Foreign Body in the Eye
Foreign body in the eye
A foreign body in the eye is present when particles such as sand, awns or splinters adhere to or penetrate the conjunctiva or cornea. It leads to Pain, severe tearing, blinking and possibly corneal damage. If left untreated, inflammation, ulcerAn ulcer is an open wound or erosion of the skin or mucous membrane that often heals poorly and can be caused by a variety of factors, including infections and chronic inflammatory conditions. and vision loss threaten.
Foreign bodies in the eye in dogs and cats are a common ophthalmological emergency. These are foreign objects that can penetrate into various structures of the eye. The eye of our pets is a complex sensorySensory refers to the senses or perception. Sensory systems in dogs and cats include sight, hearing, smell, taste, and touch, all of which are central to interacting with their environment. organ that is protected from external influences by several natural protective mechanisms such as eyelids, eyelashes, tear fluid and the blink reflex. The anatomyAnatomy is the scientific study of the structure of living things. It deals with the construction and organization of organisms, including their systems, organs, and tissues. of the animal eye differs in some aspects from the human eye, which must be taken into account when considering eye injuries. For example, dogs and cats have a third nictitating membraneThe nictitating membrane, also called the third eyelid, is a protective membrane in the inner corner of the eye in dogs and cats. It provides additional protection and moistening of the eye. (membrana nictitans), which serves as additional protectionProtection refers to safeguarding against diseases or harm. In veterinary medicine, this can include protecting animals through vaccinations, the use of parasite control products, or providing a safe environment., but can also be affected by foreign bodies themselves.
Foreign bodies can lie superficially on the conjunctiva or cornea, be located under the eyelid or the nictitating membraneThe nictitating membrane, also called the third eyelid, is a protective membrane in the inner corner of the eye in dogs and cats. It provides additional protection and moistening of the eye., or penetrate into deeper structures of the eye. Depending on the location, type of foreign body and duration of stay in the eye, damage of varying severity can occur. Animals with protruding eyes such as brachycephalic breeds (e.g. pug, Persian cat) are particularly at risk, as their eyes are less protected by the bony orbital cavityThe orbital cavity is a bony structure in the skull that surrounds the eye and its adnexa. It protects the eye and provides attachment points for the eye muscles..
Causes
Foreign bodies can easily get into the eye. Smaller foreign bodies are flushed out by the tear fluid and blinking alone and do not require treatment.
Foreign bodies include in particular:
- Insects
- Grains of sand
- Plant parts
More detailed:
The causes of foreign bodies in the eye are varied and strongly related to the animal’s living environment and activities. The most common foreign bodies include:
Organic materials such as blades of grass, awns, plant parts, wood splinters or insects pose a particular hazard, as they often carry bacteriaBacteria are microscopic, single-celled organisms that exist in almost every environment on Earth. Some types of bacteria are beneficial or even essential to life, while others can cause disease. or fungal spores and can therefore cause infections in addition to mechanical damage. These foreign bodies occur particularly frequently in spring and summer, when dogs roam through tall grass or rummage in the undergrowth.
Inorganic materials such as grains of sand, dust, pebbles or metal splinters can also get into the eye, especially when driving with the window open or in windy conditions. These particles often cause scratches on the cornea, which can lead to serious complications if left untreated.
Chemical substances such as cleaning agents, fertilizers or other household chemicals can get into the eye if handled improperly and cause severe burns. Particular caution is required here, as the damage is often more serious than with mechanical foreign bodies.
Breed-specific factors also play a role. Dog and cat breeds with protruding eyes or flat faces (brachycephalic breeds) have an increased risk of a foreign body in the eye, as their eyes are less protected by the skull structure. In addition, some breeds such as Cocker Spaniels or Bloodhounds have drooping eyelids, which can promote the penetrationPenetration describes the entry or permeation of a substance or organism into a body or material. In medicine, it can refer to the penetration of microorganisms into tissues or the insertion of instruments into the body. of foreign bodies.
Symptoms
Foreign body in the eye in dogs and cats
Typical Symptoms:
- Sudden blinking/squinting,
- Rubbing
- Tears of the eye
- Conjunctival HyperemiaHyperemia refers to an increased blood volume in a body area, often as a reaction to inflammation or as a result of improved blood circulation. It can lead to redness and a feeling of warmth in the affected area.
- Keeping the eye closed
- Sensitivity to light, possibly visible foreign body
- Corneal surface rough/cloudy
Alarm signs:
If the foreign body penetrates the structures of the eye, the symptoms intensify and it comes to
- Severe pain, corneal opacity or visible defect (ulcerAn ulcer is an open wound or erosion of the skin or mucous membrane that often heals poorly and can be caused by a variety of factors, including infections and chronic inflammatory conditions.)
- PurulentPurulent refers to pus or the production of pus, which may indicate a bacterial infection. Purulent inflammatory conditions are often painful and may have significant swelling and redness. discharge, significant Swelling
- Foreign body stuck (e.g. awn)
- Pupil change, vision deterioration
Escalation/course:
- Superficial irritation can turn into Ulzeration within hours
- Increasing discharge/pain after 6–24 h → infectionAn infection is the colonization and multiplication of pathogens such as bacteria, viruses, fungi, or parasites in an organism, which often, but not always, leads to a disease./ulcer more likely
- Deep injury → risk of perforationA perforation is a rupture or hole in the wall of a hollow organ, such as the gastrointestinal tract or bladder, which can lead to the release of contents into the body and severe infection. Perforations are Emergencies that require rapid veterinary intervention in dogs and cats., especially with persistentPersistent means lasting or continuing for an extended period. In veterinary medicine, it can refer to chronic diseases or symptoms that do not subside. rubbing
The symptoms of foreign bodies in the eye can vary depending on the type, size and location of the foreign body, but are usually clearly recognizable. One of the classic signs is increased tearing (epiphora), which is a natural reaction of the body to flush out the foreign body. The conjunctiva often appears reddened and inflamed (conjunctivitis), which is due to the irritation caused by the foreign body.
Affected animals often show noticeable blinking or keep the eye partially or completely closed (blepharospasm) to reduce Pain and avoid further irritation. Typically, they try to rub the affected eye with their paw or rub their head on furniture or the floor, which often makes the situation worse and can lead to additional injuries.
If a foreign body remains for a longer period of time, the symptoms can worsen. There may be significant Swelling of the eyelids (blepharitis), and the cornea may become cloudy (keratitis). In advanced cases, purulentPurulent refers to pus or the production of pus, which may indicate a bacterial infection. Purulent inflammatory conditions are often painful and may have significant swelling and redness. secretion can form, indicating a bacterial secondary infectionA secondary infection occurs when an already weakened individual suffers an additional infection, often because the immune system is impaired by the primary infection.. Particularly in the case of perforating foreign bodies, inflammation of the inner eye structures (uveitis) can occur, recognizable by a change in pupil size or shape and a discoloration of the irisThe iris is the colored part of the eye that surrounds the pupil. It consists of muscle tissue and adjusts the size of the pupil through its contraction or relaxation to regulate the amount of light that enters the eye..
Some animals may also experience increased sensitivity to light (photophobia) and specifically seek out darker areas. In severe cases, the animal may show signs of general malaise, such as reduced appetite or reduced activity, especially if Pain is severe or an infectionAn infection is the colonization and multiplication of pathogens such as bacteria, viruses, fungi, or parasites in an organism, which often, but not always, leads to a disease. is present.
First Aid
- Wash your hands with soap and water.
- If the foreign body is larger and you can see it clearly, such as a blade of grass in the area of the conjunctiva, you can try to grasp it and remove it or flush it out with warm water. Here, too, a sterile packaged syringe can be helpful, with which you repeatedly draw up slightly warm, clean tap water and flush it into the eye under gentle pressure.
- Try to keep your pet’s eyelids open.
- Do not rub the eye, do not put pressure on the eyeball and do not use any objects to remove a foreign body from the eye.
- Prevent your pet from rubbing its eye with its paws. Use a collar if necessary.
When should you see a vet sooner?
Urgency changes from orange to → red if there is a visible perforationA perforation is a rupture or hole in the wall of a hollow organ, such as the gastrointestinal tract or bladder, which can lead to the release of contents into the body and severe infection. Perforations are Emergencies that require rapid veterinary intervention in dogs and cats., severe Bleeding, globe prolapseProlapse refers to the falling out or protrusion of an organ or part of it from its normal position, often through an opening. In animals, this can include, for example, a rectal mucosal prolapse or a vaginal prolapse., or severe traumaA trauma refers to a physical injury or damage caused by external force. Traumas can range from simple cuts to severe multiple injuries..
If you notice a lodged foreign body, a distinctly red eye, a significantly inflamed conjunctiva, or purulentPurulent refers to pus or the production of pus, which may indicate a bacterial infection. Purulent inflammatory conditions are often painful and may have significant swelling and redness. discharge in the corner of the eye, an immediate, careful, professional examination of the eyes is also necessary (Fig.).
Diagnosis
The diagnosisA diagnosis is the identification of a disease or condition by its symptoms and/or results from diagnostic tests. It is the first step in the management and treatment of patients. of foreign bodies in the eye requires a thorough ophthalmological examination. First, the veterinarian performs a general assessment of the affected eye, paying attention to signs such as redness, Swelling, discharge, and blepharospasm. To allow a detailed examination, a local anestheticAn anesthetic is a drug used to induce insensitivity to pain. There are various forms, including local, regional, and general anesthetics, depending on their method of application and desired effect. in the form of eye drops is often administered, which relieves the Pain and allows the animal to open the eye.
Slit-lamp examination is an essential diagnostic tool that allows an enlarged, three-dimensional view of the eye. With this technique, even the smallest foreign bodies or injuries to the cornea can be identified. A fluorescein dye test is often performed to assess corneal integrity. A fluorescent dye is applied to the eye, which adheres to damaged areas of the cornea and glows green under blue light. This method is particularly valuable for detecting corneal injuries caused by foreign bodies.
If a deeper foreign body is suspected or in more complex cases, further imaging procedures such as ultrasoundUltrasound refers to sound waves that are above the hearing threshold of the human ear. In medicine, ultrasound is used for diagnostic imaging procedures to visualize internal organs, tissues, and blood flow. or, in specialized facilities, even optical coherence tomography (OCT) can be used. These methods allow a detailed representation of the inner eye structures and can help in the localization of foreign bodies that are not visible superficially.
In some cases, especially if an infectionAn infection is the colonization and multiplication of pathogens such as bacteria, viruses, fungi, or parasites in an organism, which often, but not always, leads to a disease. is suspected, swabs can be taken for microbiological examination. This is important to identify the causative pathogenA pathogen is a microorganism or virus that can cause disease in its host. Pathogens include bacteria, viruses, fungi, and parasites. and initiate targeted antibiotic therapyTherapy refers to the treatment of diseases or disorders with the aim of alleviating symptoms, promoting healing, or improving quality of life. Therapies can be medicinal, surgical, or through other medical interventions.. The diagnosisA diagnosis is the identification of a disease or condition by its symptoms and/or results from diagnostic tests. It is the first step in the management and treatment of patients. must also take into account differential diagnoses such as primaryPrimary refers to the first or original cause of a disease or condition, as opposed to secondary causes or symptoms that develop from it. conjunctivitis, allergic reactions or other eye diseases that can cause similar symptoms.
Further veterinary measures
Introduce your animal to a veterinarian.
Superficial foreign bodies can usually be removed under local anesthesiaAnesthesia refers to the state of insensitivity to pain and can be partial (local anesthesia) or for the entire body (general anesthesia). It is used to keep patients pain-free during surgical procedures.. Foreign bodies that have penetrated into the interior of the eye must be removed surgically.
The treatment of foreign bodies in the eye depends on the type, size and location of the foreign body as well as the extent of the damage caused. In the case of superficial foreign bodies on the conjunctiva or cornea, the first measure is careful removal. This is done in the veterinary practice under local anestheticAn anesthetic is a drug used to induce insensitivity to pain. There are various forms, including local, regional, and general anesthetics, depending on their method of application and desired effect. using special instruments such as moist cotton swabs, fine tweezers or irrigation with sterile saline solution. For deeper-seated or larger foreign bodies, sedationSedation refers to the state of calming or suppressing the central nervous system with medication, which reduces anxiety and irritability and sometimes induces a light sleep. or general anesthesia may be necessary to ensure safe removal.
After the removal of the foreign body, drug therapyTherapy refers to the treatment of diseases or disorders with the aim of alleviating symptoms, promoting healing, or improving quality of life. Therapies can be medicinal, surgical, or through other medical interventions. is usually carried out to prevent secondary infections and promote healing. Antibiotic eye drops or ointments are prescribed to prevent or treat bacterial infections. In the case of severe Inflammatory conditions, anti-inflammatory drugsAnti-inflammatory drugs are medications that reduce inflammation. They can be divided into nonsteroidal anti-inflammatory drugs (NSAIDs) and corticosteroids and are used in dogs and cats to reduce Inflammatory conditions and Pain. such as corticosteroidsCorticosteroids are a class of steroid hormones that occur naturally in the body and can also be produced synthetically. They have anti-inflammatory and immunosuppressive properties and are used in veterinary medicine to treat a variety of conditions. can also be used, but these must be used with caution, especially in the case of existing corneal defects.
Pain management is an important aspect of therapyTherapy refers to the treatment of diseases or disorders with the aim of alleviating symptoms, promoting healing, or improving quality of life. Therapies can be medicinal, surgical, or through other medical interventions.. In addition to local anesthetics for examination and removal of the foreign body, systemic painkillers can be prescribed to provide relief to the animal. In some cases, a neck brace is recommended to prevent the animal from rubbing its eye and causing further damage.
For perforating injuries or foreign bodies that have penetrated deeper structures of the eye, a surgical intervention may be necessary. These procedures are ideally performed by a veterinary ophthalmologyOphthalmology is the branch of medicine that deals with the diagnosis, treatment, and prevention of eye diseases. Veterinary ophthalmology concerns the eye health of animals, including dogs and cats. specialist. Depending on the severity of the injury, a corneal suture, conjunctival flap surgery, or, in severe cases, even removal of the eye (enucleationEnucleation is the surgical procedure to remove an eyeball. This may be necessary in cases of severe eye disease, injury, or Tumors to relieve Pain and protect the animal's health.) may be necessary if it can no longer be saved.
Prognosis and aftercare
The prognosis for foreign bodies in the eye depends largely on several factors: the type and size of the foreign body, the duration of its stay in the eye, the depth of the injury and the speed of veterinary care. Superficial foreign bodies that are removed early generally have an excellent prognosis. The cornea has a remarkable ability to regenerate, and small superficial injuries often heal completely within a few days without leaving any permanent damage.
However, deeper injuries or prolonged retention of the foreign body can lead to complications. Corneal scars can remain and, depending on their location and extent, impair vision. Especially in the case of infections with aggressive pathogens or in the case of foreign bodies that release chemical substances, healing can be delayed and the risk of permanent damage increases.
Aftercare plays a crucial role in the success of healing. Regular check-ups with the veterinarian are important to monitor the healing process and adjust the therapyTherapy refers to the treatment of diseases or disorders with the aim of alleviating symptoms, promoting healing, or improving quality of life. Therapies can be medicinal, surgical, or through other medical interventions. if necessary. The correct administration of the prescribed medication is essential – eye drops or ointments usually have to be applied several times a day, which can be a challenge for pet owners. A precise instruction on the correct technique of drug administration is therefore important.
During the healing phase, the animal should be protected from further injuries. A neck brace prevents the animal from scratching the eye, and activities that could increase the risk of renewed eye injuries should be restricted. For brachycephalic breeds or animals with recurring eye problems, long-term preventive measures such as regular eye check-ups and special care measures may be recommended.
Summary
Foreign body in the eye is a common ophthalmologyOphthalmology is the branch of medicine that deals with the diagnosis, treatment, and prevention of eye diseases. Veterinary ophthalmology concerns the eye health of animals, including dogs and cats. emergency in dogs and cats that requires quick action. The range of possible foreign bodies ranges from harmless dust particles to dangerous perforating objects such as thorns or metal splinters. Typical symptoms include increased tearing, Conjunctival hyperemiaHyperemia refers to an increased blood volume in a body area, often as a reaction to inflammation or as a result of improved blood circulation. It can lead to redness and a feeling of warmth in the affected area., squinting, and partially or completely keeping the eye closed. If a foreign body remains for a longer period of time, the symptoms can worsen to Swelling, corneal opacity, and purulentPurulent refers to pus or the production of pus, which may indicate a bacterial infection. Purulent inflammatory conditions are often painful and may have significant swelling and redness. discharge.
Diagnostic clarification by a veterinarian is essential and includes a thorough eye examination, often supported by special techniques such as the fluorescein test or slit lampA slit lamp is a special microscope used in veterinary ophthalmology to examine the anterior structures of the eye in detail, including the cornea, the iris, and the lens. Examination with a slit lamp can aid in the diagnosis of eye diseases in dogs and cats. examination. The TherapyTherapy refers to the treatment of diseases or disorders with the aim of alleviating symptoms, promoting healing, or improving quality of life. Therapies can be medicinal, surgical, or through other medical interventions. depends on the type and location of the foreign body and ranges from simple removal under local anesthesiaAnesthesia refers to the state of insensitivity to pain and can be partial (local anesthesia) or for the entire body (general anesthesia). It is used to keep patients pain-free during surgical procedures. to complex surgical procedures for deeper foreign bodies. A subsequent drug treatment with antibiotics and anti-inflammatory agents is necessary in most cases.
The PrognosisThe prognosis is the prediction of the likely course and outcome of a disease based on the general state of health, the nature of the disease, and the response to treatment. It can provide information on how a disease is expected to develop. is mostly good with early treatment, with the healing time depending on the severity of the injury. Careful aftercare with regular medication and protectionProtection refers to safeguarding against diseases or harm. In veterinary medicine, this can include protecting animals through vaccinations, the use of parasite control products, or providing a safe environment. from further injury is crucial for a full recovery. Preventive measures such as avoiding high-risk situations and regular eye check-ups can help prevent future incidents.
Outlook on current research
Veterinary research in ophthalmologyOphthalmology is the branch of medicine that deals with the diagnosis, treatment, and prevention of eye diseases. Veterinary ophthalmology concerns the eye health of animals, including dogs and cats. is continuously advancing, which also affects the treatment of foreign bodies in the eye. Innovative imaging techniques such as high-resolution optical coherence tomography (OCT) enable more precise diagnostics and localization of foreign bodies, especially in the case of deeper or very small objects. This technology, originally developed in human medicine, is increasingly finding its way into specialized veterinary facilities and significantly improves diagnostic capabilities.
In the field of TherapyTherapy refers to the treatment of diseases or disorders with the aim of alleviating symptoms, promoting healing, or improving quality of life. Therapies can be medicinal, surgical, or through other medical interventions., new biomaterials are being researched that can serve as temporary or permanent corneal substitutes. These could be used in the future for severe injuries caused by foreign bodies to repair the cornea and maintain vision. The development of special contact lenses for animals is also progressing. These can not only serve as protectionProtection refers to safeguarding against diseases or harm. In veterinary medicine, this can include protecting animals through vaccinations, the use of parasite control products, or providing a safe environment. for the healing cornea, but also as carriers for drugs that are continuously released over a longer period of time.
Research into regenerative therapies, including the use of stem cells and growth factors, shows promising results in the treatment of corneal injuries. These approaches could shorten healing time and reduce the risk of Scar tissue formation in the future. Furthermore, new antibiotics and anti-inflammatory substances are being developed that are more specific and cause fewer side effects.
Another important area of research is the development of preventive measures, especially for predisposed breeds. This includes both improved protective devices for animals at increased risk and genetic studies aimed at reducing the breeding of animals with extreme anatomical features that can lead to eye problems.
Frequently asked questions (FAQs)
- How do I recognize if my pet has a foreign body in its eye?
Look for increased tearing, redness of the eye, frequent blinking, rubbing the eye with the paw, or a partially or completely closed eye. These symptoms indicate Pain or discomfort and should be taken seriously. - Can I remove a visible foreign body from my pet’s eye myself?
In the case of superficial, easily visible foreign bodies, you can try to remove them by carefully rinsing with lukewarm, sterile saline solution. However, never use tweezers or other instruments and do not put pressure on the eyeball. In case of Uncertainty / disorientation or if the foreign body is not easy to remove, seek veterinary help immediately. - How urgent is a visit to the vet if a foreign body is suspected in the eye?
A foreign body in the eye should be considered an emergency. The longer a foreign body remains in the eye, the greater the risk of complications such as infections or permanent damage. Therefore, seek veterinary help within hours if possible. - Which breeds are particularly susceptible to foreign bodies in the eye?
Brachycephalic breeds such as pugs, bulldogs, Persian cats or Pekingese have an increased risk due to their protruding eyes and flat face shape. Dog breeds with drooping eyelids such as Cocker Spaniels or Bloodhounds are also more susceptible to foreign bodies under the eyelids. - How long does healing take after a foreign body has been removed from the eye?
The healing period depends on the severity of the injury. Superficial scratches often heal within 3–5 days, while deeper injuries or infections can take weeks to heal completely. Regular follow-up checks with the veterinarian are important to monitor the healing process. - Can an untreated foreign body in the eye lead to blindness?
Yes, untreated foreign bodies can lead to serious complications such as corneal ulcers, infections or inflammation of the inner eye structures, which can potentially lead to blindness. - How do I administer eye drops correctly to my pet?
Gently fix your pet’s head, pull the lower eyelid down slightly and drip the prescribed amount into the resulting conjunctival sac, not directly onto the cornea. Avoid touching the dropper tip with the eye or fur to prevent contaminationContamination refers to the pollution of surfaces, objects, water, food, or air with harmful microorganisms, chemicals, or other hazardous substances.. - How can I prevent foreign bodies in my pet’s eye?
Avoid driving with the windows wide open, keep your pet back in strong winds or dusty environments, and check their eyes regularly, especially after walks through tall grass or undergrowth. Regular eye care may be useful for predisposed breeds. - Are certain seasons particularly risky for foreign bodies in the eye?
Yes, there is an increased risk in spring and summer due to grasses, pollen and insects. Grass awns, which can easily get caught in the eye, are particularly dangerous. In autumn, seeds and dry plant parts can be problematic, while in winter road salt and grit can cause eye irritation. - Can my animal fully recover after a foreign body injury to the eye?
With early and appropriate treatment, the prognosisThe prognosis is the prediction of the likely course and outcome of a disease based on the general state of health, the nature of the disease, and the response to treatment. It can provide information on how a disease is expected to develop. for a full recovery is good for most foreign body injuries. Even if scars remain on the cornea, they often do not significantly impair vision, provided they are not located directly in the visual center.
Literature
- Professional Association of Ophthalmologists of Germany e. V., & German Ophthalmological Society e. V. (2011). Guideline No. 8: Injuries to the eye and its adnexa (with modification regarding burns in February 2024).
- Featherstone, H. J., & Heinrich, C. L. (2021). Ophthalmic examination and diagnostics. In K. N. Gelatt, G. Ben-Shlomo, B. C. Gilger, D. V. H. Hendrix, T. J. Kern & C. E. Plummer (Hrsg.), Veterinary ophthalmology (6. Aufl., S. 533–613). Wiley-Blackwell.
- Gelatt, K. N. (2013). Veterinary ophthalmology (5. Aufl.). Wiley-Blackwell.
- Gould, D., & McLellan, G. J. (2022). BSAVA manual of canine and feline ophthalmology (4. Aufl.). British Small Animal Veterinary Association.
- Ledbetter, E. C., & Gilger, B. C. (2021). Diseases and surgery of the canine cornea and sclera. In K. N. Gelatt, G. Ben-Shlomo, B. C. Gilger, D. V. H. Hendrix, T. J. Kern & C. E. Plummer (Hrsg.), Veterinary ophthalmology (6. Aufl., S. 1082–1164). Wiley-Blackwell.
- Löwe, G., & Löwe, O. (2021). Notfälle bei Hund und Katze – Ein tierärztlicher Ratgeber (208 S.). Kynos-Verlag.
- Maggs, D. J., Miller, P. E., & Ofri, R. (2017). Slatter’s fundamentals of veterinary ophthalmology (6. Aufl.). Elsevier.
- Merck & Co. (2020). Merck veterinary manual (11th ed.). Merck Publishing.