Disorders of the Cornea, Sclera and Orbit

Cornea is anterior part of fibrous cover. Is a part of dioptric apparatus of the eye.

In normal:
avascular
sensitive
transparent
smooth
glassy
spherical
resplendent

Investigation of Corneal Disease
Anamnesis
Clinical examination
Biomicroscopy
Pachometry
Keratometry
Keratoscopy
Laboratory investigations

Keratitis – inflammation of the cornea
Keratitis (objective signs)
=
Corneal oedema
+
Cellular infiltration
+
Ciliary congestion
keratitis (adenovirus)

Corneal syndrome
photophobia
lacrimation
blepharospasm
a sensation of a foreign body present behind the eyelids
pain

Classification
1. Exogenous keratitis
Corneal erosions
Traumatic keratitis
Bacterial keratitis
Keratitis, caused by disease of conjunctiva, eyelids, meibomite glands.
Fungal keratitis
Corneal ulcer
2. Endogenous keratitis
Infectious (tuberculous, viral, rheumatic, toxicoallergic and others)
Neuroparalytic keratitis
Keratitis because of avitaminosis
3. Keratitis of unclear etiology (recurrent erosion, rosacea keratitis and other)

Bacterial keratitis – often develop in chronic inflammatory diseases of conjunctiva and lacrimal ducts, as well as in the trauma of the cornea.
Predisposing Condition to Bacterial Keratitis:
1/ Contact Lens Wear
2/ Nonsurgical Trauma
Corneal abrasion or wound
Corneal foreign body
Toxic medications (e.g., anesthetic abuse, idoxuridine)
3/ Surgical Trauma
4/ Corneal Injury Caused by Lid Dysfunction
Trichiasis
Lagophthalmus
5/ Corneal, Conjunctival, or Lacrimal Dysfunction
Bullous keratopathy
Neurotrophic cornea
Stevens-Johnson syndrome
Tear insufficiency
Mucin insufficiency

Epithelial punctate keratitis
Keratitis with necrosis
Regressive keratitis
corneal ulcer, iritis, hypolion in keratomycosis

Herpes Simplex Keratitis
Primary ocular infection typically occurs in children between the ages of 6 months and 5 years. Is more frequently accompanied by anterior uveitis and keratic precipitates, early vascularization, hypoaesthesia, photophobia, blepharospasm, lacrimation.

Recurrent infection:
Epithelial punctate keratitis
Dendritic keratitis
Metaherpetic keratitis
Disciform keratitis
Corneal syndrome, pericorneal hyperemia, hypoaesthesia.
The lesion is composed of clear vesicles in the epithelium arranged in a dendritic or stellate pattern

additional investigations of patients with keratitis
review roentgenography of the additional nasal sinus and organs of the chest
consultations of the otorhinolaryngologist and stomatologist (sometimes of phthisiatrician and dermatovenerologist)
results of additional methods of investigation: clinical and laboratory (detailed blood count, Wassermann reaction, Mantoux reactions, focal test with tuberculin, toxoplasmin and others).

Laboratory diagnosis
Herpeviral
Express-diagnosis-method of fluorescining antibodies – revealing of virus in the scrub of conjunctiva
Monoclonal immunofermental test-system
Finding of antiallergic antibodies in lacrimal fluid in the reaction of passive hemagglutination
Finding of lymphocytes to herpes in the reaction of blasttansformation and inhibition of leucocytes migration
Finding of IgA, IgG, IgM in lacrimal fluid and blood serum
Bacterial
Conjunctical smear in deep ulcers of the cornea - smear-print from the ulcer.
Scrub from ulcerous surface and margins of ulcer
Staining – with methylene blue and Gram’s staining
inoclulation of media with investigation of antibiotic sensitivity

The differential diagnosis of primary ocular infection includes:
1. Keratitis with lid lesions: zoster, chickenpox, molluscum contagiosum, and ulcerative blepharitis with keratitis due to staphylococcal infection
2. Keratitis without lid lesions: vaccinia, adenoviral infections (types 3, 7, and 8), chlamydial infections, and zoster

Parasitic Keratitis - Acanthamoeba
Slit lamp photograph of a 42 year old female patient with unilateral, red, painful eye with epithelial defect; Corneal sensitivity decreased.
Stromal ring infiltrate (1), fluorescein staining (2).
Corneal scrapings and PCR for VZV negative.
confocal microscopy in vitro

Keratomycoses
Risk factors: long treatment with antibiotics or coricosterois, microtraumas of the cornea, fungus skin diseases.
Greyish-white infiltrate with crumb-like friable surface and yellowish border appears on the place of corneal erosion, presence of hypopion is typical. Vascularization is insignificant.

Ulcer of cornea – inflammation of corneal membrane, accompanying with necrosis with formation of its tissue defect
Infectious –bacterial, herpeviral, fungal and parasitic infection of the eyes.
Noninfectious – ulcer of immune genesis, corneal xerosis, in absolute glaucoma
Risk factors:
conjunctivites,
dacriocystites,
Corneal xerosis,
traumas of the cornea,
foreign bodies of the cornea,
injuries by chemical, thermal, radiation, laser affection.
long wearing of contact lenses,
various operations on the cornea,
bullous keratopathia.

Organisms Commonly Isolated From Corneal Ulcers
Healthy Cornea Compromised Cornea* Pediatric
Staphylococcus Staphylococcus aureus Pseudomonas
Streptococcus Staphylococcus epidermidis Staphylococcus
Pseudomonas a-Hemolytic Streptococcus Fungi
Enterobacteriaceae b-Hemolytic Streptococcus
Moraxella Pseudomonas
Klebsiella Proteus
Corneal creeping ulcer with the thread of perforation

Stages of ulcerous process:
Stage of infiltration
Stage of infiltrate decay and formation of ulcer
Stage of facet – regression of ulcer, is characterized by clearance from necrotic residues of the fundus and margins of the ulcer and rapid growth of epithelium, that covers the fundus and margins of the cornea defects
Stage of the scar formation
Stage of outcome – maturation and thickness of connective-tissue scar

Mooren’s Ulcer
Corneal ulcer with neovascularization
Bacterial corneal ulcers
Perforation of corneal ulcer

Principles of Keratitis and Corneal Ulcers treatment
1. Specific therapy:
a) Antiviral (Zovirax, Aceclovir ointment 3% - 5 times a day or Lokferon 8000 МЕ/ml instillation 8 times a day for 5-7 days + systemic therapy)
b) Antibacterial
Local – moxifloxacin, Cefazolin, Tobramycin, Gentamicin 4-8 times a day, Erythromycin, Tetracyclin ointment 1% 3-4 times a day
Parabular – Tobramycin, Gentamicin, Cefazolin
Systemically - Maxavin, Erythromycin, Doxicyclini, Ceftriaxone
c) Antifungal (local suspension of ketoconazole, miconazole ointment 4 times a day + Nizoral 200mg 2 times daily)
d) Antiparasitic (topical propamidine, neomysin, clotrimazole)

2. Pathogenetic therapy
Antiinflammatory (Eye drops – only non-steroidal antiinflammatory: Naclof. Parabular or intravenous injection of dexamethazon (in severe course)
Antiallergic
Metabolic - taufon, actovegin, solcoseril, corneregel, vitamins
Hypotensive - in a case of the eye hypertesion or secondary glaucoma.
Mydriatic-cycloplegic drugs - instillation of 1.0% mydriacyl, tropicamid.
Physiotherapy, Criotherapy

Following arresting of inflammatory process a course of resolving therapy (fibrinolysin, lidase)
Penetrating keratoplasty indicated for visual rehabilitation in patients with sever corneal scarring. Lamellar keratoplasty has advantage over penetrating keratoplasty of reduced potential for corneal graft rejection.

Complications of keratitis:
limbal and scleral extension
corneal perforation
iridocyclitis
endophthalmitis
Panophthalmitis
Secondary glaucoma
Corneal scarring: nebula, macula, leucoma, kerectasia, anterior staphyloma

Sclera – is a part of fibrous coat of the eyeball
The sclera is composed of three layers:
the episclera
the sclera proper
the lamina fusca
The sclera is relatively poorly vascularized. Its blood supply is derived from the anterior and posterior ciliary arteries.

Episcleritis is a inflammatory disorder of the superficial layer of the sclera.
Is a common, benign, self-limiting and frequently recurrent disorder which typically affects young adults.
the episcleritis may be nodular or diffuse

Systemic diseases with episcleritis

• Sudden onset of FB sensation, discomfort, tearing ± photophobia. It may be recurrent.
• Red nodule arising from the episclera; can be moved separately from the sclera and conjunctiva; blanches with topical vasoconstrictor (phenylephrine 10%); does not stain with fluorescein; globe nontender
Spontaneous resolution occurs in 5–6 weeks.
Nodular Episcleritis

Diffuse episcleritis
Sudden onset of mild discomfort, tearing ± photophobia; may be recurrent.
Sectoral redness that blanches with topical vasoconstrictor (phenylephrine 10%); globe nontender; spontaneous resolution 1–2 weeks.

Episcleritis
Generally, the pain is not as severe as with scleritis.
Hyperemia of the episcleral tissues most often is localized but may involve the entire anterior segment.
The inflammatory process does not involve underlying sclera or intraocular tissue.

Treatment
If mild, no treatment is required.
Supportive: reassurance ± cold compresses.
Topical: consider lubricants ± NSAID (ketorolac 0.3% 3x/day). Although disease improves with topical steroids, there may be rebound inflammation on withdrawal.
Systemic: if severe or recurrent disease, consider oral NSAID (flurbiprofen 100 mg 3x/day for acute disease).

COMPLICATIONS
Involvement of other ocular structures is rare in patients with episcleritis.
The peripheral cornea can be left thinned or vascularized. Recurrent attacks of episcleritis over many years can result in some mild scleral thinning, which is of no consequence to the integrity of the eye.
The most frequent complications seen in patients with episcleritis are related to the use of long-term topical corticosteroids: Cataract, ocular hypertension, steroid-induced glaucoma, herpetic keratitis.

COURSE AND PROGNOSIS
Episcleritis is a mild, non-vision-threatening inflammation of the episclera that may recur over irregular intervals for many years.
It is important to recognize its benign nature and not to induce vision-threatening complications by overtreating episodes of episcleritis.

Scleritis is a granulomatous inflammation of the scleral coat of the eye.

Underlying systemic diseases
Other causes:
infection (e.g., syphilis, tuberculosis, bacterial, fungal, and herpes zoster).
trauma, surgery

Scleritis
Anterior scleritis
Non-necrotizing
Diffuse
Nodular
Necrotizing
With inflammation
Without inflammation
Posterior scleritis
Non-necrotizing
Diffuse
Nodular
Necrotizing with inflammation

Scleritis presents in the fourth to sixth decade with the gradual onset of classic symptoms of severe, boring, ocular pain that occasionally radiates to the temple, jaw, or sinuses,
redness, tearing ± photophobia

Differentiation between episcleritis and scleritis

Posterior scleritis
Posterior scleritis is a serious, potentially blinding condition, which is often misdiagnosed and treated very late.
Clinical features
• Mild–severe deep pain (may be referred to brow or jaw region), VA, diplopia, photopsia, hypermetropic shift.
• White eye (unless anterior involvement), lid edema, proptosis, lid retraction, restricted motility; choroidal folds, annular choroidal detachment, exudative retinal detachments, macular edema, disc edema.

Drugs commonly used in the treatment of scleritis
• Oral: NSAID (e.g., flurbiprofen 100 mg 3x/day; can be tapered down once disease is controlled).
• If not controlled, consider systemic immunosuppression: commonly corticosteroids (e.g., prednisone 1 mg/kg/day) ± other immunosuppressants (coordinate with rheumatologist).
• Topical corticosteroids are usually an adjunct to systemic therapy, lubrication
• Periocular corticosteroids (e.g., subtenons or transseptal triamcinolone acetonide) can be given in patients with no evidence of scleral thinning.
If there is risk of perforation, protect globe (e.g., glasses by day, shield at night) and consider scleral patch graft.

Complications
Кeratitis
Uveitis
Staphyloma.
Perforation of the sclera
Exudative retinal detachment and choroidal detachment

The orbit is a pear-shaped cavity in the skull
The orbit consist of the eyeball, external muscles, lacrimal gland, nerves, vessels, fat

Optic canal (orbital foramen):
Within lesser wing of sphenoid
Transmits: Optic nerve (CN 2), ophthalmic artery, and sympathetic nerves to ocular and orbital blood vessels

The inferior orbital fissure
Bordered medially by maxillary bone, anteriorly by zygomatic bone, and laterally by greater wing of sphenoid
Transmits: CN V2, zygomatic nerve, inferior ophthalmic vein

The superior orbital fissure is a slit linking the
cranium and the orbit, between the greater and lesserwings of the sphenoid bone.
Transmits: CN III, IV, V1, VI, superior ophthalmic vein,
and sympathetic fibers

Syndrome of superior orbital fissure – progressive diplopia, ptosis, complete right third, fourth, and sixth cranial nerve palsies, midriasis, sensory loss along the distribution of the first division of the trigeminal nerve

Sinuses

Clinical and special investigations
Clinical examination, Palpation of anterior orbital tissues
Orbitotonometry
Exophthalmometry
Ultrasonography
Magnetic resonance imaging; fat-suppression techniques
Arteriography
Radionuclide scan
Computed tomography, contrast-enhanced; bone-window (especially for fractures)

ORBITAL DISORDERS
Congenital orbital malformations
Infections
Orbital periostitis,
Cellulitis, Cavernous Sinus Thrombosis
Trauma
Thyroid-Related Ophthalmopathy
Vascular Abnormalities
Tumors
Acquired

Osteoperiostitis
It may result from injuries or as an extension of infection from the surrounding structures
Clinical picture may be in two forms.
Anterior orbital periostitis – it involves the orbital margin and is characterized by severe pain, tenderness and swelling of the inflammed area. Subperiostal abscess when formed, frequently bursts on the skin surface.
Posterior periostitis is characterized by deep seated orbital pain, exophthalmos, slight limitation of ocular movements. Sometimes there may be anaesthesia of the skin of eyelids and cornea.

Cellulitis
- inflammation of the orbit

Risk factors:
• Sinus disease: ethmoidal sinusitis (common), maxillary sinusitis.
• Infection of other adjacent structures: preseptal or facial infection, dacryocystitis, dental abscess.
• Trauma: septal perforation.
• Surgical: orbital, lacrimal, and vitreoretinal surgery.

Symptoms include rapid onset of headache, fever, pain, nausea, in some cases – prostration.
Eyelids are swollen, erythematous, warm and tender to palpation.
A marked chemosis of conjunctiva.
The eye is proptosed axially (the most frequently proptosis is lateral and downwards).
Ocular movements are restricted and painful.
In advanced cases visual acuity may be diminished.

Potential complications:
Intracranial complications include meningitis, brain abscess and cavernosus sinus thrombosis
Subperiorbital abscess (it is relatively rare in sinus-related orbital cellulitis but may occur in post-traumatic and postoperative cases)
Ocular complications (keratopathy, raised IOP, occlusion of the central retinal artery or vein, optic neuritis)

Principles of treatment of inflammatory diseases of the orbit
It is an emergency requiring hospital admission.
Intensive antibiotic therapy (topical (subconjunctival and retrobulbar injections). Admit for intravenous antibiotics (e.g., either floxacillin 500–1000 mg 4x/day or cefuroxime 750–1500 mg 3x/day with metronidazole 500 mg 3x/day).
Analgetics and anti-inflammatory drugs if necessary
Osmotherapy (40% glucosae solution)
Surgical drainage. In most cases it is necessary to drain both the orbit and the infected paranasal sinuses.
Physiotherapeutical treatment