In Conversation with Doctors

 

Eye Diseases

by Assoc Prof Dr Tajunisah Iqbal, Consultant Ophthalmologist

1. What are some common eye diseases in adults?

Eye problems in adults can be of two types; firstly the ones that usually does not cause vision loss and secondly, the more sinister vision threatening eye diseases.

Under the first category, these conditions are problems such as refractive errors that can be corrected with prescription glasses, burning sensation, tearing and scratchy eye discomfort as a result of Dry Eye Syndromes, Allergic or Itchy eye problems Eye Strains due to computer/ gadgets over usage.

Lately, with the current MCO and work-at-home policy, many patients present to eye clinic with digital eye strains (Computer Vision Syndrome) and Dry Eye Syndromes. Even though these conditions are not vision-threatening, many patients suffer from annoying eye discomfort and vision problems that hampers their daily activities.

The second category of eye problems are more serious and need to be detected and managed early. These are diseases that are vision threatening and has the potentiality to cause blindness or permanent vision loss if not treated in time. Cataracts, Diabetic Retinopathies, Galucomas, Macular Degenerations and Retinal Detachments tend to fall into this category.

2. What are some symptoms that indicate vision loss or severe eye problems?

There are specific symptoms that give clue of sinister eye problems. Any time a person’s vision is disturbed or not how it used to be, especially if it occurs suddenly, rings an alarm bell and should be checked immediately. If the vision is blurry and progressively worsens over time despite wearing glasses, this usually indicates the occurrence of cataracts especially in older individuals. If the vision in one or both eyes appear distorted, meaning the images appear as wavy, or straight lines appearing as crooked, or there is a persistent black spot or scotoma in the center of the vision, this usually points towards a macula problem such as macular degeneration or bleed or macula hole. If the vision is suddenly reduced, and feels like a curtain coming down over the eye, especially with accompanying black specks floating in line of vision (floaters) or flashes of lights, this could indicate a serious Retinal Detachment disease. Primary open angle glaucoma is another serious eye disease where the symptoms are subtle and may not disturb the vision at first but as it progresses the patient gradually has a constricted visual field and in advanced stages the field is so narrowed that it appears like looking through a small hole. Diabetic retinopathy too falls under the category of Silent Killer of Vision where the symptoms are mild or absent in the initial stages but can quickly progress to irreversible vision loss if not caught early.

Pain in the eyes or around the eyes is another sinister symptom. For example, in cases of acute attacks of Angle Closure Glaucoma, the eye pain can be very severe with redness and tearing with associated severe headaches and sometimes vomiting. In cases of inflammation of the optic nerve, a condition known as Optic Neuritis, the pain is primarily felt on moving the eyeballs to right/left or up/down positions. In another eye disease known as Uveitis or inflammation of the uveal tissues of the eye, the pain is mainly felt on looking at a bright light source, causing the patient to be photophobic. Corneal abrasion, where the top layer of the corneal tissue is breached which can happen due to fingernail injuries or any sharp objects scratching the surface of the eye, is another painful condition that can keep one awake at night. Similarly, corneal ulcers, which we see quite a bit nowadays due to inappropriate use of contact lenses amongst the young and trendy, is both a painful and potentially blinding disease if not treated early. So in summary, the bottom line is, any eye condition that causes a lot of pain, redness and tearing with vision disturbances, is never good.

 3.How often should we have eye examination?

 It is best to have a detailed proper eye examination by an eye doctor at least once yearly. Eye exam by the optometrists or general practitioners may not be adequate especially if the individual has high risk for serious eye diseases such as retinal detachments, macula degeneration, glaucoma or diabetic retinopathy.

Anyone with a strong family history of glaucoma is adviced to check the eyes at least once yearly. With the current technology of Optical Coherence Topography (OCT), which the current investigative tool that can be easily done in the eye clinic and takes about 10 minutes to complete, early detection of glaucoma and retinal diseases can be easily done. If one is born with high myopia (or a high degree of short-sightedness), a fully dilated pupil for fundus examination to look for retinal holes or breaks is strongly recommended at least yearly to prevent retinal detachment. Diabetics without exemption, should get their eyes checked at least once a year despite having no vision symptoms as diabetic retinopathy is usually a silent disease as mentioned earlier.  Anyone above the age of 50 year old, are at risk of getting cataracts and should be checked thoroughly.

4. What are the treatments available for:

     a) Cataracts

Cataracts are clouding of the natural lens and causes progressive blurring of vision. There is no effective treatment for removal of cataracts other than surgery. Since the past one decade, the surgical technique for cataract removal has evolved to a modern, safe and effective method known as Phacoemulsification. During Phacoemulsification, a small opening is made at the edge of cornea and an ultrasonic handpiece is inserted to emulsify and aspirate the cloudy lens. A new artificial lens known as intraocular lens is then introduced through the small opening and takes the position of the original lens and remains permanent in the eye. The incision made in the cornea usually requires no stitching and heals naturally in a few days. With the current advanced lens technology, patients can now choose to be free of glasses to see well for near or far depending on the lens selection. It is usually done as a Daycare procedure with local anaesthesia either injected around the eye or given as topical numbing eye drops. This is currently a very popular method of cataract surgery with good results and high patient satisfaction.

      b) Age-Related Macular Macular Degeneration (AMD)

Currently there is no cure for AMD; the treatment is aimed to slow down the disease progression, to prevent severe vision loss and in some cases to improve vision as much as possible. Treatment for AMD depends on the stage of disease, whether in the early dry form or in the more advanced wet form.

Dry AMD is due to an accumulation of abnormal debri called drusens in the macula due to loss of retina cells function that occurs with advancing age. Most patients with dry AMD notice a gradual, painless vision loss that progresses with time. For dry AMD, there are no specific treatments to stop the drusens from forming. However, nutritional supplements containing antioxidant vitamins can reduce the risk of dry AMD progressing to the more serious sight-threatening wet AMD.

Wet AMD (also known as Exudative AMD) is a caused by abnormal growth of blood vessels in the retina that leaks fluids or blood into the back of the eye. Vision loss is usually rapid and more significant than those with dry AMD. Wet AMD accounts for 10-20% of AMD cases.

The main goal in wet AMD treatment is to shrink or stop the abnormal blood vessel growth and to prevent the leakage of fluid into the back of the eye. For this purpose, there are currently medications available known as Anti-Vasculoendothelial Growth Factors (anti-VEGF) that are injected directly into the affected eye. The injections are given within 1-3 months apart and may require up to 10-12 injections in the first year of treatment and subsequently reduced gradually over the next few years until the disease activity is stabilized. Additional laser treatments known as photodynamic therapy (PDT) are also available to treat resistant cases. For advanced AMD patients with severe vision loss, visual rehabilitation is recommended with the help of low vision aids such as magnifiers, telescopes and apps on digital devices to maximize vision potential.

      c) Retina Detachment

Retina detachment is a serious eye problem where the retina tissues get pulled away from each other either due to a break or hole in one of the retina layer (Rhegmatogenous type), or due to a tractional membrane pulling one of the layer away (Tractional type) or due to serous fluid accumulation between the two layers (Exudative type). Rhegmatogenous retinal detachment is considered an eye emergency; the faster the condition is detected and repaired, the better the chances of vision recovery.

The symptoms of rhegmatogenous retinal detachment (RRD) usually depend on the size of retinal breaks and its subsequent detachment. Small retinal breaks can be subtle and unrecognized whereas larger breaks can present with sudden appearance of large numbers of black specks or floaters in the field of vision with associated flashes of light in one or both eyes. A large RRD is often noticed by the patient as adark shadow or “ curtain” covering the field of vision. The patients at risk to get RRD are those with family history of RRD, those who have had serious eye injury before or eye surgeries such as cataract removals, those who have extreme shortsightedness (high myopia), those with posterior vitreous detachment or very mobile and degenerative vitreous and those with retina diseases such as retinoschisis or lattice degeneration.

The treatment for RRD will depend on how much the retina is detached and how big is the area of retina breaks or hole. If there is a small hole or tear in the retina, laser or freeze treatment (cryopexy) may be recommended to seal the tears or breaks in the retina. This is often performed as outpatient in the clinic.

If a larger part of the retina is detached, the patient will be advised to undergo a more complex eye surgery as an inpatient to reattach the retina. Your surgeon may opt to put in a scleral buckle that encircles the entire eye like a belt. This buckle will indent the wall of the eye and relieves some of the force caused by the vitreous tugging on the retina. In other cases, the surgeon may opt to perform vitrectomy, where the vitreous gel is removed and replaced with air, gas or silicone oil to help flatten and reattach the retina.  Sometimes, a second or subsequent surgeries may be needed if the retina detaches again. In general, the outcome of vision recovery is better if the area of detachment is smaller and does not involve the retina and if the surgery is performed earlier rather than later.

Hope the information provided above is useful. Remember that vision is a great gift and must be protected always. “ Of all the senses, Sight must be the most delightful” –Helen Keller.