Always consider Acanthamoeba keratitis (AK) risk for contact lens wearers or those with eye injuries, especially from soil or water contact. AK may cause severe pain with mild visible symptoms. Contact lens wearers may delay seeking help, so doctors should suspect AK until ruled out. Seek a second opinion if diagnosis is uncertain. AK is painful, debilitating, and can lead to blindness. Early diagnosis is crucial for better outcomes.

When it comes to properly diagnose AK, unfortunately, statistics show that around 69% of AK Warriors worldwide are being misdiagnosed amongst others herpes, bacterial, viral, or fungal pathogens. Even more concerning is that over 38% of AK cases are misdiagnosed as herpes simplex, this can lead to the administration of corticoids and steroids, worsening the infection and the situation, and 20% as bacterial infection.

It is crucial to ensure that AK infection is ruled out before prescribing steroids. This is because steroids can increase the number of trophozoites and promote encystment. Additionally, steroids can suppress the immune system, making it more challenging for the body to fight off the infection.

Misdiagnosis of Acanthamoeba, especially in contact lens users, can lead to severe 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.

In the early stages, AK can be confused with Herpes Simplex Virus (HSV) due to a pseudodendritiformic appearance with grey epithelial opacities, often resembling dendritic or geographic HSV. However, in AK, the 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 health care professional seek expert advice or refer the patient to a specialist, the better the chances of the best possible outcome for your patient.

The first and most important step when it comes to diagnosis is to always suspect AK in contact lens wearers as well as patients who have recently been diagnosed with another type of keratitis and are not responding to therapy.

Each AK patient has their own course of the disease. For some it might start relatively mildly, for others it is extreme from the beginning.

For an AK diagnosis, there is no standard approach. The clinical picture of the eye and the patient are an essential factor, as are the experience of the clinician and the equipment available.

• Symptoms out of proportion to clinical signs
• No improvement with standard antiviral, antibacterial, or antifungal therapies
• Can present as a ring-shaped stromal infiltrate in later disease.

HISTORY

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

These are some of the most important questions and do not take long for a doctor to ask. Always suspect AK in contact lens patients until proven otherwise.

Some important questions to ask include:

• Have you taken a shower wearing your contact lenses?
• Have you exposed your contact lenses to water while bathing, swimming, or engaging in any water sports?
• Have you experienced any irritation of your eye by dirt, sand, etc... or while gardening?
• 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 more than 12 consecutive hours or while sleeping?

CLINICAL TESTS

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

PCR (Polymerase Chain Reaction) of corneal scrapings is a diagnostic test that may provide results within 60 minutes. However, it’s worth mentioning that PCR can be negative even when it is AK. The accuracy percentage of PCR varies vastly.

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

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

It is important for patients to understand that the primary goal of their healthcare professional team will be to eradicate the parasite. This can be a lengthy process, taking anywhere from three to eighteen months or more. Only once the infection has been fully treated, can the team begin to focus on restoring the patient’s vision if possible.

In order to provide the best possible care to patients, a multidisciplinary team should be involved. This team may consist of local ophthalmologists, corneal specialists, pain specialists, infectious disease specialists, general practitioners, and psychological professionals. By working together, they can provide a comprehensive approach to care, addressing both the physical and emotional needs of their patients.

An AK Warrior has no energy, the eye cannot stop tearing, the sinus, head and jaw are hurting, the body is trying to fight the infection and the inflammation. The patient is coping with the excruciating pain, deprivation of sleep and a mind that is spinning. While 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 life back. They miss taking part in daily activities with family and friends and are unable to enjoy sunlight for many months. All this is accompanied by anxiety and worry about their vision. Many of them end up with medical PTSD, afraid of a relapse, water, traumatized by the intensity of the treatments and procedures.

Their daily life is dictated by the drop regime and the many medical appointments. Some patients might suffer side effects from the strong medication. AK does not only affect the eye, the body and the mind, but also affects the job situation as well as the family life; and let’s not forget that many times it is difficult to get the right medication and/or the costs are not covered.

And for many there are aftermaths like glaucoma, dry eyes, no depth perception, not being able to drive in the night, disfigured appearance, vision loss, trigeminal nerve pain, loss of eye as an organ and more.

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

• Set aside some time for them and offer answers to their questions.
• Ask how they are doing and find out if they need help with daily tasks or psychological support.
• Discuss possible pain management strategies.
• Offer to refer them to an expert if necessary.
• Explain the first focus and what to expect next, give some perspective regarding time and outcome including the high probability that this can change 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 site, where they can find useful information and helpful tips for daily life when dealing with AK.
• Encourage them to join a support group, so the AK Warrior does not feel alone and can share their experience with others who have been or are on the same journey. In the support group we welcome not only the AK Warriors, family, friends, but also eye professionals, opticians, optometrists, ophthalmologists, corneal specialists, researchers, psychological professionals and any others that want to understand the impact of AK and learn from the patient’s perspective.

Official standardized protocols for treating AK are not yet available. Ongoing research is focusing on new drugs and therapies. The current non-standardized treatment for AK involves using topical antimicrobial agents like biguanides, PHMB 0.02%, PHMB 0.04%, PHMB 0.06%, 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.

AK Warriors 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 to reduce inflammation and prevent infection. While there is limited scientific research on the effectiveness of tea tree oil for AK, some individuals have reported positive results from using the scent of this essential oil.

For an AK Warrior (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.

It is important to keep in mind that every patient is unique, and what works for one patient may not work for another. This is why the exchange of expertise between different corneal specialists can be incredibly valuable. By working together, specialists can share knowledge and experience to provide the best possible care for their patients.

AK can lead to complications and aftermaths. A rare but painful variation of AK is Acanthamoeba scleritis (ASK), which affects around 10–18% of patients. In extremely rare cases, the acanthamoeba can cause a systemic infection beyond the eye, even causing granulomatous Acanthamoeba encephalitis (GAE) of the brain.

Unfortunately, regardless of medical treatment 41% of AK cases eventually require a corneal surgical procedure. Despite successful treatment, patients can have complications and secondary diseases. There is a high enucleation rate of 6%. So some AK patients choose to remove their eye.

Some of the common symptoms that AK Warriors have experienced include trigeminal nerve pain, cataract, dry eye, severe eye inflammation, and medical PTSD. There were also other possible effects such as limbal stem cell damage, extreme high (glaucoma) or low eye pressure, retinal detachment, liver problems due to medication, optic nerve damage, corneal perforation, loss of vision or eye, 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, and dental problems due to steroids.

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

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

AK Warriors describe the pain as follows:

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

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

AK Warriors will experience two different types of pain:

• Nociceptive pain during active infection
• Neuropathic pain after the infection has been resolved.

Nociceptive pain can begin mildly or can hit the patient right from the beginning with severe pain, is important to refer the patient to a pain management specialist right from the start. For most, ordinary over-the-counter pain killers are usually far from adequate.

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

Neuropathic pain presents as a shooting or aching pain linked to the trigeminal nerve area, which exhausts the AK Warriors.

A patient going through AK is not just having an eye infection: there is the fear of not knowing what will happen; the loss of vision; the nonstop eye dropping interrupting every task, meal, talk and thought; the lack of sleep; the excruciating pain; the isolation due to light sensitivity; hiding in the dark longing for sunshine; life standing still and the fear of water. AK Warriors feel mistreated, when not being understood or taken seriously in their situation and may suffer trauma due to the type of treatments they are put through.

Offer them the opportunity for referral to a psychological professional, as well as encourage them to join a Support Group.

Provide them with the foundation page for additional information and useful tips to support them throughout their journey and encourage self-advocacy.