Uveitis Chapter Notes | Ophthalmology - NEET PG PDF Download

IRIS

• The iris is a circular structure in the eye that measures about 12 mm in diameter. It has a central opening called the pupil, which is typically 3 to 4 mm in size.
• The iris is thinnest at its base, where it connects to the eye.
• The front surface of the iris is divided into two zones: the ciliary zone and the pupillary zone. These zones are separated by a zig-zag line known as the Collarette. This line marks the point where the pupillary membrane attaches to the iris.

Microscopic Structure of Iris

• The microscopic structure of the iris consists of four layers, listed from the front to the back:
  • The anterior limiting membrane forms the front layer of the iris.
  • The iris stroma is the second layer, containing blood vessels, nerves, and the muscles responsible for controlling the size of the pupil, including the sphincter pupillae (which constricts the pupil) and the dilator pupillae (which expands the pupil).
  • The anterior epithelial layer is the third layer, located behind the stroma.
  • The posterior pigmented epithelial layer is the innermost layer of the iris.
• The ciliary body is a part of the eye located behind the iris. It is considered a dangerous area because if it experiences trauma, it can trigger a severe immune response against uveal antigens. This response can lead to a condition called sympathetic ophthalmia, which affects both eyes.
• The ciliary body extends forward from the choroid at a region called the ora serrata and has a triangular shape in cross-section.
• The ciliary body consists of two main parts:
  • Pars plicata: This is the front part of the ciliary body, which has a folded appearance.
  • Pars plana: This is the flatter, posterior part of the ciliary body.

Microscopic Structure of Ciliary Body

• Supraciliary Lamina: This is the outermost layer of the ciliary body, made up of condensed stroma. It consists of pigmented collagen fibres.
• Stroma: The stroma of the ciliary body contains three types of fibres—longitudinal, circular, and radial fibres. It also has a vascular structure known as the major arterial circle.
• Pigmented Epithelium: This layer of pigmented epithelium is located beneath the stroma.
• Non-Pigmented Epithelium: The layer of non-pigmented epithelium is situated below the pigmented epithelium.
• Internal Limiting Membrane: This membrane forms the innermost boundary of the ciliary body.
• Choroid: The choroid has three layers from the outside in:
• Suprachoroidal Lamina: This is a thin membrane made of condensed collagen. The space between this membrane and the sclera is called the suprachoroidal space, which contains long and short posterior ciliary arteries.
• Stroma:The stroma of the choroid is composed of loose collagenous tissue and contains blood vessels arranged in three layers:
  • Haller’s Layer: This layer contains large blood vessels.
  • Sattler’s Layer: This layer consists of medium-sized blood vessels.
  • Choriocapillaris: This layer contains small blood vessels that nourish the outer layer of the retina.
• Basal Lamina: The basal lamina, known as Bruch’s Membrane, is located adjacent to the retinal pigment epithelium (RPE).

Blood Supply of Uveal Tract

Arterial supply:

• Short posterior ciliary arteries: These arteries originate from the ophthalmic artery as two main trunks, which then divide into 10–20 branches. They penetrate the sclera near the optic nerve and supply the choroid in segments.
• Long posterior ciliary arteries: There are two of these arteries, one nasal and one temporal. They pierce the sclera on either side of the optic nerve and travel through the suprachoroidal space to the ciliary muscle. At the front of the ciliary muscle, they connect with each other and the anterior ciliary arteries to form the Major Arterial Circle (Circulus Arteriosus Major).
• Anterior ciliary arteries: These arteries arise from muscular branches of the ophthalmic artery (seven in total). They move forward in the episclera, giving off branches to the sclera, limbus, and conjunctiva. They enter the ciliary muscle and connect with the two long posterior ciliary arteries to create the circulus arteriosus major near the iris root. Many branches from this circle extend towards the pupillary margin, where they connect to form the Circulus arteriosus minor.

Venous Drainage of the Eye

• Anterior ciliary veins are responsible for carrying blood solely from the ciliary muscles.
• Smaller veins from the sclera transport blood from the sclera.
• Vortex veins, also known as posterior ciliary veins, are four in number and located at 5 O’clock, 7 O’clock, 11 O’clock, and 1 O’clock.
• Two superior vortex veins connect to the superior ophthalmic vein, while two inferior vortex veins connect to the inferior ophthalmic vein.
• These veins drain the entire choroid and receive blood from small veins associated with the optic nerve head.
• Additionally, small veins may also drain blood from the retina.
• Anterior tributaries of these veins come from the iris, ciliary processes, ciliary muscles, and the anterior part of the choroid.

Uveitis

Uveitis is the inflammation of the uveal tract in the eye. The uveal tract consists of the iris, ciliary body, and choroid. Uveitis can affect different parts of the uveal tract and can be classified based on its anatomical location, clinical presentation, and pathological characteristics.

Classification of Uveitis

a. Anatomical Classification.

• Anterior Uveitis: This type involves inflammation of the iris and the pars plicata region of the ciliary body.
• Intermediate Uveitis: In this case, the inflammation is localized to the pars plana part of the ciliary body.
• Posterior Uveitis: This type affects the choroid, which is the posterior part of the uveal tract.
• Panuveitis: This is a more severe form where all parts of the uveal tissue are inflamed.

b. Clinical Classification.

• Acute Uveitis: Characterized by a sudden onset of inflammation.
• Chronic Uveitis: Involves long-standing or recurrent inflammation.

c. Pathological Classification.

• Granulomatous Uveitis: Involves the formation of granulomas, which are small areas of inflammation.
• Non-granulomatous Uveitis: Does not involve granuloma formation.

Masquerade Syndrome

• Masquerade syndrome is a condition where certain diseases mimic the symptoms of uveitis.
• Conditions that can cause uveitis include:
• Intraocular Lymphoma: A type of cancer that occurs in the lymphatic tissue of the eye.
• Retinoblastoma: A rare type of eye cancer that typically occurs in young children.
• Choroidal Melanoma: A cancer that develops in the melanocytes of the choroid.
• Leukemia: A type of cancer that affects the blood and bone marrow.
• Amyloidosis: A condition characterized by the buildup of amyloid proteins in organs and tissues.

Anterior Uveitis

Anterior uveitis is a condition characterized by inflammation of the iris and the front part of the ciliary body. When only the iris is inflamed, it is called iritis, and when both the iris and the front section of the ciliary body are involved, it is referred to as iridocyclitis.

Clinical Features:

• Photophobia: Increased sensitivity to light.
• Eye Pain: Discomfort or pain in the eye.
• Eye Redness: Redness of the eye, indicating inflammation.
• Decreased Vision: Reduced visual acuity or clarity.
• Lacrimation: Increased tear production, usually without mucopurulent discharge.
• Circumcorneal Congestion: Congestion or redness around the cornea, also known as ciliary congestion.
• Keratic Precipitates (KP): Fine, grey deposits of protein at the back of the cornea. In non-granulomatous inflammation, these are associated with conditions such as sarcoidosis in granulomatous inflammation.

Types of Keratic Precipitates (KPs) and Associated Signs in Uveitis

• Mutton-Fat KPs: These are observed in granulomatous uveitis and are made up of macrophages, lymphocytes, and plasma cells that have transformed into epithelioid cells. Their greasy appearance gives them the name "Mutton-Fat" KPs.
• Medium White and Small KPs: These KPs are sharply defined and range in color from white to beige. They are seen in non-granulomatous uveitis and primarily consist of lymphocytes.
• Pigmented KPs: These occur when KPs uptake pigment, indicating a chronic inflammatory process that has been ongoing for a long time.
• Stringy Keratic Precipitates: These are characterized by fine, thin lines on the endothelial surface, creating a mesh-like appearance. They are composed of precipitated fibrin rather than cellular deposits.
• Red Keratic Precipitates: These are comprised of red blood cells and are associated with hyphema, a condition more commonly seen in viral uveitis, particularly herpetic uveitis.
• Iris Nodules:Indicative of granulomatous inflammation, these include:
  • Koeppe Nodules: Located at the pupillary border.
  • Busacca Nodules: Found at the base of the iris.
• Aqueous Cells: These inflammatory cells present in the aqueous humor signify active inflammation.
• Aqueous Flare: This condition results from protein leakage into the anterior chamber from the iris capillaries.
• Constricted Pupil:. small (miotic) pupil is a characteristic feature of uveitis. In anterior uveitis, the pupil becomes small and reacts slowly due to factors such as iris swelling, cell infiltration, and toxic effects on nerve endings. The sphincter muscle's compactness exerts a stronger effect than the dilator muscle, leading to pupil constriction. If permanent synechiae develop, the pupil may appear irregular, especially when dilated, resulting in a "festooned-shaped pupil."
• In Contrast: In acute angle-closure glaucoma, the pupil is vertically oval and dilated.
• Posterior Synechiae: This condition presents as an irregular, festooned-shaped pupil and can lead to seclusio pupillae (360° posterior synechiae), also known as ring synechiae. This can result in iris bombe and peripheral anterior synechiae (PAS), causing angle-closure glaucoma. Eventually, it may progress to occlusio pupillae, where fibrous tissue completely covers the pupillary space.
• Inflammatory Cells in Anterior Vitreous: The presence of inflammatory cells in the anterior vitreous indicates inflammation within the vitreous cavity.

Treatment of Anterior Uveitis

• Topical mydriatics: These medications are used to relax the ciliary muscles and prevent the formation of posterior synechiae, which are adhesions that can occur in the eye.
• Topical steroids: These are applied to reduce inflammation in cases of uveitis.
• Increased intraocular pressure: When uveitis leads to higher intraocular pressure, medications like latanoprost and pilocarpine should be avoided, as they can worsen inflammation.
• Cytotoxic drugs: In severe cases where patients do not respond to steroids, cytotoxic drugs may be necessary.
• Indications for Treatment:
• Behcet’s disease:. condition that can lead to uveitis.
• Sympathetic uveitis: This is a relative indication for treatment.
• Intermediate uveitis:. rare indication for treatment.
• Serpiginous choroiditis:. condition that may require treatment.
• Immunomodulators: Such as cyclosporin: These may be used in treatment.

Intermediate Uveitis, Pars Planitis, or Chronic Cyclitis

Intermediate Uveitis, also known as Pars Planitis or Chronic Cyclitis, is a type of chronic intraocular inflammation that is usually idiopathic and affects young adults. This condition typically develops insidiously and can lead to several visual symptoms.

• Blurred vision
• Floaters may gradually increase
• Visual acuity may decrease, especially if cystoid macular edema (CME) is present              

Differential Diagnosis of Snow-Banking

• Sarcoidosis
• Candidiasis
• Multiple sclerosis
• Ocular toxocariasis

Treatment:

• Step 1. Periocular steroid injections, particularly subtenon injections of triamcinolone acetate.
• Step 2. Administration of systemic steroids and cytotoxic medications.
• Step 3. Cryotherapy targeting the vitreous base to address retinal issues and manage the inflammatory membrane associated with snow banking.
• Step 4. Vitrectomy to alleviate inflammation and enhance vision by removing hazy media.

Posterior Uveitis

• Posterior uveitis involves inflammation of the choroid and other related structures such as the vitreous, optic disc, macula, peripheral retina, and retinal veins.
• Choroiditis. Characterized by the presence of yellowish round lesions in the choroid.
• Vitritis. Inflammation of the vitreous body.
• Cystoid macular edema. Swelling of the macula due to fluid accumulation.
• Papillitis. Inflammation of the optic disc.
• Retinal edema. Swelling of the retina, which may be associated with papilledema (swelling of the optic disc).
• Necrotic retinitis. Seen in cases of cytomegalovirus (CMV) infection, characterized by retinal tissue death.
• Periphlebitis. Inflammation of the retinal veins.

Treatment of Posterior Uveitis

• Periocular subtenon injections of steroids (Triamcinolone acetate).
• Systemic steroids.
• Rarely, cytotoxic drugs as mentioned above.

Complications of Uveitis

Uveitis can lead to various complications affecting different parts of the eye.

A. Corneal Complications:

• Sclerosing Keratouveitis
• Corneal Edema
• Bullous Keratopathy
• Disciform Keratitis
• Descemetocoele
• Pannus
• Band-shaped Keratopathy

B. Iris Complications: 

• Synechiae
• Atrophy
• Rubeosis

C. Lens Complications:

• Secondary cataract.

D. Globe Complications:

Glaucoma

• Cyclitic Membrane

Pthisis Bulbi: This condition involves the shrinkage of the eyeball, where all three layers of the eyeball are visible. This contrasts with atrophic bulbi, where the layers cannot be distinguished.

E. Posterior Segment Complications:

• Cystoid Macular Edema (CME): Caused by the release of prostaglandins during inflammation.
• Retinal Detachment: Can occur in various forms of uveitis, including anterior uveitis in specific cases.
• Optic Nerve Head Edema
• Macular Hole
• Cyclitic Membrane Formation: Leading to cilio-choroidal detachment and hypotony.
• Choroidal Neovascular Membrane

Causes of Anterior Uveitis

• Idiopathic anterior uveitis.
• Sero-negative arthropathies (including rheumatoid arthritis ).
• Reiter’s syndrome.
• Ankylosing spondylitis.
• Psoriatic arthritis.
• Juvenile Rheumatoid Arthritis (JRA).
• Inflammatory bowel disease.
• Fuchs' heterochromic cyclitis.
• Viral (HSV, HZO) keratouveitis.
• Posner-Schlossman syndrome.

Causes of Panuveitis

• Sympathetic ophthalmitis.
• Syphilis.
• Vogt Koyanagi-Harada syndrome.
• Tuberculosis.
• Toxoplasmosis.

Causes of Posterior Uveitis

• Idiopathic posterior uveitis.
• CMV retinitis.
• Toxocariasis.
• Presumed ocular histoplasmosis syndrome.
• Acute retinal necrosis.
• White dot syndromes.
• Eales disease.

Causes of Intermediate Uveitis

• Lyme disease.

Causes of Granulomatous Uveitis

• Sympathetic ophthalmia.
• Lens-induced uveitis.
• VKH syndrome.
• Tuberculosis.
• Leprosy.

Investigations

Haematological Tests/Serological Tests:

• TLC, DLC, ESR: These tests are conducted to detect infections and tumors.
• An increase in neutrophils in the Differential Leucocyte Count (DLC) suggests the presence of bacterial infections or immune complex disorders.
• Eosinophils: An increase in eosinophils indicates parasitic infections.
• Lymphocytes: Elevated lymphocyte levels are associated with viral, fungal infections, or hypersensitivity reactions.
• Macrophages: Increased macrophages are linked to conditions like sympathetic ophthalmia or phacoanaphylactic reactions. Tumour cells. The presence of tumour cells in the samples indicates masquerade syndrome.
• Urine analysis: This test checks for pus cells and calcium levels in the urine to rule out conditions like Reiter’s syndrome and syphilis.
• VDRL and FTA-ABS: These tests are used to detect syphilis.
• ACE titres: Elevated serum ACE levels are indicative of sarcoidosis.
• ELISA and Western Blot: These tests are used to rule out AIDS.
• Immunofluorescent tests, ELISA, Indirect Haemagglutination tests, and PCR. These tests are conducted to exclude infections like toxoplasmosis, toxocariasis, and Lyme disease.
• ANA: This test is used to check for Juvenile Rheumatoid Arthritis (JRA) and other connective tissue disorders.

Skin Tests: All tests are based on type IV hypersensitivity reactions.

• Lepromin test.
• Histoplasmosis skin test.

Imaging Techniques:

• X-ray chest: Can reveal TB, Sarcoidosis, and old calcified lesions in the lungs and spleen associated with POHS (Posterior Uveitis).
• X-ray sacroiliac joint: Used for ankylosing joint assessment.
• X-rays of affected joints: Conducted to look for signs of arthritis.
• Skull X-ray. Detects calcification in cases of congenital toxoplasmosis.
• Gallium-67 scan: Utilised for diagnosing sarcoidosis.

Ultrasound (USG)

• In cases of hazy ocular media, particularly in suspected toxocariasis, USG is necessary to rule out other causes of leukocoria.

Aqueous Tap or Vitreous Biopsy:

•  This procedure involves analyzing samples from the eye to check for signs of infection or inflammation. 
•  Cytology and histology are used to examine the cells and tissue structure in the samples. 
•  Antibody testing helps identify specific infections, such as endophthalmitis or toxoplasmosis. 

Biopsies:

• Conjunctival: This is done to check for conditions like Sarcoidosis, Tuberculosis, Leprosy, and Syphilis.
• Lacrimal Gland: Biopsies of the lacrimal gland are often associated with Sarcoidosis.
• Mucosal (Buccal):. mucosal biopsy from the buccal area is linked to Behcet’s disease.
• Vitreous: Vitreous biopsies are relevant for conditions like Endophthalmitis and Acute Retinal Necrosis.
• Syphilitic Chancre: This refers to a specific type of sore associated with Syphilis.

Fluorescein Angiography or Indocyanine Green Angiography:

• These imaging techniques are used in cases of anterior or intermediate uveitis with unexplained vision loss to rule out Cystoid Macular Edema (CME).
• They are also applicable in posterior uveitis, Vogt-Koyanagi-Harada (VKH) disease, and Sympathetic Ophthalmia (SO).

ISpecial Tests:

• Audiometry: This test is used in cases of Vogt-Koyanagi-Harada (VKH) disease to assess hearing function.
• Lumbar Puncture:. lumbar puncture may be performed in suspected cases of intraocular lymphomas and VKH disease to analyze cerebrospinal fluid.
• Gallium Scan: This imaging test can be used in various conditions to detect abnormal gallium uptake in tissues.

Systemic Associations of Uveitis

Uveitis Associated With Arthritis

Ankylosing Spondylitis:

• A type of inflammatory arthritis that primarily affects the spine, leading to stiffness and pain.
• Strongly associated with the genetic marker HLA-B27.
• Causes acute and recurrent episodes of non-granulomatous iritis, which is inflammation of the iris.
• Rheumatoid factor (RA factor) is typically negative in this condition.

Reiter’s Syndrome:

• Characterized by a triad of symptoms:
• Urethritis (inflammation of the urethra).
• Conjunctivitis (inflammation of the conjunctiva).
• Associated with the genetic marker HLA-B27.

Ocular Features:

• Bilateral mucopurulent conjunctivitis.
• Acute iritis.
• Keratitis (inflammation of the cornea).

Psoriatic Arthritis:

• Associated with psoriasis, which presents as red, scaly patches on the skin.
• Psoriatic arthritis may lead to secondary Sjögren’s syndrome, an autoimmune condition that affects moisture-producing glands.

Juvenile Chronic Arthritis (JCA):

• Idiopathic inflammatory arthritis occurring in children under 16, lasting at least three months.

Types of JCA include:

• Systemic onset.
• Polyarticular (involving more than 5 joints).
• Pauciarticular (fewer than 5 joints).
• JCA is a sero-negative arthritis, meaning rheumatoid factor is absent.
• Pauciarticular arthritis is specifically linked with uveitis.

Anterior Uveitis:

• Chronic condition, non-granulomatous in nature, and usually bilateral (70% of cases).
• Often asymptomatic and detected during routine slit lamp examinations.
• During examination, the eye may appear white with no redness, even in severe cases of uveitis, a phenomenon known as "White Uveitis."
• Keratic precipitates (KPs) can range from small to medium size.
• Hypopyon (accumulation of pus in the anterior chamber) is rare.
• Posterior synechiae (adhesions between the iris and the lens) are common in long-standing cases of anterior uveitis.

Complicated Cataract:

• Band Keratopathy
• Extensive Posterior Synechiae
• Secondary Glaucoma
• Topical Steroids, Periocular Injection of Steroids, Systemic Steroids

Sarcoidosis

• Sarcoidosis is a condition where small clusters of inflammatory cells, called non-caseating granulomata, form in various organs, especially the lungs. The exact cause of this condition is not known.
• In the eye, sarcoidosis leads to a type of inflammation known as granulomatous panuveitis, which affects multiple parts of the eye.
• Sarcoid plaques and sarcoid granulomata can appear on the eyelids.
• The anterior segment of the eye, including the conjunctiva, episclera, and sclera, may be involved.
• Keratoconjunctivitis sicca (KCS) can occur due to the involvement of the lacrimal gland, leading to dry eyes.
• Anterior uveitis is characterized by chronic granulomatous inflammation of the iris and ciliary body.
• Diffuse vitritis refers to inflammation of the vitreous gel inside the eye.
• Snowball opacities in the vitreous are a specific finding in this condition.
• Fundus changesin sarcoidosis may include:
  • Periphlebitis, where advanced vascular sheathing leads to a phenomenon known as candle-wax drippings.
  • The presence of retinal granulomata.
  • Pre-retinal nodules, also referred to as Lander’s sign.
  • Retinal haemorrhages, which can occur in acute sarcoid retinopathy.
  • Choroidal granulomata.
• Optic nerve lesionsin sarcoidosis may include:
  • Disc granuloma, where granulomatous inflammation occurs at the optic disc.
  • Neovascularization, the growth of new blood vessels.
  • Papilloedema, swelling of the optic disc.
  • Optic atrophy, the degeneration of optic nerve fibers.

Behcet's Disease
Behcet's Disease is a complex condition that primarily affects young men and involves inflammation of blood vessels due to immune responses. It impacts various systems in the body.

• Oral Ulceration: Causes painful sores in the mouth.
• Recurrent Genital Ulceration: Leads to repeated sores in the genital area.
• Skin Lesions: Results in various skin problems.
• Eye Involvement: Includes serious eye issues that can affect vision.
• Positive Pathergy Test: Indicates a reaction to minor skin injuries.

HLA-B51 Associated:

• Recurring Eye Inflammation: Involves inflammation in both eyes, affecting either the front (anterior) or back (posterior) part of the eye.
• Anterior Segment: Sudden flare-ups of iridocyclitis may occur, leading to temporary fluid accumulation. This can result in:
• Swelling of the Retina: Fluid leakage can cause swelling of the retina.
• Cystoid Macular Edema (CME): Accumulation of fluid in the macula, a part of the retina.
• Swelling of the Optic Nerve: Inflammation and swelling of the optic nerve.
• Retinitis: Characterized by white, necrotic areas in the inner retina, which may lead to:
• Internal Bleeding in the Retina: Bleeding within the retinal tissue.
• Retinal Tissue Loss: Destruction or loss of retinal tissue.

Vogt-Koyanagi-Harada Syndrome:
Vogt-Koyanagi-Harada Syndrome is a rare, idiopathic multisystem disorder that predominantly affects individuals with darker pigmentation. It is associated with the genetic marker HLA-DR4.

Skin and Hair Changes:

• Alopecia: Hair loss, which can be partial or complete.
• Poliosis: Whiteness or loss of pigment in hair, often seen as a white patch of hair.
• Vitiligo: Skin depigmentation, also known as Sugiura's sign, where white patches appear on the skin due to loss of melanocytes.

Neurological Features:

• Irritation: Symptoms indicating irritation of the nervous system.
• Encephalopathy:. broad term for brain disease, damage, or malfunction.
• Auditory Symptoms: Including tinnitus (ringing in the ears), vertigo (dizziness), and deafness.
• Cerebrospinal Fluid Analysis: Shows lymphocytosis, an increased number of lymphocytes in the cerebrospinal fluid.
• Chronic Granulomatous Iridocyclitis: Inflammation of the iris and ciliary body that is persistent and granulomatous in nature.

Posterior Segment:

• Multifocal Choroiditis: Inflammation of the choroid layer of the eye at multiple sites.
• Multifocal Detachment of Sensory Retina: Detachment of the sensory retina at multiple locations, which can lead to vision problems.

Ocular Complications in AIDS:

• In patients with AIDS, ocular complications are observed in 75% of cases.

Retinal Microangiopathy:

• Most Common Ocular Manifestation: Retinal microangiopathy is the most frequent ocular manifestation in AIDS.
• Typically Non-Infectious: This condition is usually non-infectious.
• Characterised by:Cotton Wool Spots: Soft white patches on the retina caused by the accumulation of axoplasmic material. These spots resolve on their own over time. Haemorrhages: Bleeding within the retina. Microaneurysms: Small bulges in the blood vessels of the retina.

Pathogenesis:

• Immune Complex Deposition: The condition may be due to the deposition of immune complexes in the retinal vasculature.
• HIV Infection of Retinal Vascular Endothelium: The retinal microangiopathy may also result from the infection of retinal vascular endothelial cells by HIV.

Opportunistic Infections:

• CMV Retinitis: This is the most common secondary infection in AIDS patients, caused by the reactivation of cytomegalovirus in immunocompromised individuals.
• Central Retinitis:
  • Characterised by a dense, white, well-defined area of retinal necrosis along the vascular arcades, accompanied by retinal haemorrhages in or near the necrotic area. This condition is referred to as “Sauce and Cheese Retinopathy.”
• Peripheral Retinitis:
  • Similar to central retinitis but with less distinct borders.
  • The infection spreads slowly along the vascular arcades and may lead to retinal atrophy, optic atrophy, and retinal detachment.

Treatment:

• I/V Gangcyclovir: Intravenous administration of Gangcyclovir for the treatment of CMV retinitis.
• I/V Foscarnet: Intravenous Foscarnet as an alternative treatment for CMV retinitis.
• Intravitreal Gangcyclovir Implants: Surgical implantation of Gangcyclovir implants in the vitreous cavity for sustained release and treatment of CMV retinitis.

Pneumocystis Jiroveci Choroiditis

• Pneumocystis jirovecii is a protozoan parasite that primarily impacts individuals with AIDS, causing serious health complications.
• Common indicators of choroiditis are flat, yellow, round lesions located behind the equator of the eye.
• Treatment alternatives include:
  • Intravenous Trimethoprim combined with Sulfamethoxazole.
  • Parenteral Pentamidine.

Toxoplasma Retinochoroiditis

Fungal Infections: Cryptococcus neoformans Choroiditis:

• This is the most common fungal infection linked to AIDS.

Asymptomatic Creamy Choroidal Lesions:

These lesions are not linked with vitritis and are characterized by their creamy appearance.

Optic Nerve Involvement:

• When the optic nerve is involved, it can lead to either disc swelling or retrobulbar neuritis.
• This condition is typically associated with meningitis.

Histoplasma Capsulatum:

• Histoplasma Capsulatum is a rare fungal infection commonly found in patients with AIDS.
• This infection can lead to POHS, which stands for Presumed Ocular Histoplasmosis.

Clinical Features of POHS:

• The clinical features of POHS include a triad of symptoms:
• Multiple atrophic choroidal spots, referred to as histospots.
• Peripapillary atrophy, which is the thinning of the tissue around the optic nerve head.
• Haemorrhagic disciform maculopathy, characterized by bleeding in the macula area of the retina.

Candidiasis:

• Candidiasis is another fungal infection that can affect the posterior segment of the eye.

Varicella-Zoster Retinitis:

• Varicella-Zoster Retinitis leads to acute retinal necrosis (ARN). While CMV and HSV cause ARN in younger individuals, herpes zoster ophthalmicus (HZO) occurs in adults.

Large Cell Intraocular Lymphoma:

• Toxoplasmosis is a parasitic infection caused by Toxoplasma gondii, which primarily infects cats (the main host) and can also affect humans and mice (secondary hosts). Infection in humans often occurs during fetal development, but it can reactivate later in life due to the rupture of cysts in the eye, particularly in old scars.

Symptoms of Toxoplasmosis

• Iridocyclitis: Can be either granulomatous (involving inflammatory cells) or non-granulomatous.
• Posterior Uveitis:
  • Focal Superficial Necrotising Retinochoroiditis: Characterized by the "Headlight in Fog Appearance."
  • Deep Retinitis: Affects the inner layers of the retina.
  • Granuloma Formation: Development of granulomas in the eye.
  • Old Choroidal Lesions: Resulting from toxoplasmosis, these appear as punched-out spots with pigmented edges.

Treatment for Toxoplasmosis:

• Systemic Steroids: Administered via subtenon injections in patients with compromised immune systems.
• Clindamycin: 300 mg four times a day.
• Sulphonamide Therapy: Part of the treatment regimen.
• Pyrimethamine: Used in treatment.
• Co-trimoxazole: Another medication used.

Adjunctive Therapy

• Laser Photocoagulation: Used to contain the spread of infection by surrounding the active lesion.
• Cryotherapy: For treating peripheral lesions when laser treatment is not feasible.
• Vitrectomy: Considered in cases of severe opacities in the eye.

Syphilis
(a) Anterior Segment:

• Madarosis: This refers to the loss of eyelashes and eyebrows, both of which are considered forms of madarosis.
• Primary chancre of the conjunctiva.
• Scleritis.
• Interstitial keratitis affecting the stroma of the cornea.
• Acute granulomatous or non-granulomatous uveitis.

(b) Posterior Segment:

• Multifocal chorioretinitis: Also known as "Salt and pepper fundus" or "Pseudo-Retinitis Pigmentosa."
• Salt and Pepper Fundus: This condition is characterized by the dispersion of pigment in the retina, creating an appearance reminiscent of salt and pepper.
• Differential Diagnoses of Salt and Pepper Fundus:
  • Rubella.
  • Retinitis pigmentosa sine pigmento.
  • Carriers of albinism.
  • Refsum’s disease, a type of Phytanic acid storage disorder.
  • Leber’s congenital amaurosis.
• Unifocal choroiditis: This is a less common condition that can occur in the context of syphilis.
• Juxtapapillary choroiditis: Inflammation near the optic disc.
• Central choroiditis: Inflammation at the macula, also referred to as a macular patch.
• Other causes of macular patch:
  • Central choroiditis due to toxoplasmosis.
  • Atrophic choroidal spots from histoplasmosis, known as histiospots.
  • Pathological myopia.
  • Trauma.
  • Macular coloboma.
• Neuroretinitis: This condition involves retinal and optic disc swelling, along with peripapillary cotton wool spots and flame-shaped haemorrhages.

(c) Neuro-Ophthalmic Features:

• Argyll-Robertson pupil: This pupil reaction is characterized by no response to light, but the near reflex is intact.
• Optic nerve lesions:
  • Retrobulbar neuritis: Inflammation of the optic nerve behind the globe.
  • Papilloedema: Swelling of the optic disc due to raised intracranial pressure.
  • Perioptic neuritis: Inflammation of the optic nerve coverings, often associated with syphilitic meningitis.
  • Ocular motor palsy: Involvement of the 3rd and 6th cranial nerves.
  • Visual field defects: These can occur due to gummatous lesions affecting the brain.
• Treatment: For syphilis, the standard treatment involves administering 12–24 million units of aqueous penicillin intravenously for 10 days, followed by 2.4 million units intramuscularly for 3 weeks. Alternatively, oral tetracycline and oral erythromycin may also be used.

External Lesions: Syphilis can affect any ocular and periocular structures, including the eyelids, conjunctiva, cornea, sclera, and orbit.

Uveitis: In tuberculosis-related uveitis, specific findings are often absent, and clinical symptoms can vary widely.

Chronic iridocyclitis: This is the most common feature associated with tuberculosis-related uveitis and is usually granulomatous in nature.

• Choroiditis: This can be focal or multifocal.
• Retinal vasculitis: This condition is characterized by moderate vitritis, severe ischaemic periphlebitis, and peripheral capillary closure leading to neovascularisation.

Antitubercular therapy (ATT) drugs are commonly used in the treatment of tuberculosis-related uveitis.

Leprosy:

• Madarosis: This refers to the loss of eyebrows and eyelashes, which can occur in leprosy.
• Trichiasis: This condition involves the abnormal growth of eyelashes, which can cause irritation to the eye.
• Episcleritis and scleritis: Inflammation of the episclera and sclera, respectively, can occur in leprosy.
• Facial palsy: This can lead to lagophthalmos, a condition where the eyelid cannot close completely.
• Granuloma on the cornea: Granulomatous lesions can develop on the cornea in leprosy.
• Leperoma on the cornea: Similar to granulomas, leperomas are specific types of lesions that can occur on the cornea in leprosy.
• Interstitial keratitis: Inflammation of the corneal stroma can occur in leprosy.
• Granulomatous uveitis: This type of uveitis is characterized by the presence of granulomatous inflammation and can occur in leprosy.
• Optic neuritis: Inflammation of the optic nerve can occur in leprosy.
• Iris pearls and iris atrophy: These findings can be observed in chronic uveitis associated with leprosy.

Fuchs’ Uveitis Syndrome or Fuchs’ Heterochromic Cyclitis (FUS):

• Overview: Fuchs’ Uveitis Syndrome is a gradual, non-granulomatous anterior uveitis that typically affects one eye in middle-aged patients.
• Symptoms: Patients may experience uniocular blurring of vision due to cataract formation.
• Keratic Precipitates: These are small, star-shaped, grey-coloured deposits scattered in the cornea. They do not merge or become pigmented, and feathery fibrin filaments may sometimes appear between the keratic precipitates.
• Aqueous Humour: The aqueous humour may show faint flare, few cells, and no posterior synechiae.
• Iris Changes: Iris stromal atrophy may be observed, possibly linked with patchy atrophy of the posterior pigment layer of the iris. Heterochromia iridis may also be present. Koeppes nodules and rubeosis iridis may be seen in some cases.
• Pupil and Intraocular Pressure: The pupil may be enlarged due to atrophy of the iris sphincter. Glaucoma, typically of the open-angle type, may develop due to trabecular sclerosis.
• Treatment: Topical steroids and mydriatics are usually not needed, as no synechiae develop. Regular follow-up every six months is recommended to check for glaucoma.

Sympathetic Ophthalmitis

• Sympathetic Ophthalmitis is a very rare condition that causes bilateral, granulomatous, non-suppurative panuveitis.
• It typically occurs after accidental penetrating trauma to the eye.
• The condition involves both eyes, with the injured eye referred to as the exciting eye and the unaffected eye as the sympathising eye.
• Approximately 65% of cases arise between 2 weeks and 3 months post-injury, and 90% manifest within the first year.
• Prodromal symptoms in the sympathising eye may include:
  • Blurring of vision due to loss of accommodation, which is often the first symptom.
  • Photophobia.
• Anterior segment signs of sympathetic ophthalmia include:
  • Red and irritable eye.
  • Earliest sign: Retrolental flare, indicating inflammation in the ciliary body.
  • Koeppe nodules.
  • Mutton-fat KPs.
  • Posterior synechiae.
  • Dalen-Fuch’s Nodules, which are small, deep, yellow-white spots scattered in the fundus, consisting of epithelioid cells between retinal pigment epithelium and Bruch’s membrane.
  • Optic nerve head oedema.
  • Sub-retinal oedema.
  • Pthisis bulbi.
• Treatment for sympathetic ophthalmia includes:
  • Vigorous steroid therapy via all available routes.
  • Immunosuppressive therapy with Chlorambucil, Cyclophosphamide, or Cyclosporin in severe steroid-resistant cases.
  • Enucleation, not evisceration, within 2 weeks of injury to prevent sympathetic uveitis. Evisceration may increase the risk of sympathetic ophthalmia if uveal tissue remains.

River Blindness (Onchocerciasis)

• River Blindness, also known as Onchocerciasis, is caused by infection with the nematode Onchocerca volvulus.
• This disease is endemic in Africa, Central America, and South America.
• The vector responsible for spreading the infection is the blackfly.
• Microfilariae reproduce in nodules within the body and spread, causing local inflammation. The exact route of entry into the eye is not well understood.
• Signs of anterior uveitis in Onchocerciasis include:
  • Non-granulomatous anterior uveitis, which is often the earliest sign.
  • The presence of a small, white wriggling worm in the anterior chamber.
• Sclerosing keratitis is the major cause of blindness in this condition.
• Chorioretinitis leads to chronic, non-granulomatous chorioretinitis, resulting in extensive retinal atrophy and scarring, with the macula typically spared.
• Visual field defects and night blindness may not correlate with the observed changes in the fundus.
• Ivermectin is administered only to individuals at high risk of blindness due to the potential for severe systemic inflammation known as MAZZOTI’S REACTION, which can be life-threatening.
• The control of onchocerciasis is part of the Vision 2020 programme.

Ophthalmia Nodosum

Ophthalmia Nodosum is an extremely severe type of granulomatous irido-cyclitis that occurs when caterpillar hairs enter the eye. This condition leads to the formation of a large nodule on the iris, which is how it got its name.

Posner-Schlossman Syndrome

Posner-Schlossman Syndrome, also known as glaucomatocyclitic crisis or hypertensive uveitis, is characterized by:

• Recurrent episodes of mild anterior uveitis
• Potential development of secondary open-angle glaucoma
• Severely elevated intraocular pressure, typically ranging from 40 mm Hg to 60 mm Hg
• Few signs of uveitis, such as keratic precipitates (KPs)

This condition can be mistakenly diagnosed as acute angle-closure glaucoma.

The primary goal of treatment is to manage uveitis, which can help reduce intraocular pressure. Treatment options include:

• Atropine therapy combined with medical reduction of intraocular pressure
• Topical steroids, although their role is uncertain as they may increase intraocular pressure; mild steroids might be necessary to control uveitis

Therefore, the choice of treatment should be tailored to the specific clinical situation and adhere to current guidelines for patients with uveitis and elevated intraocular pressure.

Heterochromia Iridis: (D/D)

Heterochromia iridis refers to a condition where the irises are of different colors. This condition can be present at birth or develop later in life, and it has various underlying causes.

Congenital Causes:

• Waardenburg’s Syndrome:. genetic disorder that can cause changes in pigmentation, including heterochromia.
• Horner’s Syndrome:. condition that affects the nerves supplying the eye and can lead to differences in iris color.
• Nevus of Ota:. localized pigmentation disorder that can result in heterochromia.
• Congenital Ocular Melanocytosis:. condition present at birth characterized by increased pigment in the eye, which can lead to heterochromia.

Acquired Causes:

• Chronic Iritis: Inflammation of the iris that can lead to changes in iris color.
• Iris Nevus or Melanoma: Abnormal growths in the iris that can affect its color.
• Siderosis:. condition caused by excess iron in the eye, leading to changes in iris color.
• Topical Latanoprost:. medication used to treat glaucoma that can cause changes in iris pigmentation.

Ocular Features of Ulcerative Colitis

Ulcerative colitis, a type of inflammatory bowel disease, is often associated with certain ocular (eye) features. The most commonly reported ocular sign in patients with ulcerative colitis is recurrent anterior uveitis, also known as iritis. This condition involves inflammation of the front part of the uvea, which includes the iris. Anterior uveitis can occur in one eye (unilateral) or in both eyes (bilateral).

• In some cases, patients with ulcerative colitis may also develop ankylosing spondylitis, which is a type of inflammatory arthritis that primarily affects the spine and can be associated with eye conditions like uveitis.

Ocular Symptoms in Crohn’s Disease

• Anterior uveitis
• Scleritis
• Extraocular muscle paresis
• Lid edema
• Retinal vasculitis
• Peripheral corneal infiltrates

Management of Uveitis in Inflammatory Bowel Disease

• Oral NSAIDs
• Immunomodulator therapy
• Azathioprine

Ocular Manifestations of Whipple’s Disease

• Supranuclear ophthalmoplegia
• Antibiotic therapy

White Dot Syndromes

• This term encompasses various uveitic conditions characterized by the presence of multiple white dots in the retinal pigment epithelium and/or choroid.
• These white dots are microgranulomas composed of lymphocytes and macrophages, with T-lymphocytes being the predominant cell type.

Causes of White Dot Syndromes

White dot syndromes can be caused by various factors, including inflammatory, degenerative, neoplastic, traumatic, and medications or systemic causes.

Inflammatory Causes:

• Presumed Ocular Histoplasmosis Syndrome (POHS):. condition believed to result from past infection with Histoplasma, leading to scarring and inflammation in the eye.
• Multiple Evanescent White Dot Syndrome (MEWDS): Characterized by the sudden appearance of white dots in the retinal pigment epithelium, often resolving spontaneously.
• Multifocal Choroiditis: Involves inflammation of multiple areas in the choroid, leading to vision problems.
• Sympathetic Ophthalmitis:. rare, bilateral inflammatory condition following trauma to one eye, affecting both eyes.
• Vogt-Koyanagi-Harada (VKH) Syndrome: An autoimmune disorder affecting the eyes, skin, and other organs, leading to inflammation.
• HIV-related Retinal Complications: Inflammatory changes in the retina associated with HIV infection.
• Serpiginous Choroidopathy:. progressive inflammatory condition affecting the choroid, leading to vision loss.

Degenerative Causes:

• Stargardt’s Disease:. genetic disorder causing progressive degeneration of the macula, leading to vision loss.
• Retinitis Punctata Albescens:. retinal dystrophy characterized by the accumulation of white dots in the retina.
• Drusen: Yellow-white accumulations of extracellular material in the retinal pigment epithelium, associated with age-related macular degeneration.

Neoplastic Causes:

• Leukemic Retinopathy: Retinal changes associated with leukemia, including hemorrhages and exudates.
• Metastatic Tumors: Spread of cancerous cells to the retina from other parts of the body.
• Large Cell Lymphoma:. type of Non-Hodgkin’s Lymphoma affecting the retina.

Traumatic Causes:Purtscher’s Retinopathy: Retinal changes following severe trauma, such as chest injuries, leading to vision loss.

• Medication and Systemic Causes:
  • Chloroquine and Tamoxifen: Medications associated with retinal toxicity and white dot syndromes.
  • Photocoagulation Spots: Retinal changes following laser photocoagulation treatment.