 Hi, good morning. My name is Bala Ambari. I work at Marin Eye Center. And I'd like to chat with you today about eye infections and the red eye. So I'm going to start with covering things that can cause iridiness from the front of the eye and work our way backward. So we're going to start first with the conjunctiva, which is the skin, then the cornea. Look at the tissues around the eye and then go inside the eye. So this is a classic example of a very common cause of red eye. This is a subconjunctival hemorrhage. If you had to have something wrong with your eye, you would pick this. This is benign. It will not affect your vision. It will not hurt the eye. But it does look ugly. And the patient should be reassured that it will go away on its own, usually within 10 to 14 days. And it might change colors before it goes away. It might spread like water on a table before it goes away. But it will go away. Things to think about if somebody is having subconjunctival hemorrhage frequently include hypertension, constipation, anticoagulants, trauma, altitude sickness. And so if somebody is having these episodes frequently, it's best to ask about these things, check of blood pressure, and so on. Next, let's talk about viral conjunctivitis. This occurs due to the same viruses that cause colds, adenoviruses, enteroviruses, and so on. They can get into the eye and cause inflammation of the conjunctiva, the skin of the eye. This is frequently associated with having a preceding cold or upper respiratory infection or being around someone who did. There's usually a course of one to two weeks of itching, pain, tenderness, tearing, and redness. There can be redness throughout the eye, discharge, some small patechia or small little hemorrhages on the conjunctiva, and also lymph nodes on the neck. If the cornea is involved, this is not as benign. This becomes what's called epidemic keratoconjunctivitis, EKC, so that's much more severe. So let's show you some pictures of how these things can look like. So on this initial picture, we have flipped the eyelid. And what you'll notice is that there's small little pinpoint patechia on the tarsal conjunctiva. There's also a good number of follicles or bumps or lymphatic collections on the conjunctiva. With this picture, if you look closely, you'll see those follicles are substantially bigger. This is on the inferior conjunctiva. And then on the bulbar conjunctiva on the eye itself, you can see some small areas of subconch hemorrhage as well as diffuse injection. And that's important. If there's sexual injection, it's less likely to be this viral disease tends to be diffuse. As the disease progresses, you can see seromucous discharge, either on the upper lid or in the lower lid. And then this is what I was referring to as EKC, where there are white spots on the cornea. Any time there are new white spots on the cornea, that's not a good sign. And here, these white spots are what are called subepithelial infiltrates. They're due to an autoimmune reaction to the virus or immunologic reaction to the virus. I should say immunologic, not autoimmune. And they will go away, but they can have a prolonged course. Typical viral conjunctivitis goes away in a couple of weeks. But if you have EKC, it can take months for it to completely resolve. And in this particular patient, you'll notice that the infiltrates are within the pupil, so they can easily cause glare and affect the vision. Patients with viral conjunctivitis are contagious, as long as they're clinically symptomatic. You should advise them to wash their hands frequently and not to shake other people's hands. Treatment for it is fairly benign. Cold compresses and artificial tears, as it is self-limited. Very important, tell them to not touch the other eye if it's not infected. No reason to give the other eye the infection. And very important, tell your primary care colleagues and your optometry colleagues not to give topical steroids. Topical steroids will make a patient feel better, but they will extend the course dramatically and really prolong the course of resolution. Further, topical steroids can open the door to other and more serious infections, such as virus or bacteria. One of the most common conditions that can imitate viral conjunctivitis is allergy. Allergy is distinguished by both symptoms and signs. Allergy usually has more itch than pain and more chemosis or swelling of the conjunctiva rather than injection. Generally, allergy is more symmetric than viral. Viral is often asymmetric. Allergy typically affects both eyes symmetrically, with the only exception being if there's a splash to one eye, which is usually pretty evident, self-evident on history. Treatment is pretty much the same. Cold compresses and artificial tears, the only difference is you can actually treat the allergy with patinol, olopatidine or zadotaur or any of the other topical antihistamines. Again, avoid steroids and also avoid the vasoconstrictors, the epinephrens, the phenolephrens, the vasocon, the naphcon that cause the eye to constricted splabdustles but can have rebound redness. So here's an example of allergic conjunctivitis. So this example of allergic conjunctivitis shows that patient has chemosis. You can see the swelling of the conjunctiva, much more so than redness. There's also the classic allergic shiners or dark spots or dark circles around the eyes due to the itching. And if you flip the eyelid on somebody with severe allergy, you can see large papillae. This is an example of severe allergy called giant papillary conjunctivitis due to contact lens overwear. And so contact lenses can be a cause of allergy due to the proteins that are building up on the contact lens surface. And in anyone who has contact lenses, it's important to flip their eyelids open at least once a year. Just as in the hospital, if you don't check a temperature, you won't find a fever. If you won't flip the eyelid, you won't see what's going on underneath the eyelid. Very important, contact lens patients get their undersurface of the eyelid examined at least yearly. Next up in the conjunctival inflammation category is bacterial disease. Usually this isn't children. It's less common in adults. But it can occur still in adults. The main flora that cause bacterial conjunctivitis are staphylococcus and streptococcus, either pyogenes or strep pneumonia. In patients where there's not H influenza vaccine, H influenza can cause bacterial conjunctivitis as well. This is very easy to diagnose because there's an obvious pus coming out of the eye, an obvious purulent discharge. Treatment is with antibiotic ointment for usually a week or two. So here's an example of a purulent discharge in both eyes. One particular kind of bacterial conjunctivitis that is very bad is gonorrheal conjunctivitis. Because gonorrhea can eat the cornea for lunch and the retina for dinner. It's very progressive, very rapidly perforating. This generally occurs either in newborns or in sexually active persons. And what are the giveaways for this are there are lymph nodes just behind the ear, pre-auricular adenopathy. The course is very severe. The patient might wake up feeling fine, but by noon have very severe redness and pain. And there's a lot of pus. On Gramstein, you would see gram negative cocci. And on treatment, you should give both topical treatment, antibiotic drops, anointment, as well as a systemic treatment, intramuscular seftrioxone. In general, anytime there's a question of gonorrhea, there's often a question of chlamydia. So it's advisable to do both seftrioxone and doxycycline, as well as refer the patient to the appropriate health authorities so that their partners can get evaluated. Now what happens if somebody has conjunctivitis for a long time or more than a month, then that falls into the chronic conjunctivitis category. This can be due to problems with the eyelid margin, blufferitis, it can be due to problems with the lacrimal system if the lacrimal sac is blocked. So if you press on the lacrimal sac and it's painful, that can cause a dachryocystitis, which can spill over into the conjunctiva. And it can be due to chlamydia. Chlamydial serotypes vary depending on the region. In the US, adult inclusion conjunctivitis is due to serotypes D through K. There can be contact of the eye with infected secretions, such as swimming pool or genital urinary secretions. It can also cause pre-uricular adenopathy or nodes behind the ear. But it's not as severe and it's less acute than adenoviral or gonadial disease. Treatment is with dr. cyclin. These are examples of adult inclusion conjunctivitis, where you have small little inclusion cysts on the conjunctiva. Now in Africa, in much of the third world, the chlamydial serotypes are much more serious, much more severe. And those are usually A, B, and C. And they can cause trochoma. Trochoma can lead to conjunctival scarring underneath the eyelid. You can see these bumps or fibrous nodules on the tarsal conjunctiva, as well as eventually the formation of arlt slides, which are a reticular or lacy ridges of fibrous tissues. And you can imagine when you have these scar tissue bumps on the under surface of the eye, what happens to this person's cornea every time they blink? That can be very damaging to the cornea and that can cause trochoma. And again, that's generally serotypes A, B, and C. It's very common in Africa in much of the third world. And it's transmitted just by fomites, just by contact. And the corneal scarring can be blinding. It's one of the leading causes of corneal blindness around the world. If it's diagnosed early, dr. cyclin for two weeks, erythromycin, if the patient is a child or a pregnant or a nursing woman, are alternatives. And then it might be a surgical treatment to fix the eyelid and also perhaps the cornea. If there's cornea transplant tissue available, a cornea transplant can be done after the eyelid is fixed. The eyelid is not fixed. Doing a cornea transplant in this type of situation will almost certainly fail because the new cornea will also get rubbed and damaged by the scar tissue underneath the eyelid. Last part of conjunctivitis is what happens in babies. Neonatal conjunctivitis has a differential diagnosis of four pathogens or four conditions, I should say. Chlamydia, herpes, gonorrhea, and silver nitrate. And in babies, the important thing to bear in mind is that, sorry, let me go back here. The important thing to bear in mind when you're examining a baby with conjunctivitis is timing. If it occurs on the day of birth or the day after birth, you think about silver nitrate. If it occurs on day two or three, you think about gonorrhea. If it's happening in a week or two after birth, that most likely causes chlamydia. Herpes can occur at any time, but generally the mother will have a history of general herpes and the doctor will be aware of that. Okay, so that's it for the conjunctiva. Let's look at the periorbital and preceptile tissues. Those can get infected. You can get superficial skin infection of the eyelid and surrounding area. And this is generally due to upper respiratory flora, so same culprits, staph, pneumococcus, strep pyogenes. There can also be contributions from an infected lacrimal sac or chalazion or a sty where there's a blocked mybomian gland in the lid that can bleed to a cellulitis as well. Here's an example of a cellulitis surrounding a chalazion. So the technical term would be a hordiolum, H-O-R-D-E-O-L-U-M, which is the area of redness surrounding that central chalazion. Treatment is the following. If you have a chalazion, obviously, drain it. Warm compresses are good for both necrosis status and chalazions or chalazia. Oral antibiotics can include sefton, augmentin, cufflex, anything that covers those upper respiratory flora. Look very carefully for orbital cellulitis signs, and we're gonna talk a bit about what are giveaways for orbital cellulitis. If there's any question of orbital disease, admit the patient to the hospital and give them IV antibiotics. If there's any problems with lacrimal drainage, have the plastics team evaluate the patient. Orbital cellulitis is more severe and more threatening because it can damage the optic nerve, can damage the muscles surrounding the eye. The clinical signs of orbital compartment syndrome, and remember that the orbit is a fixed volume of space, so if there's a mass of infection behind the eye that will press on the eye and press on the optic nerve, the clinical signs of those include proptosis where the eye is being pushed forward, loss of vision, loss of color vision, an afferent pupillary defect or an APD in the affected eye, and pain on eye motion or inability to move the eye in certain directions. So let's look at this picture. When you examine this picture, your eye is drawn to the young lady's left upper eyelid, and you see this large mass of redness. But what's more important, take a step back. Look at this as a forest for the trees. What's more important is that that left eye is lower than the right eye. So if you look at the position of the two eyes, you should be able to see that the left eye is physically lower than the right eye. That means that something is pushing that left eye down, and that's the more serious finding on this picture. That's what you should look for in any patient, not just being drawn to the obvious area of problem of the redness, but looking at the picture as a whole at the forest for the trees. A CAT scan or MRI is essential. IV antibiotics and surgical evaluation should be conducted and surgery could be by the oculoplastics team or by the ENT team. Make sure that whoever is checking out the patient looks inside the sinuses. And if somebody is diabetic or immunocompromised or an acidosis, there's a high risk that orbital cellulitis is being caused by mucor. Mucor mycosis is a very serious fungus that will eat the eye for lunch and the brain for dinner. It's very bad. And so if somebody does have mucor, they need aggressive surgery, IV amphotericin, and treatment of the underlying condition, the immunocompromised or the acidosis or the diabetes or all of those. All right, let's take a look at another patient with orbital cellulitis. Now, somebody walks in. You might get a call from the emergency room saying that there's this patient who can't see. Now you might go down and see that their vision, they can actually read. The reason that the ER doc told you that they can't see is that they forgot to lift the eyelid. So first thing is educate your colleagues about lifting the eyelid to look at the eye. Now, let's look at this picture more carefully. What you'll notice is a few things. One is that the eye position on the left eye is pushed down and out. The pupil is slightly larger and that it's very red and kemotic. On this picture, you see the evidence that the eye motion is restricted, that the eye is not moving when the other eye is being asked to move. On CT scan, you can easily see that nasal orbital abscess with air cells as well as a nasal sinusitis. And very important, look at the structure of the eye globe, of the globe. It's being pushed. The sclera is being indented by that abscess. This person needs drainage. On the coronal cut, you'll see a lot of maxillary sinusitis as well, a lot of maxillary liquid and abscess. So this person should definitely go to surgery as soon as possible, but sometimes your ENT colleague might be out playing golf or not available or something like that. To buy time, what you can do, this is not the same patient, but a different patient with a similar condition is to drain the pus in the maxillary sinus by sticking a needle. So if you have a clear area of abscess that is accessible with needle drainage, this can buy you 12 hours, 24 hours, enough time for the surgical team to come. All right, so we've talked about conjunctiva, we've talked about the eyelids. Let's start going into the actual structures of the eye. Oh, sorry. Can I get some more? Should I keep going? Go for it. So now let's start talking about the cornea. Corneal infections can occur from a variety of pathogens as far as bacteria that can penetrate the intact epithelium that are forked. Gonorrhea, pseudomonas, diphtheria and listeria. One of the biggest risk factors for corneal infection is contact lenses. And so contact lenses can be bad because they block oxygen from the air to get into the cornea. And remember, the cornea normally doesn't have blood vessels. It relies on the air for oxygen. Contact lenses can cause mechanical rubbing against the cornea and provide a base for bacteria to grow. And so all of those things, blocking of oxygen, mechanical rubbing and providing a base for bacteria, all of those are bad for the cornea because the cornea is naturally, as you recall, a vascular and therefore more vulnerable to infections. Here's an example of a white infiltrate in the midprophal cornea, which is a corneal ulcer. And on the gram stain, what you see is not just the mucus, but also gram positive cocci in clusters. This is a staphylococcal infection. This is a more severe infection where you have not just a large corneal ulcer in the central cornea, there's also a hypopion or pus in the anterior chamber. And it looks like the center of that ulcer is close to perforation. Gram stain shows gram negative rods. This was a pseudomonas infection. The definition of a corneal ulcer is epithelial defect plus infiltrate. Contact lenses can cause just an epithelial defect or abrasion. They can cause superficial punctate carotopathy or diffuse epithelial damage or a corneal ulcer. If there's just epithelial disease after a contact lens, but no infiltrate, three or four times a day of antibiotics is sufficient. But if there's an actual infiltrate, if there's a bacterial infection, then the patient needs hourly antibiotics. This can be o-floxacin or moxifloxacin, four times a day, polysporin, erythromycin, tobromycin, whatever your antibiotic ointment of choice is. If the patient is not getting better within 48 hours or so, or if you're really concerned that this is a bad infection, then you can start or switch to fortified antibiotics. That can include various combinations such as cephazolin and tobromycin, or the strongest fortifieds would include vancomycin and amicazin. When do you culture? You don't have to culture every corny ulcer. You should culture if there's an unusual history, if the patient is not getting better, if there's only one eye, if the ulcer is large, if it's central, or if there's lots of anterior chambers cell or a hypopia. But most ulcers don't fall into these categories. So most of the time you can treat empirically. If there's a history of MRSA on the patient, start with vancomycin drops. If there's an animal scratch, like a cat or a dog, those creatures often have pastorella and so it's advisable to give the patient some oral augmentin as well. Fungal infection of the cornea, fungal disease is very common in Africa due to agricultural nature of the population. And if plant matter gets into the eye, that can easily trigger an infection by fungi. Very common fungi include candida, aspergillus, and fusarium. But this really varies depending on the region of the world that you're in. Even within a country, different regions can have different fungi. So really take some time to learn about what the local fungal elements are in your particular hospital or region. The main elements of clinical diagnosis of fungal keratitis is feathery borders or irregular borders. Most bacterial ulcers are sharply demarcated. Fungal lesions tend to have satellite lesions as well as endothelial plaques. Treatment is topical amphotericin, topical voriconazole, topical nadomycin, those are your three main antifungal treatments that can be given topically. Amphotericin, nadomycin, or voriconazole. There's an example of a very bad fungal infection with the feathery borders. I should also note oral agents that can be given include itraconazole and fluconazole. Those can be used supplementally as an oral antifungal as well. That patient who you just saw needed their cornea removed and on the pathology you see all of these diffuse large hyphae on the cornea. Now one thing to, one thing to note is that if you have access to a corneal confocal microscope you can actually see these hyphae on the confocal and so you can actually visualize that without taking out corneal tissue. We've done bacteria, we've done fungi in the cornea. Let's talk about herpes. This is a virus that can affect any part of the eye, blepharitis, conjunctivitis, keratitis. It can present either at the same time as other areas of herpes or reactivate in the cornea by itself. And risk factors for reactivation are many. Sun exposure, stress, menstrual periods, cold wind, immunosuppression, and even minor trauma. Here's an example of herpes affecting both the eyelid and the temporal conjunctiva. So this is a blepharoconjunctivitis where you have vesicles and sectoral injection. And this is an example of a herpetic dendrite which is on the cornea. You see a branching pattern with terminal bulbs. This is stained by rosebengal. It can be stained by fluorescein just as well. This is a more aggressive dendrite and here we're using fluorescein staining. And if the patient is not treated or if the patient is treated with steroids inappropriately, these dendrites can get confluent and cause geographic ulcers which are very difficult to manage. Here's an example of a horrible geographic ulcer which is challenging to treat and to save the patient's vision. So things to be aware of. On the skin, herpes disease has vesicles on an arithematous base. On the cornea, we talked about the dendrites that are associated with epithelial defect and infiltrate. Chronic herpes on the cornea destroys the nerves and that causes decreased corneal sensation. So very often these patients are not in that much pain. It can cause melting or thinning of the stroma and if it affects the inside of the eye, it can affect the aureus and trabecular mesh work leading to high pressure and photophobia. Sometimes you can have a pure stromal keratitis due to an immune reaction against the herpes. There there will be no epithelial defect. It'll just be a stromal infiltrate. And usually that stromal infiltrate is coin shaped in configuration and in the mid-stroma. Treatment. Now this has evolved a bit. The classical treatment was viroptic ointment plus oral acyclovir. Viroptic is getting increasingly hard to find. Zirgan gel, which is gansychlovir gel, came out a few years ago and that can be done five times a day. If there's epithelian involvement in addition to the viroptic drops or the acyclovir ointment whether there's zirgan gel or the vidarabine, then in addition to the antiviral treatment, one should also give some topical acuflox or ophloxacin to prevent a bacterial super infection. If there's melting, if there's thinning of the corneal stroma, we wanna first prevent additional thinning. So the patient might need glue. They might need madroxyprogesterone drops to prevent collagenes. Oral vitamin C, one gram four times a day. Doxocycline is also an anti-collagenes. They may need a bandage contact lens or a torsorophy and you really wanna keep that melting from getting worse. You wanna follow that patient very carefully and closely. If they have stromal disease, then not only do they need antiviral coverage, but they should get some topical steroid drops, spread four times a day or something like that. But if there's any epithelial defect at all, don't give steroids until the epithelial defect is closed. If there's increased pressure or arthritis, they definitely need some steroids to control the intraocular inflammation. Now, when do we need to give oral acyclovir? In my practice, I pretty much give it routinely because there's not any major downside. The head study, the herpetic eye disease study, showed that acyclovir is useful if there's recurrent herpetic disease, because this will prevent future recurrences, or if there's stromal disease or intraocular disease. But for first-time epithelial keratitis, if you don't feel like giving oral acyclovir, you don't have to. Vericella zoster is also herpes virus. It can cause chickenpox in childhood or shingles or zoster in adulthood. Chickenpox rarely affects the eye. If it does, you can give diarrhea ointment. Shingles often affects the V1 distribution, the ophthalmic branch of the trigeminal nerve. Generally, the eye itself is spared with zoster, but it can sometimes be affected either in the cornea or in the intraocular structures. One of the key signs that point towards risk for ocular involvement in zoster is Hutchinson sign, where if the tip of the nose is involved, that means the nasociliary nerve is involved. And the nasociliary nerve supplies both the tip of the nose and the cornea. So if you have shingle vesicles in the tip of the nose, really pay attention to that cornea very carefully. The classic finding of shingles or zoster ophthalmicus is respect for the dermatomal distribution, so the midline is respected. And on the eye, you can see pseudodendrites where you have elevated lesions without terminal bulbs. Also, you can get decreased corneal sensation. So here's an example of a pretty severe shingles episode, respecting the midline, causing edema of the eyelid. If there's no ocular involvement, oral antivirals are sufficient, encyclovir, famcyclovir, or valacyclovir. If you treat the patient within three days of onset, then you're helping them in terms of reducing not just the time of duration of the disease, but also reducing the risk of future post-heropatic neuralgia. Also remember that these shingles lesions on the skin can get infected, so give the patient some antibiotic appointment as well. If there is ocular involvement, give the patient some antibiotic eye drops, remove the pseudodendrites, and really consider if there's any herpes simplex at all. If you think there might be, then start bioptic. If the patient is immunocompromised, they have HIV or leukemia or something else that's causing immunocompromise, give the patient IVA cyclovir. Now after shingles episodes, patients can often have pain in the area that's called, that chronic pain is called post-heropatic neuralgia, can cause very severe problems by disrupting sleep, by causing chronic pain and even depression. So you wanna get on this, don't just blow this off, just because the skin looks normal doesn't mean that the patient isn't in pain. So we do give the patient low doses of oral antidepressants. My favorite is nortryptoline or disipramine, just a low dose, 20 milligrams at night that will help take the edge off the pain and help them sleep. Capsacean cream to the affected area of the skin can be very helpful. And then if you need more than that, then you're getting into chronic pain management with Tegretal or Gabapentin, which is Neurontin or other Lyrica or other chronic pain conditions, which are best managed by a pain specialist. Chronic shingles can cause dryness of the cornea. So take care of that with lubrication, bench contact lens, punctal plug if necessary. Okay, so we've done the cornea, we've done congenitiva, we've done eyelids, can have an infection inside the eye that can cause severe redness, that's endophthalmitis. The most common cause is after cataract surgery, but it's very unusual after cataract surgery. There's probably one in 3,000, one in 5,000 risk after cataract surgery, but there's so many cataracts done that cataracts are the most common cause in endophthalmitis. Other causes include glaucoma surgery, trauma, endogenous, and here you have severe redness and severe pain that does not respond to properocaine. Most of everything else I've told you about gets better with topical anesthetic. In addition, they have cells, hypopia, loss of the red reflex, and clouding of the cornea. These patients might need IV antibiotics, intravitral antibiotics, or vitrectomy. The flora of endophthalmitis depends on whether it's early after surgery, late after surgery, whether it's following trauma where bacillus can be a cause, following glaucoma surgery where pneumococcus or H-influenza can be a cause, or if it's endogenous. Endogenous endophthalmitis is often due to fungus in the context of immunocompromise, or if they have a chronic indwelling catheter. And I think I'll stop there. So we'll just forget that last picture. Okay, I'll just stop after endophthalmitis. Is there anything that you want to say to close out? Sure, so to close out, red eye can be due to non-infectious conditions like allergy, like blepharitis, daeparyocystitis, can be due to severe infections of the conjunctiva, or of the cornea, or of the surrounding tissues, or infection inside the eye. We'll do a separate lecture on non-infectious inflammations of the eye, UVitis, that's a whole other topic, that'll be a separate lecture. But anytime you see a red eye, the most common causes are allergy, sinusitis, blepharitis, daeparyocystitis, or infections of the cornea, or infections inside the eye. And I hope I've given you a framework and strategy for diagnosing and managing these. Thank you.