When it comes to managing viral conjunctivitis, it’s important to reassure the patient that most cases are self-limiting and don’t require antimicrobial treatment. In fact, viral conjunctivitis usually resolves on its own within one to two weeks. However, there are some self-care measures that can help ease symptoms. These include cleaning the eyelids with cotton wool soaked in sterile saline or boiled and cooled water, applying cool compresses around the eye area, and using lubricating drops or artificial tears. It’s also important to avoid prescribing antibiotics if possible.

It’s crucial to inform the person that infective conjunctivitis is contagious and they should take steps to prevent spreading the infection to their other eye and other people. This includes washing hands frequently with soap and water, using separate towels and flannels, and avoiding close contact with others, especially if they are a healthcare professional or child-care provider. It’s worth noting that the infection can be contagious for up to 14 days from onset.

According to Public Health England, there is no recommended exclusion period from school, nursery, or childminders unless there is an outbreak or cluster of cases. It’s important to provide written information to the patient, explain the red flags for an urgent review, and advise them to seek further help if symptoms persist beyond 7 days. If the person returns with symptoms of conjunctivitis, it may be necessary to consider sending swabs for viral PCR and bacterial culture, as well as prescribing empirical topical antibiotics if they haven’t already been prescribed. If symptoms persist for more than 7-10 days after initiating treatment, it may be necessary to discuss with or refer to ophthalmology.

Anterior uveitis refers to the inflammation of the middle layer of the eye, which includes the iris and the ciliary body. If left untreated, it can lead to permanent damage and vision loss due to the development of conditions like glaucoma, cataract, or retinal edema.

There are various causes of anterior uveitis, including eye trauma from being hit or having a foreign object in the eye. It can also be associated with inflammatory disorders such as ankylosing spondylitis.

The clinical features of anterior uveitis are characterized by a red and sore eye, accompanied by pain that worsens when the ciliary muscles contract. Other symptoms include watering of the eye, blurred vision, sensitivity to light (photophobia), and a constricted or distorted pupil. The visual acuity may be normal or reduced.

Overall, anterior uveitis is a condition that requires prompt attention and treatment to prevent further complications and preserve vision.

The orbicularis oculi muscle encircles the eye socket and extends into the eyelid. It is composed of two parts: the orbital part, which forcefully closes the eye, and the palpebral part, which gently closes the eye. The innervation of the orbicularis oculi muscle is provided by the facial nerve. In the event of facial nerve damage, the orbicularis oculi muscle loses its functionality. As the sole muscle responsible for closing the eyelids, this can have significant clinical implications. The inability to shut the eye can lead to dryness of the cornea and the development of exposure keratitis. While mild cases can be managed with regular use of eye drops, severe cases may require surgical closure of the eye.

Here is a revised version of the guidance on the management of bacterial conjunctivitis:

– It is important to inform the patient that most cases of bacterial conjunctivitis will resolve on their own within 5-7 days without any treatment.
– However, if the condition is severe or if there is a need for rapid resolution, topical antibiotics may be prescribed. In some cases, a delayed treatment strategy may be appropriate, and the patient should be advised to start using topical antibiotics if their symptoms have not improved within 3 days.
– There are several options for topical antibiotics, including Chloramphenicol 0.5% drops (to be applied every 2 hours for 2 days, then 4 times daily for 5 days) and Chloramphenicol 1% ointment (to be applied four times daily for 2 days, then twice daily for 5 days). Fusidic acid 1% eye drops can also be used as a second-line treatment, to be applied twice daily for 7 days.
– It is important to note that there is no recommended exclusion period from school, nursery, or childminders for isolated cases of bacterial conjunctivitis. However, some institutions may have their own exclusion policies.
– Provide the patient with written information and explain the red flags that indicate the need for an urgent review.
– Arrange a follow-up appointment to confirm the diagnosis and ensure that the symptoms have resolved.
– If the patient returns with ongoing symptoms, it may be necessary to send swabs for viral PCR (to test for adenovirus and Herpes simplex) and bacterial culture. Empirical topical antibiotics may also be prescribed if they have not been previously given.
– Consider referring the patient to ophthalmology if the symptoms persist for more than 7 to 10 days after initiating treatment.

For more information, you can refer to the NICE Clinical Knowledge Summary on Infective Conjunctivitis.

Cement contains lime, which is a powerful alkali, and this can cause a serious eye emergency that requires immediate treatment. Alkaline chemicals, such as oven cleaner, ammonia, household bleach, drain cleaner, oven cleaner, and plaster, can also cause damage to the eyes. They lead to colliquative necrosis, which is a type of tissue death that results in liquefaction. On the other hand, acids cause damage through coagulative necrosis. Common acids that can harm the eyes include toilet cleaners, certain household cleaning products, and battery fluid.

The initial management of a patient with cement or alkali exposure to the eyes should be as follows:

1. Irrigate the eye with a large amount of normal saline for 20-30 minutes.
2. Administer local anaesthetic drops every 5 minutes to help keep the eye open and alleviate pain.
3. Monitor the pH every 5 minutes until a neutral pH (7.0-7.5) is achieved. Briefly pause irrigation to test the fluid from the forniceal space using litmus paper.

After the initial management, a thorough examination should be conducted, which includes the following steps:

1. Examine the eye directly and with a slit lamp.
2. Remove any remaining cement debris from the surface of the eye.
3. Evert the eyelids to check for hidden cement debris.
4. Administer fluorescein drops and check for corneal abrasion.
5. Assess visual acuity, which may be reduced.
6. Perform fundoscopy to check for retinal necrosis if the alkali has penetrated the sclera.
7. Measure intraocular pressure through tonometry to detect secondary glaucoma.

Once the eye’s pH has returned to normal, irrigation can be stopped, and the patient should be promptly referred to an ophthalmology specialist for further evaluation.

Potential long-term complications of cement or alkali exposure to the eyes include closed-angle glaucoma, cataract formation, entropion, keratitis sicca, and permanent vision loss.

Retinal detachment is a condition where the retina separates from the retinal pigment epithelium, resulting in a fluid-filled space between them. This case presents a classic description of retinal detachment. Several risk factors increase the likelihood of developing this condition, including myopia, being male, having a family history of retinal detachment, previous episodes of retinal detachment, blunt ocular trauma, previous cataract surgery, diabetes mellitus (especially if proliferative retinopathy is present), glaucoma, and cataracts.

The clinical features commonly associated with retinal detachment include flashes of light, particularly at the edges of vision (known as photopsia), a dense shadow in the peripheral vision that spreads towards the center, a sensation of a curtain drawing across the eye, and central visual loss. Fundoscopy, a procedure to examine the back of the eye, reveals a sheet of sensory retina billowing towards the center of the eye. Additionally, a positive Amsler grid test, where straight lines appear curved or wavy, may indicate retinal detachment.

Other possible causes of floaters include posterior vitreous detachment, retinal tears, vitreous hemorrhage, and migraine with aura. However, in this case, the retinal appearance described is consistent with retinal detachment.

It is crucial to arrange an urgent same-day ophthalmology referral for this patient. Fortunately, approximately 90% of retinal detachments can be successfully repaired with one operation, and an additional 6% can be salvaged with subsequent procedures. If the retina remains fixed six months after surgery, the likelihood of it becoming detached again is low.

The presentation, in this instance, is consistent with retinal (ocular) migraine. As per the International Headache Society, the primary clinical features of retinal migraine include an expanding blind-spot in the center of vision, flickering or flashing lights, temporary loss of vision in one eye lasting less than an hour, headache lasting anywhere from 4 to 72 hours (often affecting only one side of the head), nausea and vomiting, sensitivity to light and sound, and a prodrome present in 50-60% of cases. Retinal migraine is relatively uncommon, affecting only 1 in 200 individuals with migraines, and is believed to occur due to the narrowing of blood vessels in the choroidal or retinal arteries. Factors that can trigger retinal migraine include recent intense exercise, changes in posture, and the use of oral contraceptives.

Acute optic neuritis typically presents with unilateral vision loss that worsens over a couple of weeks and then spontaneously improves within three weeks. This condition is more commonly seen in individuals under the age of 45 and is often accompanied by pain around the eyes that worsens with eye movement. A relative afferent pupillary defect and pallor of the optic disc, visible 4-6 weeks after the onset, are frequently observed. The most common cause of optic neuritis in this age group is acute demyelination.

Retinal hemorrhage leads to painless vision loss, while acute glaucoma and amaurosis fugax are unlikely to occur in individuals of this age group.

Sexually transmitted eye infections can be quite severe and are often characterized by prolonged mucopurulent discharge. There are two main causes of these infections: Chlamydia trachomatis and Neisseria gonorrhoea. Differentiating between the two can be done by considering certain features.

Chlamydia trachomatis infection typically presents with chronic low-grade irritation and mucous discharge that lasts for more than two weeks in sexually active individuals. It may also be accompanied by pre-auricular lymphadenopathy. This type of infection is usually unilateral but can sometimes affect both eyes.

On the other hand, Neisseria gonorrhoea infection tends to develop rapidly, usually within 12 to 24 hours. It is characterized by copious mucopurulent discharge, eyelid swelling, and tender preauricular lymphadenopathy. This type of infection carries a higher risk of complications, such as uveitis, severe keratitis, and corneal perforation.

Based on the patient’s symptoms, it appears that they are more consistent with a Neisseria gonorrhoea infection. The rapid onset, copious discharge, and tender preauricular lymphadenopathy are indicative of this type of infection.

Treatment for gonococcal conjunctivitis in adults is typically based on limited research. However, a study has shown that all 12 patients responded well to a single 1 g intramuscular injection of ceftriaxone, along with a single episode of ocular lavage with saline.

In summary, sexually transmitted eye infections can be caused by either Chlamydia trachomatis or Neisseria gonorrhoea. Differentiating between the two is important in order to provide appropriate treatment. The patient in this case exhibits symptoms that align more closely with a Neisseria gonorrhoea infection, which carries a higher risk of complications. Treatment options for gonococcal conjunctivitis are limited, but a single injection of ceftriaxone has shown positive results in previous studies.

Sexually transmitted eye infections can be quite severe and are often characterized by prolonged mucopurulent discharge. There are two main causes of these infections: Chlamydia trachomatis and Neisseria gonorrhoea. Differentiating between the two can be done by considering certain features.

Chlamydia trachomatis infection typically presents with chronic low-grade irritation and mucous discharge that lasts for more than two weeks in sexually active individuals. It may also be accompanied by pre-auricular lymphadenopathy. This type of infection is usually unilateral but can sometimes affect both eyes.

On the other hand, Neisseria gonorrhoea infection tends to develop rapidly, usually within 12 to 24 hours. It is characterized by copious mucopurulent discharge, eyelid swelling, and tender preauricular lymphadenopathy. This type of infection carries a higher risk of complications, such as uveitis, severe keratitis, and corneal perforation.

Based on the patient’s symptoms, it appears that they are more consistent with a Neisseria gonorrhoea infection. The rapid onset, copious discharge, and tender preauricular lymphadenopathy are indicative of this type of infection.

Treatment for gonococcal conjunctivitis in adults is typically based on limited research. However, a study has shown that all 12 patients responded well to a single 1 g intramuscular injection of ceftriaxone, along with a single episode of ocular lavage with saline.

In summary, sexually transmitted eye infections can be caused by either Chlamydia trachomatis or Neisseria gonorrhoea. Differentiating between the two is important in order to provide appropriate treatment. The patient in this case exhibits symptoms that align more closely with a Neisseria gonorrhoea infection, which carries a higher risk of complications. Treatment options for gonococcal conjunctivitis are limited, but a single injection of ceftriaxone has shown positive results in previous studies.

Behçet’s syndrome is a systemic vasculitis that is mediated by the immune system. It is characterized by various symptoms, including polyarthritis, which primarily affects large joints. Additionally, patients with Behçet’s syndrome often experience recurrent oral and genital ulcers. Ocular disease is also common, with manifestations such as uveitis, hypopyon, and iridocyclitis. Furthermore, neurological involvement can occur, leading to demyelination, parkinsonism, and dementia. In this particular case, the patient’s eye examination reveals features consistent with anterior uveitis and the presence of a hypopyon. While several conditions can cause anterior uveitis, the patient’s history of joint pain in large joints and recurrent oral and genital ulcers strongly suggest Behçet’s syndrome as the most likely diagnosis.

When it comes to managing bacterial conjunctivitis, NICE provides some helpful guidance. It is important to inform the patient that most cases of bacterial conjunctivitis will resolve on their own within 5-7 days without any treatment. However, in severe cases or situations where a quick resolution is necessary, topical antibiotics may be necessary. In some cases, it may be appropriate to delay treatment and advise the patient to start using topical antibiotics if their symptoms have not improved within 3 days.

There are a few options for topical antibiotics that can be used. One option is Chloramphenicol 0.5% drops, which should be applied every 2 hours for 2 days and then 4 times daily for 5 days. Another option is Chloramphenicol 1% ointment, which should be applied four times daily for 2 days and then twice daily for 5 days. Fusidic acid 1% eye drops can also be used as a second-line treatment and should be applied twice daily for 7 days.

By following these guidelines, healthcare professionals can effectively manage bacterial conjunctivitis and provide appropriate treatment options for their patients.

Scleritis is a serious condition characterized by inflammation of the sclera, the white outer layer of the eye. It often affects both eyes, with bilateral involvement seen in about half of the cases. While the cause of scleritis can be unknown (idiopathic), it is associated with systemic inflammatory diseases like rheumatoid arthritis in approximately one-third of patients. In fact, scleritis can sometimes be the initial manifestation of these inflammatory conditions.

The clinical features of scleritis include moderate to severe pain, which can be felt in the brow or jaw. The pain worsens with eye movement and may disrupt sleep. The onset of symptoms is typically gradual. Other common symptoms include sensitivity to light (photophobia), excessive tearing (epiphora), and redness of both the superficial and deep episcleral vessels. The affected eye may also be tender to touch, and there may be a decrease in visual acuity. Some individuals may have a history of previous episodes of scleritis.

In summary, scleritis is a serious inflammatory disease of the sclera that can be associated with systemic inflammatory conditions. It presents with significant pain, often referred to the brow or jaw, and worsened by eye movement. Other symptoms include photophobia, excessive tearing, and redness of the episcleral vessels. It is important to recognize scleritis as it can be the first sign of underlying inflammatory diseases.

Epidemic keratoconjunctivitis is a type of viral conjunctivitis that is primarily caused by adenoviruses. This highly contagious condition tends to occur in outbreaks. It is a common cause of acute conjunctivitis and has distinct clinical features. These include the sudden onset of acute follicular conjunctivitis, severe pain in the affected eye, a significant amount of watery discharge, the presence of subconjunctival hemorrhages, potential visual changes, hyperemia and chemosis, and the possibility of membranes and pseudomembranes forming. Additionally, ipsilateral preauricular lymphadenopathy may be observed.

There are two types of infectious agents that can lead to the development of a dendritic ulcer. The majority of cases (80%) are caused by the herpes simplex virus (type I), while the remaining cases (20%) are caused by the herpes zoster virus. To effectively treat this condition, the patient should follow a specific treatment plan. This includes applying acyclovir ointment topically five times a day for a duration of 10 days. Additionally, prednisolone 0.5% drops should be used 2-4 times daily. It is also recommended to take oral high dose vitamin C, as it has been shown to reduce the healing time of dendritic ulcers.

The optic chiasm is situated just below the hypothalamus and is in close proximity to the pituitary gland. When the pituitary gland enlarges, it can impact the functioning of the optic nerve at this location. Specifically, the fibres from the nasal half of the retina cross over at the optic chiasm to form the optic tracts. Compression at the optic chiasm primarily affects these fibres, resulting in a visual defect that affects peripheral vision in both eyes, known as bitemporal hemianopia. There are several causes of optic chiasm lesions, with the most common being a pituitary tumor. Other causes include craniopharyngioma, meningioma, optic glioma, and internal carotid artery aneurysm. The diagram below provides a summary of the different visual field defects that can occur at various points in the visual pathway.

This patient has presented with acute closed-angle glaucoma, which is a serious eye condition requiring immediate medical attention. It occurs when the iris pushes forward and blocks the fluid access to the trabecular meshwork, leading to increased pressure within the eye and damage to the optic nerve.

The main symptoms of acute closed-angle glaucoma include severe eye pain, decreased vision, redness around the cornea, swelling of the cornea, a fixed semi-dilated pupil, nausea, vomiting, and episodes of blurred vision or seeing haloes.

To confirm the diagnosis, tonometry is performed to measure the intraocular pressure. Normal pressure ranges from 10 to 21 mmHg, but in acute closed-angle glaucoma, it is often higher than 30 mmHg. Goldmann’s applanation tonometer is commonly used in hospitals for this purpose.

Management of acute closed-angle glaucoma involves providing pain relief, such as morphine, and antiemetics if the patient is experiencing vomiting. Intravenous acetazolamide is administered to reduce intraocular pressure. Additionally, a topical miotic medication like pilocarpine is started about an hour after initiating other treatments to help constrict the pupil, as it may initially be paralyzed and unresponsive.

Overall, acute closed-angle glaucoma is a medical emergency that requires prompt intervention to alleviate symptoms and prevent further damage to the eye.

There are two types of infectious agents that can lead to the development of a dendritic ulcer. The majority of cases (80%) are caused by the herpes simplex virus (type I), while the remaining cases (20%) are caused by the herpes zoster virus. To effectively treat this condition, the patient should follow a specific treatment plan. This includes applying aciclovir ointment topically five times a day for a duration of 10 days. Additionally, prednisolone 0.5% drops should be used 2-4 times daily. It is also recommended to take oral high dose vitamin C, as it has been shown to reduce the healing time of dendritic ulcers.

The pupillary light reflex is a reflex that regulates the size of the pupil in response to the intensity of light that reaches the retina. It consists of two separate pathways, the afferent pathway and the efferent pathway.

The afferent pathway begins with light entering the pupil and stimulating the retinal ganglion cells in the retina. These cells then transmit the light signal to the optic nerve. At the optic chiasm, the nasal retinal fibers cross to the opposite optic tract, while the temporal retinal fibers remain in the same optic tract. The fibers from the optic tracts then project and synapse in the pretectal nuclei in the dorsal midbrain. From there, the pretectal nuclei send fibers to the ipsilateral Edinger-Westphal nucleus via the posterior commissure.

On the other hand, the efferent pathway starts with the Edinger-Westphal nucleus projecting preganglionic parasympathetic fibers. These fibers exit the midbrain and travel along the oculomotor nerve. They then synapse on post-ganglionic parasympathetic fibers in the ciliary ganglion. The post-ganglionic fibers, known as the short ciliary nerves, innervate the sphincter muscle of the pupils, causing them to constrict.

The result of these pathways is that when light is shone in one eye, both the direct pupillary light reflex (ipsilateral eye) and the consensual pupillary light reflex (contralateral eye) occur.

Lesions affecting the pupillary light reflex can be identified by comparing the direct and consensual reactions to light in both eyes. If the optic nerve of the first eye is damaged, both the direct and consensual reflexes in the second eye will be lost. However, when light is shone into the second eye, the pupil of the first eye will still constrict. If the optic nerve of the second eye is damaged, the second eye will constrict consensually when light is shone into the unaffected first eye. If the oculomotor nerve of the first eye is damaged, the first eye will have no direct light reflex, but the second eye will still constrict consensually. Finally, if the oculomotor nerve of the second eye is damaged, there will be no consensual constriction of the second eye when light is shone into the unaffected first eye.

The most probable diagnosis in this case is anterior uveitis, which refers to inflammation of the iris. It typically presents with symptoms such as a painful and red eye, sensitivity to light, excessive tearing, and decreased visual clarity. The photo above shows a possible indication of this condition, with the presence of pus in the front chamber of the eye, known as hypopyon.

Anterior uveitis can have various causes, including idiopathic cases where no specific cause is identified. Other potential triggers include trauma, chronic joint diseases like spondyloarthropathies and juvenile chronic arthritis, inflammatory bowel disease, psoriasis, sarcoidosis, and infections such as Lyme disease, tuberculosis, leptospirosis, herpes simplex virus (HSV), and varicella-zoster virus (VZV). Additionally, certain malignancies like non-Hodgkin lymphoma, ocular melanoma, and retinoblastoma can be associated with anterior uveitis.

It is worth noting that there is a strong link between the HLA-B27 genotype and anterior uveitis, with approximately 50% of patients having this genetic marker. In this particular case, the likely underlying diagnosis is ankylosing spondylitis, a condition characterized by chronic pain and stiffness in the mid-spine area and sacroiliitis. It is important to mention that around 30% of men with unilateral uveitis will be found to have ankylosing spondylitis.

Central retinal vein occlusion (CRVO) typically results in painless, one-sided vision loss. On fundoscopic examination, the retina displays a distinct appearance resembling a ‘pizza thrown against a wall’. This includes engorged retinal veins, swelling of the optic disc, multiple flame-shaped hemorrhages, and cotton wool spots. Hypertension is present in about 65% of CRVO patients, and it is more common in individuals over 65 years old.

In contrast, central retinal artery occlusion (CRAO) also causes sudden, painless, one-sided vision loss. However, the retina’s appearance in CRAO is different from CRVO. It appears pale, with narrowed blood vessels. A notable feature is the presence of a ‘cherry-red spot’ at the center of the macula, which is supplied by the underlying choroid. Examination often reveals an afferent pupillary defect.

Vitreous hemorrhage occurs when there is bleeding into the middle chamber of the eye, known as the vitreous. This can be caused by conditions such as proliferative diabetic retinopathy, trauma, or retinal detachment. The appearance of vitreous hemorrhage is described as ‘blood within a bloodless gel’, resulting in a diffuse red appearance of the retina. Unlike CRVO, there are no focal flame-shaped hemorrhages.

Diabetic maculopathy refers to the presence of diabetic eye disease within a one-disc diameter of the macula.

Wet age-related macular degeneration (ARMD) causes vision loss due to choroidal neovascularization, which leads to leakage of blood and protein beneath the macula. While there may be hemorrhages visible on the retina, the overall appearance does not match the description provided in the question.

This patient has presented with acute closed-angle glaucoma, which is a medical emergency in the field of ophthalmology. It occurs when the iris bows forward and blocks the fluid access to the trabecular meshwork, which is located at the entrance to Schlemm’s canal. As a result, the intraocular pressure rises and leads to glaucomatous optic neuropathy.

The main clinical features of acute closed-angle glaucoma include severe eye pain, loss of vision or decreased visual acuity, congestion and redness around the cornea, corneal swelling, a fixed semi-dilated oval-shaped pupil, nausea and vomiting, and preceding episodes of blurred vision or seeing haloes.

The diagnosis can be confirmed by tonometry, which measures the pressure inside the eye. The normal range of intraocular pressure is 10-21 mmHg, but in acute closed-angle glaucoma, it is often higher than 30 mmHg. Goldmann’s applanation tonometer is commonly used in hospitals for this purpose.

Management of acute closed-angle glaucoma should include providing pain relief, such as morphine, and antiemetics if the patient is experiencing vomiting. Intravenous administration of acetazolamide 500 mg is recommended to reduce intraocular pressure. Treatment with a topical miotic, like pilocarpine 1% or 2%, should be initiated approximately one hour after starting other measures, as the pupil may initially be paralyzed and unresponsive.

On the other hand, chronic open-angle glaucoma is a more common presentation than acute closed-angle glaucoma. It affects approximately 1 in 50 people over the age of 40 and 1 in 10 people over the age of 75. In this condition, there is a partial blockage within the trabecular meshwork, which hinders the drainage of aqueous humor and gradually increases intraocular pressure, leading to optic neuropathy. Unlike acute closed-angle glaucoma, chronic open-angle glaucoma does not cause eye pain or redness. It presents gradually with a progressive loss of peripheral vision, while central vision is relatively preserved.

Peri-orbital cellulitis, also known as preseptal cellulitis, is an infection that affects the eyelid and the skin surrounding the eye in front of the orbital septal. On the other hand, orbital cellulitis is a medical emergency that occurs when there is an infection in the tissues of the eye located behind the orbital septum.

The most common organisms that cause these infections include Streptococcus pneumoniae, Staphylococcus aureus, Streptococcus pyogenes, and Haemophilus influenzae.

Peri-orbital cellulitis may present with various symptoms, such as swelling of the eyelid, redness around the eye, discharge, difficulty closing the eye, conjunctival injection, mild fever, teary eyes, and discomfort.

To distinguish orbital cellulitis from peri-orbital cellulitis, it is important to look out for additional symptoms, including pain when moving the eye, protrusion of the eye (proptosis), redness of the eye (red desaturation), vision loss, eye muscle paralysis (ophthalmoplegia), double vision (diplopia), and optic nerve damage (optic neuropathy). These symptoms indicate a more severe condition that requires immediate medical attention.

Anterior uveitis refers to the inflammation of the iris and is characterized by a painful and red eye. It is often accompanied by symptoms such as sensitivity to light, excessive tearing, and a decrease in visual clarity. In less than 10% of cases, the inflammation may extend to the posterior chamber. The condition can also lead to the formation of adhesions between the iris and the lens or cornea, resulting in an irregularly shaped pupil known as synechia. In severe cases, pus may accumulate in the front part of the eye, specifically the anterior chamber, causing a condition called hypopyon.

There are various factors that can cause anterior uveitis, including idiopathic cases where no specific cause can be identified. Other causes include trauma, chronic joint diseases like spondyloarthropathies and juvenile chronic arthritis, ankylosing spondylitis, inflammatory bowel disease, psoriasis, sarcoidosis, and infections such as Lyme disease, tuberculosis, leptospirosis, herpes simplex virus (HSV), and varicella-zoster virus (VZV). It is worth noting that approximately 50% of patients with anterior uveitis have a strong association with the HLA-B27 genotype.

Complications that can arise from uveitis include the development of cataracts, glaucoma, band keratopathy (a condition where calcium deposits form on the cornea), and even blindness.

The optic chiasm is situated just below the hypothalamus and is in close proximity to the pituitary gland. When the pituitary gland enlarges, it can impact the functioning of the optic nerve at this location. Specifically, the fibres from the nasal half of the retina cross over at the optic chiasm to form the optic tracts. Compression at the optic chiasm primarily affects these fibres, resulting in a visual defect that affects peripheral vision in both eyes, known as bitemporal hemianopia. There are several causes of optic chiasm lesions, with the most common being a pituitary tumor. Other causes include craniopharyngioma, meningioma, optic glioma, and internal carotid artery aneurysm. The diagram below provides a summary of the different visual field defects that can occur at various points in the visual pathway.

Sexually transmitted eye infections can be quite severe and are often characterized by prolonged mucopurulent discharge. The two main causes of these infections are Chlamydia trachomatis and Neisseria gonorrhoea. Differentiating between the two can be done by considering certain features.

Chlamydia trachomatis infection typically presents with chronic low-grade irritation and mucous discharge that lasts for more than two weeks in sexually active individuals. Pre-auricular lymphadenopathy, or swelling of the lymph nodes in front of the ear, may also be present. Most cases of this infection are unilateral, affecting only one eye, but there is a possibility of it being bilateral, affecting both eyes.

On the other hand, Neisseria gonorrhoea infection tends to develop rapidly, usually within 12 to 24 hours. It is characterized by copious mucopurulent discharge, swelling of the eyelids, and tender preauricular lymphadenopathy. This type of infection carries a higher risk of complications, such as uveitis, severe keratitis, and corneal perforation.

Based on the patient’s symptoms, it appears that they are more consistent with a Chlamydia trachomatis infection, especially considering the slower and more gradual onset of their symptoms.

There is ongoing debate regarding the most effective antibiotic treatment for these infections. Some options include topical tetracycline ointment to be applied four times a day for six weeks, oral doxycycline to be taken twice a day for one to two weeks, oral azithromycin with a single dose of 1 gram followed by 500 mg orally for two days, or oral erythromycin to be taken four times a day for one week.

Cement contains lime, which is a powerful alkali, and this can cause a serious eye emergency that requires immediate treatment. Alkaline chemicals, such as oven cleaner, ammonia, household bleach, drain cleaner, oven cleaner, and plaster, can also cause damage to the eyes. They lead to colliquative necrosis, which is a type of tissue death that results in liquefaction. On the other hand, acids cause damage through coagulative necrosis. Common acids that can harm the eyes include toilet cleaners, certain household cleaning products, and battery fluid.

The initial management of a patient with cement or alkali exposure to the eyes should be as follows:

1. Irrigate the eye with a large amount of normal saline for 20-30 minutes.
2. Administer local anaesthetic drops every 5 minutes to help keep the eye open and alleviate pain.
3. Monitor the pH every 5 minutes until a neutral pH (7.0-7.5) is achieved. Briefly pause irrigation to test the fluid from the forniceal space using litmus paper.

After the initial management, a thorough examination should be conducted, which includes the following steps:

1. Examine the eye directly and with a slit lamp.
2. Remove any remaining cement debris from the surface of the eye.
3. Evert the eyelids to check for hidden cement debris.
4. Administer fluorescein drops and check for corneal abrasion.
5. Assess visual acuity, which may be reduced.
6. Perform fundoscopy to check for retinal necrosis if the alkali has penetrated the sclera.
7. Measure intraocular pressure through tonometry to detect secondary glaucoma.

Once the eye’s pH has returned to normal, irrigation can be stopped, and the patient should be promptly referred to an ophthalmology specialist for further evaluation.

Potential long-term complications of cement or alkali exposure to the eyes include closed-angle glaucoma, cataract formation, entropion, keratitis sicca, and permanent vision loss.

Homonymous quadrantanopias occur when there are lesions in the optic radiation. The optic tract passes through the posterolateral angle of the optic chiasm, running alongside the cerebral peduncle and inside the uncus of the temporal lobe. Eventually, it reaches the lateral geniculate body (LGN) in the thalamus. Acting as a relay center, the LGN sends axons through the optic radiation to the primary visual cortex in the occipital lobe. The upper optic radiation carries fibers from the superior retinal quadrants (which corresponds to the lower half of the visual field) and travels through the parietal lobe. On the other hand, the lower optic radiation carries fibers from the inferior retinal quadrants (which corresponds to the upper half of the visual field) and travels through the temporal lobe. Consequently, lesions in the temporal lobe can lead to superior homonymous quadrantanopias, while lesions in the parietal lobe can cause inferior homonymous quadrantanopias. The diagram below provides a summary of the different visual field defects resulting from lesions at various points in the visual pathway.

Central retinal artery occlusion (CRAO) is characterized by sudden and painless loss of vision in the affected eye. It can occur due to emboli from atheromatous carotid arteries, thrombosis caused by arteriosclerosis or hypertension, or vasospasm resulting from giant cell arteritis. The pupil on the affected side typically shows poor reactivity to light, but the consensual light reaction remains normal. The typical retinal findings in CRAO include a pale retina due to edema, narrowed blood vessels, segmentation of blood columns in arteries (resembling cattle-trucking), and a cherry red spot indicating sparing of the macular center supplied by the underlying choroid. Over several weeks, optic atrophy may develop. Immediate referral to an eye specialist is necessary as CRAO is an ophthalmological emergency.

On the other hand, central retinal vein occlusion (CRVO) leads to painless and unilateral visual loss. The retina in CRVO has a distinct appearance likened to a pizza thrown against a wall. Fundoscopic examination reveals engorged retinal veins, disc edema, multiple flame-shaped hemorrhages, and cotton wool spots.

Central retinal vein occlusion (CRVO) typically leads to painless, one-sided vision loss. When examining the retina, it may appear similar to a ‘pizza thrown against a wall’, with swollen retinal veins, swelling of the optic disc, multiple flame-shaped hemorrhages, and cotton wool spots. Hypertension is present in about 65% of CRVO patients, and it is more common in individuals over the age of 65. Other known risk factors include being elderly, having chronic glaucoma, arteriosclerosis, and polycythemia.

In contrast, central retinal artery occlusion (CRAO) is characterized by a pale retina and a ‘cherry-red spot’ in the macula’s center, which is spared due to its blood supply from the underlying choroid. It is important to differentiate between CRVO and CRAO based on these distinct features.

Sexually transmitted eye infections can be quite severe and are often characterized by prolonged mucopurulent discharge. The two main causes of these infections are Chlamydia trachomatis and Neisseria gonorrhoea. Differentiating between the two can be done by considering certain features.

Chlamydia trachomatis infection typically presents with chronic low-grade irritation and mucous discharge that lasts for more than two weeks in sexually active individuals. Pre-auricular lymphadenopathy, or swelling of the lymph nodes in front of the ear, may also be present. Most cases of this infection are unilateral, affecting only one eye, but there is a possibility of it being bilateral, affecting both eyes.

On the other hand, Neisseria gonorrhoea infection tends to develop rapidly, usually within 12 to 24 hours. It is characterized by copious mucopurulent discharge, swelling of the eyelids, and tender preauricular lymphadenopathy. This type of infection carries a higher risk of complications, such as uveitis, severe keratitis, and corneal perforation.

Based on the patient’s symptoms, it appears that they are more consistent with a Chlamydia trachomatis infection, especially considering the slower and more gradual onset of their symptoms.

There is ongoing debate regarding the most effective antibiotic treatment for these infections. Some options include topical tetracycline ointment to be applied four times a day for six weeks, oral doxycycline to be taken twice a day for one to two weeks, oral azithromycin with a single dose of 1 gram followed by 500 mg orally for two days, or oral erythromycin to be taken four times a day for one week.