Vitreo-Retinal & Uveitis Services

Our retina department provide following facilities:-

1. OCT (Optical Coherence Tomography)  – To investigate retinal diseases.
2. FFA (Digital Fundus Camera) – To investigate retinal disease.
3. B Scan-To investigate retinal & vitreous diseases
4. Green Laser- For Diabetic Retinopathy
5. Intravitreal Injections (Avastin, Lucentis, Eylea)
6. All kinds of Diabetic Retinopathy Treatment
7. All kinds of Retinal Detachment Surgeries.
8. Vitreo-Retinal Implants (Ozurdex, Recisert)
9. Lasers for retinopathy of Prematurity.
10. Sutureless vitreo-retinal surgery.

Diabetic retinopathy

Diabetic retinopathy, also known as diabetic eye disease, is a medical condition in which damage occurs to the retina due to diabetes mellitus. It is a leading cause of blindness.

Diabetic retinopathy affects up to 80 percent of those who have had diabetes for 20 years or more. At least 90% of new cases could be reduced with proper treatment and monitoring of the eyes. The longer a person has diabetes, the higher his or her chances of developing diabetic retinopathy. Each year in the United States, diabetic retinopathy accounts for 12% of all new cases of blindness. It is also the leading cause of blindness in people aged 20 to 64.

Signs and symptoms

Diabetic retinopathy often has no early warning signs. Even macular edema, which can cause rapid vision loss, may not have any warning signs for some time. In general, however, a person with macular edema is likely to have blurred vision, making it hard to do things like read or drive. In some cases, the vision will get better or worse during the day.

The first stage, called non-proliferative diabetic retinopathy (NPDR), has no symptoms. Patients may not notice the signs and have 20/20 vision. The only way to detect NPDR is by fundus photography, in which microaneurysms (microscopic blood-filled bulges in the artery walls) can be seen. If there is reduced vision, fluorescein angiography can show narrowing or blocked retinal blood vessels clearly (lack of blood flow or retinal ischemia).

Macular edema, in which blood vessels leak their contents into the macular region, can occur at any stage of NPDR. Its symptoms are blurred vision and darkened or distorted images that are not the same in both eyes. Ten percent (10%) of diabetic patients will have vision loss related to macular edema. Optical Coherence Tomography can show areas of retinal thickening due to fluid accumulation from macular edema.

In the second stage, abnormal new blood vessels (neovascularisation) form at the back of the eye as part of proliferative diabetic retinopathy (PDR); these can burst and bleed (vitreous hemorrhage) and blur the vision, because these new blood vessels are fragile. The first time this bleeding occurs, it may not be very severe. In most cases, it will leave just a few specks of blood, or spots floating in a person’s visual field, though the spots often go away after a few hours.

These spots are often followed within a few days or weeks by a much greater leakage of blood, which blurs the vision. In extreme cases, a person may only be able to tell light from dark in that eye. It may take the blood anywhere from a few days to months or even years to clear from the inside of the eye, and in some cases the blood will not clear. These types of large hemorrhages tend to happen more than once, often during sleep.

On funduscopic exam, a doctor will see cotton wool spots, flame hemorrhages (similar lesions are also caused by the alpha-toxin of Clostridium novyi), and dot-blot hemorrhages.

Diagnosis

Diabetic retinopathy is detected during an eye examination that includes:

• Visual acuity test: Uses an eye chart to measure how well a person sees at various distances (i.e., visual acuity).
• Pupil dilatation: The eye care professional places drops into the eye to dilate the pupil. This allows him or her to see more of the retina and look for signs of diabetic retinopathy. After the examination, close-up vision may remain blurred for several hours.
• Ophthalmoscopy or fundus photography: Ophthalmoscopy is an examination of the retina in which the eye care professional: (1) looks through a slit lamp biomicroscope with a special magnifying lens that provides a narrow view of the retina, or (2) wearing a headset (indirect ophthalmoscope) with a bright light, looks through a special magnifying glass and gains a wide view of the retina. Hand-held ophthalmoscopy is insufficient to rule out significant and treatable diabetic retinopathy. Fundus photography generally captures considerably larger areas of the fundus, and has the advantage of photo documentation for future reference, as well as availing the image to be examined by a specialist at another location and/or time.
• Fundus Fluorescein angiography (FFA): This is an imaging technique which relies on the circulation of fluorescein dye to show staining, leakage, or non-perfusion of the retinal and choroidal vasculature.
• Optical coherence tomography (OCT): This is an optical imaging modality based upon interference, and analogous to ultrasound. It produces cross-sectional images of the retina (B-scans) which can be used to measure the thickness of the retina and to resolve its major layers, allowing the observation of swelling.

The eye care professional will look at the retina for early signs of the disease, such as:

1. leaking blood vessels,
2. retinal swelling, such as macular edema,
3. pale, fatty deposits on the retina (exudates) – signs of leaking blood vessels,
4. damaged nerve tissue (neuropathy), and
5. any changes in the blood vessels.

If macular edema is suspected, FFA and sometimes OCT may be performed.

Diabetic retinopathy also affects microcirculation thorough the body. A recent study showed assessment of conjunctival microvascular hemodynamics such as vessel diameter, red blood cell velocity and wall shear stress can be useful for diagnosis and screening of diabetic retinopathy. Furthermore, the pattern of conjunctival microvessels was shown to be useful for rapid monitoring and diagnosis of different stages of diabetic retinopathy.

In April 2018 the FDA approved a similar device called IDx-DR. IDx-DR is an AI diagnostic system that autonomously analyzes images of the retina for signs of diabetic retinopathy. As an autonomous, AI-based system, IDx-DR is unique in that it makes an assessment without the need for a clinician to also interpret the image or results, making it usable by health care providers who may not normally be involved in eye care.

Google is testing a cloud algorithm that scans photos of the eye for signs of retinopathy. The algorithm still requires FDA approval.

According to a DRSS user manual, poor quality images (which may apply to other methods) may be caused by cataract, poor dilation, ptosis, external ocular condition, or learning difficulties. There may be artefacts caused by dust, dirt, condensation, or smudge.

Management

There are three major treatments for diabetic retinopathy, which are very effective in reducing vision loss from this disease. In fact, even people with advanced retinopathy have a 95 percent chance of keeping their vision when they get treatment before the retina is severely damaged. These three treatments are laser surgery, injection of corticosteroids or anti-VEGF agents into the eye, and vitrectomy.

Although these treatments are very successful (in slowing or stopping further vision loss), they do not cure diabetic retinopathy. Caution should be exercised in treatment with laser surgery since it causes a loss of retinal tissue. It is often more prudent to inject triamcinolone or anti-VEGF drugs. In some patients it results in a marked increase of vision, especially if there is an edema of the macula.

Avoiding tobacco use and correction of associated hypertension are important therapeutic measures in the management of diabetic retinopathy.

Obstructive sleep apnea (OSA) has been associated with a higher incidence of diabetic eye disease due to blood desaturation caused by intermittent upper airway obstructions. Treatment for OSA can help reduce the risk of diabetic complications.

The best way of preventing the onset and delaying the progression of diabetic retinopathy is to monitor it vigilantly and achieve optimal glycemic control.

Since 2008 there have been other therapies (e.g. kinase inhibitors and anti-VEGF) drugs available.

Laser photocoagulation

Laser photocoagulation can be used in two scenarios for the treatment of diabetic retinopathy. It can be used to treat macular edema by creating a Modified Grid at the posterior pole and it can be used for panretinal coagulation for controlling neovascularization. It is widely used for early stages of proliferative retinopathy.

Modified grid

A ‘C’ shaped area around the macula is treated with low intensity small burns. This helps in clearing the macular edema.

Panretinal

Panretinal photocoagulation, or PRP (also called scatter laser treatment), is used to treat proliferative diabetic retinopathy (PDR). The goal is to create 1,600 – 2,000 burns in the retina with the hope of reducing the retina’s oxygen demand, and hence the possibility of ischemia. It is done in multiple sittings.

In treating advanced diabetic retinopathy, the burns are used to destroy the abnormal blood vessels that form in the retina. This has been shown to reduce the risk of severe vision loss for eyes at risk by 50%.

Before using the laser, the ophthalmologist dilates the pupil and applies anaesthetic drops to numb the eye. In some cases, the doctor also may numb the area behind the eye to reduce discomfort. The patient sits facing the laser machine while the doctor holds a special lens on the eye. The physician can use a single spot laser or a pattern scan laser for two dimensional patterns such as squares, rings and arcs. During the procedure, the patient will see flashes of light. These flashes often create an uncomfortable stinging sensation for the patient. After the laser treatment, patients should be advised not to drive for a few hours while the pupils are still dilated. Vision will most likely remain blurry for the rest of the day. Though there should not be much pain in the eye itself, an ice-cream headache like pain may last for hours afterwards.

Patients will lose some of their peripheral vision after this surgery although it may be barely noticeable by the patient. The procedure does however save the center of the patient’s sight. Laser surgery may also slightly reduce colour and night vision.

A person with proliferative retinopathy will always be at risk for new bleeding, as well as glaucoma, a complication from the new blood vessels. This means that multiple treatments may be required to protect vision.

Medications

Intravitreal triamcinolone acetonide

Triamcinolone is a long acting steroid preparation. When injected in the vitreous cavity, it decreases the macular edema (thickening of the retina at the macula) caused due to diabetic maculopathy, and results in an increase in visual acuity. The effect of triamcinolone is transient, lasting up to three months, which necessitates repeated injections for maintaining the beneficial effect. Best results of intravitreal Triamcinolone have been found in eyes that have already undergone cataract surgery. Complications of intravitreal injection of triamcinolone include cataract, steroid-induced glaucoma and endophthalmitis. A systematic review found evidence that eyes treated with the intravitreal injection of triamcinolone had better visual acuity outcomes compared to eyes treated with macular laser grid photocoagulation, or sham injections.

Intravitreal anti-VEGF

There are good results from multiple doses of Intravitreal injections of anti-VEGF drugs such as Bevacizumab. A 2017 systematic review update found moderate evidence that Aflibercept may have advantages in improving visual outcomes over Bevacizumab and Ranibizumab, after one year. Present recommended treatment for diabetic macular edema is Modified Grid laser photocoagulation combined with multiple injections of anti-VEGF drugs.

Surgery

Instead of laser surgery, some people require a vitrectomy to restore vision. A vitrectomy is performed when there is a lot of blood in the vitreous. It involves removing the cloudy vitreous and replacing it with a saline solution.

Studies show that people who have a vitrectomy soon after a large hemorrhage are more likely to protect their vision than someone who waits to have the operation. Early vitrectomy is especially effective in people with insulin-dependent diabetes, who may be at greater risk of blindness from a hemorrhage into the eye.

Vitrectomy is often done under local anesthesia. The doctor makes a tiny incision in the sclera, or white of the eye. Next, a small instrument is placed into the eye to remove the vitreous and insert the saline solution into the eye.

Patients may be able to return home soon after the vitrectomy, or may be asked to stay in the hospital overnight. After the operation, the eye will be red and sensitive, and patients usually need to wear an eyepatch for a few days or weeks to protect the eye. Medicated eye drops are also prescribed to protect against infection.

Vitrectomy is frequently combined with other modalities of treatment.

UVEITIS

Uveitis is the inflammation of the uvea, the pigmented layer that lies between the inner retina and the outer fibrous layer composed of the sclera and cornea. The uvea consists of the middle layer of pigmented vascular structures of the eye and includes the iris, ciliary body, and choroid. Uveitis is an ophthalmic emergency and requires a thorough examination by an optometrist or ophthalmologist and urgent treatment to control the inflammation. It is often associated with other ocular problems.

Classification Uveitis is classified anatomically into anterior, intermediate, posterior, and panuveitic forms—based on the part of the eye primarily affected. Prior to the twentieth century, uveitis was typically referred to in English as “ophthalmia.”

Anterior uveitis includes iridocyclitis and iritis. Iritis is the inflammation of the anterior chamber and iris. Iridocyclitis is inflammation of iris and the ciliary body with inflammation predominantly confined to ciliary body. Anywhere from two-thirds to 90% of uveitis cases are anterior in location. This condition can occur as a single episode and subside with proper treatment or may take on a recurrent or chronic nature.

Intermediate uveitis, also known as pars planitis, consists of vitritis—which is inflammation of cells in the vitreous cavity, sometimes with snowbanking, or deposition of inflammatory material on the pars plana. There are also “snowballs,” which are inflammatory cells in the vitreous.

Posterior uveitis or chorioretinitis is the inflammation of the retina and choroid.

Pan-uveitis is the inflammation of all layers of the uvea(iris, ciliary body and choroid).

Signs and symptoms

ANTERIOR UVEITIS

• Burning of the eye
• Redness of the eye
• Blurred vision
• Photophobia or sensitivity to light
• Irregular pupil
• Blacked out sclera
• Headaches
• Signs of anterior uveitis include dilated ciliary vessels, presence of cells and flare in the anterior chamber, and keratic precipitates (“KP”) on the posterior surface of the cornea. In severe inflammation there may be evidence of a hypopyon. Old episodes of uveitis are identified by pigment deposits on lens, KPs, and festooned pupil on dilation of pupil.
• Busacca nodules, inflammatory nodules located on the surface of the iris in granulomatous forms of anterior uveitis such as Fuchs heterochromic iridocyclitis (FHI).
• Synechia

INTERMEDIATE UVEITIS

Most common:

• Floaters, which are dark spots that float in the visual field
• Blurred vision
• Intermediate uveitis normally only affects one eye. Less common is the presence of pain and photophobia.

POSTERIOR UVEITIS

Inflammation in the back of the eye is commonly characterized by:
• Floaters
• Blurred vision
• Photopsia or seeing flashing lights

Causes

Uveitis is usually an isolated illness, but can be associated with many other medical conditions.

In anterior uveitis, no associated condition or syndrome is found in approximately one-half of cases. However, anterior uveitis is often one of the syndromes associated with HLA-B27. Presence of this type of HLA allele has a relative risk of evolving this disease by approximately 15%.

The most common form of uveitis is acute anterior uveitis (AAU). It is most commonly associated with HLA-B27, which has important features: HLA-B27 AAU can be associated with ocular inflammation alone or in association with systemic disease. HLA-B27 AAU has characteristic clinical features including male preponderance, unilateral alternating acute onset, a non-granulomatous appearance, and frequent recurrences, whereas HLA-B27 negative AAU has an equivalent male to female onset, bilateral chronic course, and more frequent granulomatous appearance. Rheumatoid arthritis is not uncommon in Asian countries as a significant association of uveitis.

a) Noninfectious or autoimmune causes

• Behcet’s disease
• Crohn’s disease
• Fuchs heterochromic iridocyclitis
• Granulomatosis with polyangiitis
• HLA-B27 related uveitis
• Juvenile idiopathic arthritis
• Sarcoidosis
• Spondyloarthritis
• Sympathetic ophthalmia
• Tubulointerstitial nephritis and uveitis syndrome

b) Infectious causes

Uveitis may be an immune response to fight an infection inside the eye. While representing the minority of patients with uveitis, such possible infections include:

• Brucellosis
• Herpesviruses
• Leptospirosis
• Lyme disease
• Presumed ocular histoplasmosis syndrome
• Syphilis
• Toxocariasis
• Toxoplasmic chorioretinitis
• Tuberculosis
• Zika fever

c) Associated with systemic diseases

Systemic disorders that can be associated with uveitis include:[9][10]

• Ankylosing spondylitis
• Behcet’s disease
• Chronic granulomatous disease
• Enthesitis
• Inflammatory bowel disease
• Juvenile rheumatoid arthritis
• Kawasaki’s disease
• Multiple sclerosis
• Polyarteritis nodosa
• Psoriatic arthritis
• Reactive arthritis
• Sarcoidosis
• Systemic lupus erythematosus
• Vogt–Koyanagi–Harada disease
• Whipple’s disease

d) Drug related side effects

• Rifabutin, a derivative of Rifampin, has been shown to cause uveitis.
• Several reports suggest the use of quinolones, especially Moxifloxacin, may lead to uveitis.
• All of the widely administered vaccines have been reported to cause uveitis.

e) White Dot syndromes

Occasionally, uveitis is not associated with a systemic condition: the inflammation is confined to the eye and has unknown cause. In some of these cases, the presentation in the eye is characteristic of a described syndrome, which are called white dot syndromes, and include the following diagnoses:

• Acute posterior multifocal placoid pigment epitheliopathy
• Birdshot chorioretinopathy
• Multifocal choroiditis and panuveitis
• Multiple evanescent white dot syndrome
• Punctate inner choroiditis
• Serpiginous choroiditis
• Acute zonal occult outer retinopathy

f) Masquerade syndromes

Masquerade syndromes are those conditions that include the presence of intraocular cells but are not due to immune-mediated uveitis entities. These may be divided into neoplastic and non-neoplastic conditions.

i) Non-neoplastic:

• Retinitis pigmentosa

• Intraocular foreign body

• Juvenile xanthogranuloma

• Retinal detachment

ii) Neoplastic:

• Retinoblastoma

• Lymphoma

• Malignant melanoma

• Leukemia

• Reticulum cell sarcoma

Diagnosis

• Keratic precipitates

• Diagnosis includes dilated fundus examination to rule out posterior uveitis, which presents with white spots acsross the retina along with retinitis and vasculitis.

• Laboratory testing is usually used to diagnose specific underlying diseases, including rheumatologic tests (e.g. antinuclear antibody, rheumatoid factor) and serology for infectious diseases (Syphilis, Toxoplasmosis, Tuberculosis).

• Major histocompatibility antigen testing may be performed to investigate genetic susceptibility to uveitis. The most common antigens include HLA-B27, HLA-A29 (in Birdshot Chorioretinopathy) and HLA-B51 (in Behcet disease).

• Radiology X-ray may be used to show coexisting arthritis and chest X-ray may be helpful in sarcoidosis.

Treatment

Uveitis is typically treated with glucocorticoid steroids, either as topical eye drops (Prednisolone acetate) or as oral therapy. Prior to the administration of corticosteroids, corneal ulcers must be ruled out. This is typically done using a fluoresence dye test.In addition to corticosteroids, topical cycloplegics, such as Atropine or Homatropine, may be used. Successful treatment of active uveitis increases T-regulatory cells in the eye, which likely contributes to disease regression. In some cases an injection of posterior subtenon Triamcinolone Acetate may also be given to reduce the swelling of the eye.

Antimetabolite medications, such as Methotrexate are often used for recalcitrant or more aggressive cases of uveitis. Experimental treatments with Infliximab or other anti-TNF infusions may prove helpful.

The anti-diabetic drug Metformin is reported to inhibit the process that causes the inflammation in uveitis.

In the case of herpetic uveitis, anti-viral medications, such as Valaciclovir or Aciclovir, may be administered to treat the causative viral infection.

Prognosis

The prognosis is generally good for those who receive prompt diagnosis and treatment, but serious complication including cataracts, glaucoma, band keratopathy, macular edema and permanent vision loss may result if left untreated. The type of uveitis, as well as its severity, duration, and responsiveness to treatment or any associated illnesses, all factor into the outlook.