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A positive VDRL of Treponema pallidum immobilization test confirms diagnosis of luetic(syphilitic) interstitial keratitis
Scleritis is best detected by examining the sclera in daylight; retracting the lids helps determine the extent of involvement. Other aspects of the eye exam (i.e. visual acuity testing, slit lamp examination, etc.) may be normal. Scleritis may be differentiated from episcleritis by using phenylephrine or neosynephrine eye drops, which causes blanching of the blood vessels in episcleritis, but not in scleritis.
Ancillary tests CT scans, MRIs, and ultrasonographies can be helpful, but do not replace the physical examination.
Previous long-standing eye infection which possibly during childhood time recalled as being treated with antibiotic and/or hospitalized over long period of time.
Diagnosis is done by direct observation under magnified view of slit lamp revealing the ulcer on the cornea. The use of fluorescein stain, which is taken up by exposed corneal stroma and appears green, helps in defining the margins of the corneal ulcer, and can reveal additional details of the surrounding epithelium. Herpes simplex ulcers show a typical dendritic pattern of staining. Rose-Bengal dye is also used for supra-vital staining purposes, but it may be very irritating to the eyes. In descemetoceles, the Descemet's membrane will bulge forward and after staining will appear as a dark circle with a green boundary, because it does not absorb the stain. Doing a corneal scraping and examining under the microscope with stains like Gram's and KOH preparation may reveal the bacteria and fungi respectively. Microbiological culture tests may be necessary to isolate the causative organisms for some cases. Other tests that may be necessary include a Schirmer's test for keratoconjunctivitis sicca and an analysis of facial nerve function for facial nerve paralysis.
Scleritis can be classified as anterior scleritis and posterior scleritis. Anterior scleritis is the most common variety, accounting for about 98% of the cases. It is of two types : Non-necrotising and necrotising. Non-necrotising scleritis is the most common, and is further classified into diffuse and nodular type based on morphology. Necrotising scleritis accounts for 13% of the cases. It can occur with or without inflammation.
NK is diagnosed on the basis of the patient's medical history and a careful examination of the eye and surrounding area.
With regard to the patient's medical history, special attention should be paid to any herpes virus infections and possible surgeries on the cornea, trauma, abuse of anaesthetics or chronic topical treatments, chemical burns or, use of contact lenses. It is also necessary to investigate the possible presence of diabetes or other systemic diseases such as multiple sclerosis.
The clinical examination is usually performed through a series of assessments and tools:
- General examination of cranial nerves, to determine the presence of nerve damage.
- Eye examinations:
1. Complete eye examination: examination of the eyelids, blink rate, presence of inflammatory reactions and secretions, corneal epithelial alterations.
2. Corneal sensitivity test: performed by placing a cotton wad or cotton thread in contact with the corneal surface: this only allows to determine whether corneal sensitivity is normal, reduced or absent; or using an esthesiometer that allows to assess corneal sensitivity.
3. Tear film function test, such as Schirmer's test, and tear film break-up time.
4. Fluorescein eye stain test, which shows any damage to the corneal and conjunctival epithelium
The diagnosis of episcleritis is based upon the history and physical examination. The history should be explored for the presence of the diseases associated with episcleritis, and the symptoms they cause, such as rash, arthritis, venereal disease, and recent viral infection. Episcleritis may be differentiated from scleritis by using phenylephrine or neosynephrine eye drops, which causes blanching of the blood vessels in episcleritis, but not in scleritis. A blue color to the sclera suggests scleritis, rather than episcleritis.
After anesthetizing the eye with medication, the conjunctiva may be moved with a cotton swab to observe the location of the enlarged blood vessels.
Corneal perforation can be diagnosed by using the Seidel test. Any aqueous leakage is revealed during the Seidel test confirms corneal perforation. A fluorescence strip is wiped over the wound. If the clear aqueous humor from the eye runs through the yellow stain, the patient tests positive for corneal perforation.
According to Mackie's classification, neurotrophic keratitis can be divided into three stages based on severity:
1. "Stage I:" characterized by alterations of the corneal epithelium, which is dry and opaque, with superficial punctate keratopathy and corneal oedema. Long-lasting neurotrophic keratitis may also cause hyperplasia of the epithelium, stromal scarring and neovascularization of the cornea.
2. "Stage II:" characterized by development of epithelial defects, often in the area near the centre of the cornea.
3. "Stage III:" characterized by ulcers of the cornea accompanied by stromal oedema and/or melting that may result in corneal perforation.
Although corneal abrasions may be seen with ophthalmoscopes, slit lamp microscopes provide higher magnification which allow for a more thorough evaluation. To aid in viewing, a fluorescein stain that fills in the corneal defect and glows with a cobalt blue-light is generally instilled first.
A careful search should be made for any foreign body, in particular looking under the eyelids. Injury following use of hammers or power-tools should always raise the possibility of a penetrating foreign body into the eye, for which urgent ophthalmology opinion should be sought.
The erosion may be seen by an eye doctor using the magnification of a biomicroscope or slit lamp. Usually fluorescein stain must be applied first and a cobalt blue-light used, but may not be necessary if the area of the epithelial defect is large. Optometrists and ophthalmologists have access to the slit lamp microscopes that allow for this more-thorough evaluation under the higher magnification. Mis-diagnosis of a scratched cornea is fairly common, especially in younger patients.
Intraocular pressure should be measured as part of the routine eye examination.
It is usually only elevated by iridocyclitis or acute-closure glaucoma, but not by relatively benign conditions.
In iritis and traumatic perforating ocular injuries, the intraocular pressure is usually low.
In advanced stages, corneal neovascularization can threaten eyesight, which is why routine (annual) eye exams are recommended for contact lens patients.
Complications are the exception rather than the rule from simple corneal abrasions. It is important that any foreign body be identified and removed, especially if containing iron as rusting will occur.
Occasionally the healed epithelium may be poorly adherent to the underlying basement membrane in which case it may detach at intervals giving rise to recurrent corneal erosions.
Episcleritis is a benign, self-limiting condition, meaning patients recover without any treatment. Most cases of episcleritis resolve within 7–10 days. The nodular type is more aggressive and takes longer to resolve. Although rare, some cases may progress to scleritis. However, in general, episcleritis does not cause complications in the eye. Smoking tobacco delays the response to treatment in patients with episcleritis.
The treatment of corneal perforation depends on the location, severity and the cause of damage
- Tissue adhesive can be used to seal small perforation, but this method cannot be used to treat perforations larger than 1 mm.
- Non infected corneal perforation generally heals when a pressure bandage is used.
- For certain types of corneal perforations, lamellar keratoplasty is used as treatment.
Topical antibiotics are used at hourly intervals to treat infectious corneal ulcers. Cycloplegic eye drops are applied to give rest to the eye. Pain medications are given as needed. Loose epithelium and ulcer base can be scraped off and sent for culture sensitivity studies to find out the pathogenic organism. This helps in choosing appropriate antibiotics. Complete healing takes anywhere from about a few weeks to several months.
Refractory corneal ulcers can take a long time to heal, sometimes months. In case of progressive or non-healing ulcers, surgical intervention by an ophthalmologist with corneal transplantation may be required to save the eye. In all corneal ulcers it is important to rule out predisposing factors like diabetes mellitus and immunodeficiency.
Treatment of herpes of the eye is different based on its presentation: epithelial keratitis is caused by live virus while stromal disease is an immune response and metaherpetic ulcer results from inability of the corneal epithelium to heal:
In an eye with iridocyclitis, (inflammation of both the iris and ciliary body), the involved pupil will be smaller than the uninvolved, due to reflex muscle spasm of the sphincter muscle of the iris.
Generally, conjunctivitis does not affect the pupils.
With acute angle-closure glaucoma, the pupil is generally fixed in mid-position, oval, and responds sluggishly to light, if at all.
Shallow anterior chamber depth may indicate a predisposition to one form of glaucoma (narrow angle) but requires slit-lamp examination or other special techniques to determine it.
In the presence of a "red eye", a shallow anterior chamber may indicate acute glaucoma, which requires immediate attention.
Treatments for corneal neovascularization are predominately off-lab with a multitude of complications as a result. The desired results from medical therapy may not always occur, ergo an invasive procedure may be needed to prevent further decrease in corneal avascularity.
For contact lenses related hypoxia, ceasing the use of contact lenses is the first step until corneal neovascularization is addressed by a physician. Modern rigid gas permeable and silicon hydrogel contact lenses have a much higher level of oxygen transmissibility, making them effective alternatives to help prevent corneal neovascularization.
Topical administration of steroids and non-steroid anti-inflammatory drugs are first-line treatment for individuals with CNV. The administration of steroids can increase the risk of infection, glaucoma, cataracts, herpes simplex recurrence. The anti-inflammatory drugs, however, increase the risk of corneal ulceration and melting.
Since VEGF plays an important role in vasculogenesis and pathologic neovascularization associated with eye diseases, a potential treatment for CNV is to inhibit VEGF activity by competing the binding of VEGF with specific neutralizing anti-VEGF antibody. VEGF inhibitors include pegatanib sodium, ranibizumab, and off-label bevacizumab are currently used for treatment of various retinal disease. Anti-VEGF antibodies such as the application of ranibizumab or bevacizumab have has been shown to reduce corneal neovascularization. Both ranibizumab and bevacizumab uses the same mechanism and inhibits all iso-forms of VEGF. The significant reduction in invasion of in-growth blood vessels in terms of neovascular area and vessel caliber suggests that treatment with ranibizumab induces thinning of the blood vessels, however, there's no significant change of the blood vessel's length. Using anti-VEGF antibodies to treat CNV has some limitations such as it is not a cure and may require repeated treatments to maintain positive effects over time. Topical and/or subconjunctival administration of bevaicizumab or ranibizumab have demonstrated short-term safety and efficacy, however long term effects have not been documented. Anti-VEGF therapy is currently an experimental treatment.
If the cornea is inflamed via corneal neovascularization, the suppression of enzymes can block CNV by compromising with corneal structural integrity. Corneal neovascularization can be suppressed with a combination of orally administration of doxycycline and with topical corticosteroid.
Surgical Options
Invasive solutions for corneal neovascularization are reserved when the medical therapies do not provide the desired results.
Invading blood tissues and ablating tissues in the cornea can be obstructed by the use of laser treatments such as Argon and s. Irradiation and/or damages to adjacent tissues caused by the procedure can result in corneal hemorrhage and corneal thinning. Obstruction of the blood vessels can be unsuccessful due to the depth, size, and, high blood flow rate of the vessels. In conjunction, thermal damage from the lasers can trigger inflammatory response which can exaggerate the neovascularization.
An effective treatment is photodynamic therapy, however, this treatment has limited clinical acceptance due to high costs and many potential complications involved that are also related to laser ablation. Complications can include irradiation from previously injected photosensitive dye inducing apoptosis and necrosis of the endothelium and basement membrane.
Diathermy and cautery is a treatment where an electrolysis needle is inserted into the feeder vessels in the limbus. The vessels are obstructed by a coagulating current through the use of unipolar diathermy unit or by thermal cautery.
The effect is normally temporary and after a period of six to eight weeks, the cornea usually returns to its former transparency. The recovery can be aided nonsurgically by bandaging with an osmotic saline solution. Non-steroidal anti-inflammatory topical may be used to reduce the pain and inflammation.
A specific clinical diagnosis of HSV as the cause of dendritic keratitis can usually be made by ophthalmologists and optometrists based on the presence of characteristic clinical features. Diagnostic testing is seldom needed because of its classic clinical features and is not useful in stromal keratitis as there is usually no live virus. Laboratory tests are indicated in complicated cases when the clinical diagnosis is uncertain and in all cases of suspected neonatal herpes infection:
- Corneal smears or impression cytology specimens can be analyzed by culture, antigen detection, or fluorescent antibody testing. Tzanck smear, i.e.Papanicolaou staining of corneal smears, show multinucleated giant cells and intranuclear inclusion bodies, however, the test is low in sensitivity and specificity.
- DNA testing is rapid, sensitive and specific. However, its high cost limits its use to research centers.
- Demonstration of HSV is possible with viral culture.
- Serologic tests may show a rising antibody titer during primary infection but are of no diagnostic assistance during recurrent episodes.
Given that episodes tend to occur on awakening and managed by use of good 'wetting agents', approaches to be taken to help prevent episodes include:
- Environmental:
- ensuring that the air is humidified rather than dry, not overheated and without excessive airflow over the face. Also avoiding irritants such as cigarette smoke.
- use of protective glasses especially when gardening or playing with children.
- General personal measures:
- maintaining general hydration levels with adequate fluid intake.
- not sleeping-in late as the cornea tends to dry out the longer the eyelids are closed.
- Pre-bed routine:
- routine use of long-lasting eye ointments applied before going to bed.
- occasional use of the anti-inflammatory eyedrop FML (prescribed by an ophthalmologist or optometrist) before going to bed if the affected eye feels inflamed, dry or gritty
- use of a hyperosmotic (hypertonic) ointment before bed reduces the amount of water in the epithelium, strengthening its structure
- use the pressure patch as mentioned above.
- use surgical tape to keep the eye closed (if Nocturnal Lagophthalmos is a factor)
- Waking options:
- learn to wake with eyes closed and still and keeping artificial tear drops within reach so that they may be squirted under the inner corner of the eyelids if the eyes feel uncomfortable upon waking.
- It has also been suggested that the eyelids should be rubbed gently, or pulled slowly open with your fingers, before trying to open them, or keeping the affected eye closed while "looking" left and right to help spread lubricating tears. If the patient's eyelids feel stuck to the cornea on waking and no intense pain is present, use a fingertip to press firmly on the eyelid to push the eye's natural lubricants onto the affected area. This procedure frees the eyelid from the cornea and prevents tearing of the cornea.
A hypopyon should not be drained, because it offers protection against the invading pathogen due to the presence of white blood cells, although long-standing hypopyon can cause close-angle glaucoma and anterior synechiae.
Hypopyon can be present in a corneal ulcer. Behcet's disease, endophthalmitis, panuveitis/panophthalmitis and adverse reactions to some drugs (such as rifabutin).
Hypopyon is also known as "sterile pus", as it occurs due to the release of toxins and not by the actual invasion of pathogens. The toxins secreted by the pathogens mediate the outpouring of leukocytes that settle in the anterior chamber of the eye. .
An inverse hypopyon is different from a standard hypopyon. Inverse hypopyon is seen after a pars plana vitrectomy with an insertion of silicone oil (as a replacement of the vitreous humour that has been removed in the operation; the silicone oil maintains internal tamponade). When the silicone oil emulsifies, it seeps into the anterior chamber and settles at the top of the anterior chamber. This is in contrast to hypopyon resulting from toxins where the leukocytes settle at the bottom of the anterior chamber. This is due to the effect of gravity, hence the name inverse hypopyon.