Always be suspicious of AK in patients who wear contact lenses or present with eye injuries, especially when in contact with soil or water.

Early diagnosis is crucial for better outcomes and the wrong medications, such as steroids, exacerbate AK. Steroids can increase the number of trophozoites and promote encystment. Additionally, they suppress the immune system, making it even harder for the body to fight off the infection.

Contact lens wearers may delay seeking help being used to minor irritations. Even with mild visible symptoms suspect AK until ruled out. Refer your patient for a second opinion if you are unsure of the diagnosis.

AK is painful, debilitating and can lead to blindness.

Unfortunately, statistics show that up to 80% of AK patients worldwide are being misdiagnosed amongst others with herpetic, bacterial, viral, or fungal keratitis. Be aware that AK and fungal infection can also present with an intact epithelium (stromal keratitis). Over 38% from the misdiagnosed AK cases are Herpes Simplex Virus (HSV) and 20% are bacterial infection. This can lead to the administration of steroids, worsening the AK infection.

Misdiagnosis of AK, can have serious consequences, especially if steroids have been prescribed. Healthcare providers should be vigilant to avoid delays in treatment and thoroughly investigate corneal inflammation to ensure optimal patient outcomes.

AK IS A MUST ON YOUR RADAR
DON’T START STEROIDS UNLESS AK IS RULED OUT!

This is because steroids increase the number of trophozoites and promote encystment. As cysts are extremely resistant to a toxic environment, this will make AK treatment even more difficult, leading to longer and more problematic therapies with poorer outcomes. Additionally, steroids suppress the immune system, making it harder for the body to fight off the infection.

In the early stages, the clinical signs of AK may include grey-dirty epithelium, pseudodendritiformic epitheliopathy, perineuritis, multifocal stromal infiltrates and ring infiltrate. It is important to note that AK can be confused with Herpes Simplex Virus (HSV) due to its pseudodendritiformic appearance with grey epithelial opacities, often resembling dendritic or geographic HSV. However, in AK, epithelial defects lack terminal bulbs.

Please rule out AK before you confirm Herpes Simplex Virus (HSV)

In the advanced stages, AK can resemble bacterial or fungal keratitis. What differentiates AK from these infections are multifocal, dot-like, partly transparent infiltrates. Mycotic or bacterial stromal infiltrates are typically monofocal and thicker; however, satellite infiltrates in mycotic keratitis can occasionally resemble AK infiltrates. Corneal ring infiltrates, which may also occur in bacterial and fungal infections, can confound the clinical diagnosis. The above-mentioned differences in appearance of infiltrates and more common epithelial defects in AK should aid in identifying the correct diagnosis. Furthermore, the presence of perineural stromal infiltrates is strongly suggestive of AK.

The sooner you as a healthcare professional seek expert advice or refer the patient to a specialist, the better the chances of achieving the best possible outcome for your patient.

AK IS A MUST ON YOUR RADAR
DON’T START STEROIDS UNLESS AK IS RULED OUT!

Always suspect AK in contact lens wearers, in cases of ocular trauma involving water or dirt, and in patients who have recently been diagnosed with another type of keratitis (Herpes Simplex Virus/HSV) and are not responding to treatment.

There is no standard protocol for diagnosing AK. The clinical picture of the eye and the patient is an essential factor, as is the experience of the clinician and the equipment available.

The sooner you can confirm AK the better the chances for your patient.

Everyday counts! Do not delay referral if you find an unclear clinical situation, to ensure the best help for your patient.

• Symptoms out of proportion to clinical presentation
• Patients with AK often have pain that is disproportionate to the findings, but there are also cases with little or no pain. The eye may show only slight redness and mild superficial disease or keratitis.
• Any contact with water or dirt
• No improvement with standard antiviral, antibacterial or antifungal therapies
• A ring-shaped stromal infiltrate may present in later disease.

HISTORY

It is very important to find out the history of your patient for the last 1-2 months.

These are some of the most important questions and they do not take long for a doctor to ask:

• Have you showered while wearing your contact lenses?
• Have you exposed your contact lenses to water when bathing, swimming or engaging in any water sports?
• Have you experienced eye irritation from dirt, sand, gardening or other odd jobs?
• Have you washed or stored your contact lenses in water or old solution?
• Have you washed and always made sure that your hands were thoroughly dry before handling your contact lenses?
• Have you worn your contact lenses for longer than the recommended hours in a row or while sleeping?

Always suspect AK in contact lens patients until proven otherwise.

AK IS A MUST ON YOUR RADAR
DON’T START STEROIDS UNLESS AK IS RULED OUT!

CLINICAL TESTS

The following tests are reliable for positive AK results but be aware that a negative result for AK could be false.

IVCM (In Vivo Confocal Microscopy) is a non-invasive imaging technique that needs to be performed by an experienced operator to ensure accurate and immediate test results. Here are some guidelines to follow when using IVCM.

PCR (Polymerase Chain Reaction) of corneal scrapings  is a diagnostic test that can provide results within 60 minutes. However, it is worth noting that PCR can be negative even when it is AK. The accuracy percentage of PCR varies vastly. As an example of how to conduct a PCR, Sydney Eye Hospital has produced an animated video that effectively illustrates their culture protocol. We encourage you to take a look at it.

In vitro culture using Escherichia coli (E. coli) is a diagnostic test that gives results within 3 weeks.

An AK patient has no energy, the eye cannot stop tearing, the sinuses, head and jaw are hurting, the body is trying to fight the infection and the inflammation. The patient is coping with excruciating pain, sleep deprivation and a mind that is spinning. Hiding in a completely dark room, they feel depressed, isolated from the world for weeks or even months, thinking they will never get their normal lives back. They miss taking part in daily activities with family and friends and are unable to enjoy sunlight for many months. All of this is accompanied by anxiety and worry about their vision. Many of them end up with medical PTSD, afraid of relapse, water, traumatized by the intensity of the treatments and procedures.

Daily life with AK is dictated by the drop regime and the many medical appointments. Some patients may suffer side effects from the strong medication. Not only does AK affect the eye, the body and the mind, but it also affects the job situation as well as the family life. Additionally, in many cases it is difficult to get the right medication and/or the costs are not covered.

For many AK patients there are aftermaths like glaucoma, dry eyes, loss of depth perception, inability to drive in the night, disfigurement, vision loss, trigeminal nerve pain, loss of the eye as an organ and more. To get the appropriate help several surgeries might be necessary.

AK patients often appreciate specific and personal help. Showing your support can make a huge difference to their journey towards healing.

• Make time for them and offer answers to their questions.
• Ask how they are doing and find out if they need help with daily tasks.
• Offer to refer them to a counsellor (mental health support) if necessary.
• Discuss possible pain management strategies, including referral to a pain specialist if necessary.
• Explain the initial focus and what to expect next. Give some perspective regarding time and outcome, including the high probability that this can change at any time.
• Inform their companion how this illness affects the whole person and that the patient depends on extra support from family or friends.
• Refer them to this Acanthamoeba Keratitis Eye Foundation website that provides useful information and helpful tips for daily life when dealing with AK.
• Encourage AK patients to join a support group, so they do not feel alone and can share their experiences with others who have been or are going through the same journey. In the support group, we welcome not only AK patients, family, friends, but also health care professionals.

It is important for patients to understand that your primary goal is to eradicate the parasite.

This can be a lengthy process, often taking anywhere from 6 to 26 months or more. Only when the infection has been fully treated does the focus shift to restoring the patient’s vision, if possible.

Diagnosed with a serious and rare disease your patient has probably the wish to learn more about this condition and to connect with other AK patients. Offer them high quality sources of information about AK and make the possibility to access a support group known to them. These groups provide a lot of practical tips and support.

If you are uncertain about how to engage with your patient, you might want to try this interactive game. As a doctor, you'll encounter 15 diverse scenarios across different levels, allowing you to hone your skills in best practices and empathy when communicating with patients. This educational serious game has been developed by the French rare disease network, SENSGENE. Its goal is to raise awareness among healthcare professionals of all ages and specialties about best practices and the importance of empathy in delivering diagnoses for rare diseases.

Since an AK-therapy / AAT (Anti-amoebic Therapy) is very aggressive the start of the treatment requires proof (IVCM, PCR, culture, biopsy) and a very experienced corneal specialist.

Therapeutic epithelial debridement/abrasion is done to reduce the infected tissue and to give the drops a better chance of penetration.

The current non-standardized treatment of AK involves the use of topical antimicrobial agents such as biguanides, PHMB 0.02%, PHMB 0.04%, PHMB 0.06%, PHMB 0,08%, Chlorhexidine, in combination with aromatic diamidines such as propamidine isethionate, dibromopropamidine, and neomycin. Unfortunately, propamidine and hexamidine may not be easily accessible in all countries, creating challenges for AK patients seeking the necessary treatment.

Treating AK usually involves applying drops every hour, around the clock, during the initial days. Subsequently, the drops are used every waking hour for several weeks, followed by a gradual reduction if there is progress, while closely monitoring the eye’s response. However, individual specialists may have their own methods.

In severe situations, AK patients may be given oral medications such as Miltefosine (Impavido) or Voriconazole.

Ongoing research focuses on new AK medicines and therapies.

In 2024, polyhexanide /PHMB 0,08% (Akantior) became the first evidence-based treatment for AK to be approved by the EMA and EC in Europe.

Medical therapies (drops, oral medication) should be the first line of treatment for AK. Unfortunately, 16-25% of AK cases do not respond to medical therapy. Early therapeutic corneal transplantation, whether partial or full thickness, can play a crucial role in these situations. By physically removing infected corneal tissue, the procedure helps to "debulk" the infection load, which can be critical in limiting the spread of the parasite. This approach can potentially slow or halt disease progression and make other treatments (such as antimicrobial or antiparasitic agents) more effective.

Early DALK is a highly promising new approach to eliminate the amoeba with a much better graft survival rate than PKP. However, this technique requires a very experienced expert.

To prevent the reinfection of the donor graft, Map biopsies of the cornea are used to effectively remove corneal tissues infested with acanthamoeba cysts.

During eye surgeries, especially corneal transplants or procedures to remove infected tissue, ophthalmologists should be careful to avoid pushing any amoeba deeper into the eye, which could worsen the infection or lead to severe complications, such as vision loss.

Despite the preparation costs, the benefits often justify their use, especially in complex cases. Autologous serum drops closely mimic the natural tear film, providing a non-inflammatory, biocompatible alternative that promotes healing without the addition of preservatives that may further irritate the cornea. For patients suffering from AK, these drops can provide much-needed relief and significantly aid in the corneal healing process.

AK patients frequently explore unconventional therapies. Known to our foundation are:

Cryotherapy is also known as cryosurgery. This freezing and thawing process results in the death and regression of unwanted cells.

Tea tree oil is a natural remedy. It is known for its anti-inflammatory and antibacterial properties, which can help reduce inflammation and prevent infection. While there is limited scientific research on the effectiveness of tea tree oil for AK, some AK patients have reported positive results from using the scent of this essential oil.

Ivermectin: accessible in low-income countries where other medicines are difficult or almost impossible to obtain. (Patient input)

Pentamidine: Treatment with intravenous pentamidine prior to therapeutic keratoplasty.

In order to provide the best possible care for your patient and improve their quality of life (QoL), a multidisciplinary team should be involved as from the start.

This team may include: local ophthalmologists, cornea specialists, pain specialists, infectious disease specialists, general practitioners and psychological professionals.

By working together, they can provide a comprehensive approach, addressing both the physical and emotional needs of their patient.

For AK patients, the possibility of a relapse can be a major concern. It is not uncommon for patients to experience a relapse when their medication has been stopped or reduced too quickly.

As the AK progression shows many variations and the AAT is very aggressive, relapses and setbacks such as cataracts, iris damage, high IOP, recurrent epi defects, corneal melting, etc. are a reality. Close monitoring and a realistic perspective can give the patient some confidence.

Additionally, inform them that they can always contact you or your team if they have any questions. Providing a phone number or email will empower the patient to take control of their own journey.

AK eyes go through a lot and have therefore a higher sensibility and are susceptible to develop toxicity reactions. Preservative-free eye drops are preferable during treatment for AK and its aftermath, if available.

Despite successful treatment, patients may face complications and secondary diseases.

Common problems experienced with AK include trigeminal nerve pain, cataracts, glaucoma, dry eye, loss of vision, severe ocular inflammation and medical PTSD.

Unfortunately, regardless of medical treatment, 41% of AK cases eventually require a corneal surgery.

A rare but painful variation of AK is Acanthamoeba scleritis (ASK), which affects about 10–18% of AK patients.

There is a high enucleation rate of 6%. Some AK patients choose to have their eye removed.

Other possible consequences are: limbal stem cell deficiency (LSCD), extreme low eye pressure, retinal detachment, optic nerve damage, astigmatism, diplopia (double vision), chorioretinitis, corneal perforation, iris irregularity (Atrophy, Dyscoria, Corectopia, or Synechiae), Charles Bonnet Syndrome, neovascularization, neurotrophic keratopathy, oedema, retro corneal membrane, scarred cornea, recurrent epi defects, vitreous opacity, deficiency in ciliary body, droopy eyelids, liver or kidney problems due to medication, and dental problems due to steroids.

Collaborating with a general practitioner is essential to prevent complications from systemic therapies by monitoring liver and kidney function.

Hence, regular blood tests are recommended when treatment includes oral medications. For systemic anti-amoebic therapies, weekly monitoring of liver and kidney function is advised.

Glaucoma is a frequent complication and requires high attention to avoid irreversible damage to the optic nerve. Often a combination of several glaucoma drops, and high doses of acetazolamide are necessary to control high IOP. Discuss with your patient whether they can tolerate the severe side effects to save their optic nerve and consider CPC (Cyclophotocoagulation) during active infection.

You might need to decide whether an eye with severe or unknown glaucoma history is worth the risk of transplantation, but you cannot see the optic nerve through the dense scarring. The Purkinje entoptic test can provide predictive value in this situation.

There is a minimal risk, that the acanthamoeba could penetrate intraocular and cause a systemic infection.

The pain that AK patients go through can only be understood by other AK patients. It is so debilitating and excruciating, that if they were to put a number on it, it would be a 10 out of 10 – and they are not exaggerating.

Our advice to healthcare professionals is to listen carefully to their patients. Patients often feel that they are neither heard nor believed because the clinical picture does not correlate with the severity of the pain.

AK patients can experience different types of pains:

• Eating pain, meaning when the amoeba ‘eats’ the cornea – it is an excruciating, debilitating pain; AK patients want to grab a fork and rip out their eye.
• Burning pain, right after putting the drops in or dull, lingering pain from constant use of the drops.
• Stabbing / shooting pain related to the trigeminal nerve area.
• Light sensitivity pain leads to complete intolerance of any light and the continuous blinding tires and incapacitates.

Patients may also experience headaches, sinus, tooth and jaw pain, trigeminal nerve pain, high IOP pain, throbbing pain, skin sensitivity, muscle spasms around the eye and forehead, toxicity pain, sensitivity to sound and touch, nausea, sweating, rapid heartbeat and fatigue.

It is important to refer the patient to a pain management specialist right from the start.

For most AK patients, ordinary pain killers are far from adequate. Medicine differentiates two different types of pain with AK:

1. nociceptive pain (i.e. active pain which is acute or reversible) during active infection characterized by throbbing, burning, sharp/shooting, and sensitivity to light.
2. persistent neuropathic or neuroplastic pain (i.e. pain associated with nerve damage which is often persistent and non-reversible) is described as shooting or aching pain associated with the trigeminal nerve region.

A nerve modulator such as Pregabaline, Carbamazepine amongst others can help block the trigeminal neuralgia pain.

A patient going through AK is not just having an eye infection: there is fear by not knowing what will happen; the loss of vision; the nonstop eye drops interrupting every task, meal, conversation and thought; the lack of sleep; the excruciating pain; the isolation due to light sensitivity; the hiding in the dark longing for sunshine; the types of treatments they are put through; life standing still and the fear of water for months or years. AK patients feel mistreated, when not being understood or taken seriously in their situation, and may suffer trauma from this serious eye injury, which affects the vital sense of sight.

Medical PTSD, or medical trauma-related post-traumatic stress disorder, is a form of PTSD triggered by traumatic experiences in medical settings. It can develop in patients who have endured intense, life-threatening, or distressing medical events—such as severe illness, painful procedures, long hospitalizations, or sudden diagnoses. Medical professionals themselves can also experience medical PTSD due to repeated exposure to traumatic situations.

Medical PTSD can be triggered by various experiences, including:

• Critical or life-threatening illnesses: For example, cancer diagnoses, heart attacks, or severe infections.
• Invasive or painful medical procedures: Surgeries, ventilations, or emergency treatments can be overwhelming and distressing.
• Intensive care stays: ICU settings can be traumatic due to high-stress environments, limited mobility, and frightening equipment like ventilators.
• Medical errors or adverse events: If a patient experiences harm or near-harm due to a medical error, it can be highly distressing.
• Chronic pain or disability: Ongoing health issues can lead to cumulative stress and trauma.

The symptoms of medical PTSD are similar to PTSD from other types of trauma and can include:

• Re-experiencing the event through flashbacks, intrusive thoughts, or nightmares related to the medical experience.
• Avoidance behaviors such as avoiding locations and situations associated with the trauma.
• Hypervigilance and anxiety, with symptoms like difficulty sleeping, irritability, and feeling constantly on edge.
• Negative changes in mood and cognition, such as feeling detached, hopeless, or overly negative about one’s health or the future.

Medical PTSD can complicate a patient’s recovery and adherence to future medical care. Avoidance refusal of necessary treatments, ultimately impacting overall health outcomes. It also affects mental health, potentially leading to depression, anxiety, or other trauma-related conditions.

Treatment for medical PTSD may include:

• Trauma-focused therapy: Cognitive-behavioral therapy (CBT) or Eye Movement Desensitization and Reprocessing (EMDR) can help patients process traumatic medical experiences.
• Medication: In some cases, antidepressants or anti-anxiety medications are used to manage symptoms.
• Support groups or peer support: Engaging with others who have experienced similar trauma can be beneficial.
• Mindfulness and relaxation techniques: These can reduce stress and help with symptom management.

Overall, recognizing and addressing medical PTSD is essential for supporting both mental and physical healing in patients and can improve their engagement with future medical care.

More information

1. Offer to refer them to a psychological professional, as well as encourage them to join a Support Group.
2. Help them to additional information and useful tips on how to manage AK in daily life and encourage self-advocacy. You are welcome to share the link to this website akeyefoundation.com