic retinopexy and laser retinopexy.
In the scleral buckle procedure, a silicone band will be placed in the white portion (sclera) of the eye to push the eyeball close to the tear and help to reattach the retina. Scleral bucking is a commonly performed procedure for non-complicated RD’s and has a high success rate. Scleral buckling is not an option for complicated RDs with pre-existing retinal conditions.
In a vitrectomy, an ophthalmologist aims to attach the retina by removing a small amount of clear fluid (vitreous gel) from the eye and replacing it with a gas bubble. This gas bubble holds the retina in place. While the gas bubble is in position, the vision will be blurred and eventually becomes clear when the bubble absorbed, which takes 2 to 4 weeks or sometimes three months on long-acting gases.
When there is a small retinal detachment, Pneumatic retinopexy is performed, where a gas bubble can be injected into the vitreous without removing the vitreous gel. This gas bubble will then press the retina, and it helps to reattach the retina to its position.
Eventually, procedures like cryotherapy or laser can be done to seal the holes or tears in the retina. Depending on the extent of a gas bubble’s presence, the vision can be blurred; hence, this surgery is not commonly performed and has a comparatively lower success rate than other surgeries.
How successful is the RD surgery?
RD surgeries are usually successful at reattaching the retina. However, vision recovery depends on various factors such as the extent of retinal detachment, any existing eye problems, etc.
Vision recovery is generally good if the centre of the retina is attached. The vision recovery might be poor when the centre of the retina also detaches when your retinal detachment involves the centre part of your retina (macula).
If the surgery is done early, visual improvement will be good; however, one can experience distortions in their vision.
Timely treatment of retinal detachment is essential as the retina might not regain the vision if detachment is old. In a few cases RD can be recurrent and may require repeated surgeries. The rate of retinal reattachment after single surgery varies with a different type of surgery. The reattachment rate ranges from 77 to 87%. Evidence shows an 87.7% reattachment rate post vitrectomy, 75.5% post pneumatic retinopexy and 78% post scleral buckling.
Conclusion:
RD is a vision-threatening condition that requires early intervention. Surgical techniques and outcomes have been improved in the last few decades with modern techniques.
The decision on the type of surgery depends on various factors—the success rate range from 77 to 87%. The critical factor determining the success rate of the RD surgery is early diagnosis and prompt treatment.
Hence it is essential to consult an ophthalmologist immediately when you experience a sudden loss of vision, flashes of light or shadowing in one side of the visual field.
