0:00 Hello, in this video, we're going to talk about orbital cellulitis and periorb 0:08 ital cellulitis. 0:11 Orbital cellulitis is a serious potentially life-threatening infection 0:14 involving the 0:14 contents of the orbit, the space where your eyeball sits. 0:19 Orbital cellulitis includes inflammation of fat and extraocular muscles, the 0:24 muscles 0:24 that move your eyes. It must be distinguished from periorbital cellulitis, 0:30 sometimes called 0:31 preseptal cellulitis, which is an infection of the front part of the eyelid and 0:37 is not 0:37 as serious as orbital cellulitis. Neither of these infections actually involve 0:43 the eye 0:43 globe itself. 0:46 Orbital cellulitis is an ophthalmic emergency because of the risk of vision 0:52 loss and extension 0:53 to other structures, including the cavernous sinus. Essentially, it can lead to 0:59 thrombosis, 0:59 clots, and even death. 1:02 Let's first talk and learn about the anatomy. 1:10 The orbit is a cone-shaped structure, lying horizontally with its apex in the 1:16 skull. 1:17 The orbit is surrounded by para-nasal sinuses. These are namely the frontal sin 1:22 us, lying 1:23 superiorly, ethmoid, medially, and maxillary sinuses inferiorly. 1:33 The ethmoid sinuses are separated from the orbit by a paper-thin layer called l 1:38 aminar 1:38 paparesia, which contains many perforations for nerves and blood vessels, as 1:44 well as some 1:45 natural fenestrations, which is termed zucker-candles dehiscences. 1:53 The most common root of infection of the orbit is by extension from the ethmoid 2:01 sinuses, 2:02 likely facilitated through these perforations. 2:11 The main anatomy to know is that the superior and inferior orbital veins drain 2:17 blood directly 2:18 into what's called the cavernous sinus. 2:22 Because of this communication, and because the inferior orbital veins are valve 2:26 less and 2:26 have no valves to prevent back flow, infections can pass really easily from the 2:32 orbit and 2:33 lead to cavernous sinus syndrome, and other infections within the skull itself. 2:42 So, let's compare the differences between orbital, cellulitis, and peri-orbital 2:49 cellulitis. 2:51 Orbital cellulitis is an acute infection involving the contents of the orbit 2:56 and is an ophthalmic 2:57 emergency. 3:00 Bacterial rhinocinocidosis is the most common cause of orbital cellulitis. 3:04 Infection of the sinus can lead to perforation and extension of the bacterial 3:04 infection from 3:10 the ethmoid sinuses, most commonly, leading to orbital cellulitis. 3:16 Other potential causes include ophthalmic surgeries, peri-bulber anesthesia, 3:21 where local 3:22 anesthetic is really put around the eye within the orbit, orbital trauma with a 3:27 fracture 3:27 or foreign body, dachryosisitis, infection of the teeth, middle ear or face can 3:34 also 3:34 extend into the orbit. 3:41 The causative organism of orbital cellulitis are often difficult to identify, 3:45 but the most 3:46 commonly identified pathogens are really those such as staphylococcus aureus 3:51 and streptococci 3:53 species, and others also include hemophilus influenza and anaerobic bacteria. 4:03 Peri-orbital cellulitis, also termed preseptal cellulitis, is infection of the 4:10 eyelid and 4:11 surrounding skin and tissue, anterior to the orbital septum. 4:17 It is typically milder than orbital cellulitis, and it may follow infection of 4:22 adjacent structures, 4:23 also such as seen in dacharyocystitis or trauma. 4:28 The causative organisms are really quite similar to orbital cellulitis, 4:32 including staphylococcus 4:34 aureus, as well as streptococcus species. 4:43 Looking at the clinical features, both orbital cellulitis and preseptal cellul 4:47 itis cause oculopane 4:49 and eyelid swelling with erythema. 4:56 The orbital cellulitis causes swelling and inflammation of extra ocular muscles 5:00 and fatty 5:01 tissue within the orbit, and this will lead to pain with eye movement and propt 5:06 osis, which 5:07 is essentially eyeball popping out. 5:10 Infection of the ocular muscles can lead to ophthalmoplegia, because 5:13 inflammation of 5:14 the eye muscles will cause weakness of that muscle. 5:23 Cell also have reduced visual acuity and even visual loss in orbital cellulitis 5:28 , but it does 5:29 not occur in peri-orbital cellulitis. 5:33 The vision loss associated with orbital cellulitis is thought to result from 5:37 any of the following 5:38 processes. 5:40 Number one, optic neuritis, which is inflammation of the optic nerve caused by 5:45 nearby infection, 5:47 ischemia resulting from thromboflobitis along the orbital vein, and also 5:53 pressure resulting 5:54 in central retinal artery occlusion. 6:04 The infection in orbital cellulitis, because it's deeper, it can extend. 6:09 It can create abscesses in the orbit and subperiostium, essentially within the 6:15 bone. 6:16 Fluents can extend to the brain, the meninges, and as mentioned, the cavernous 6:21 sinus. 6:21 In the cavernous sinus, it can cause inflammation of some other cranial nerves, 6:27 leading to bilateral 6:28 cranial nerve palsies. 6:35 Chemosis is also more common in orbital cellulitis. 6:38 Fever's and high-neutral-filled count is more common in orbital cellulitis. 6:44 Evidence of orbital cellulitis may develop rapidly. 6:48 Therefore, close monitoring is indicated with daily checks of visual acuity and 6:52 assessment 6:53 of pupillary-light reflex. 6:55 A sluggish or absent pupillary-light reflex or a relative afferent pupillary 7:01 defect indicates 7:01 optic nerve involvement. 7:08 Diagnosis The diagnosis of orbital cellulitis versus peri-orbital 7:12 cellulitis is a clinical diagnosis with support gold-standard by imaging. 7:20 Although both peri-orbital cellulitis and orbital cellulitis typically cause 7:25 eyelid 7:25 swelling with or without redness erythema, the presence of ophthalmoplegia, 7:32 pain with 7:33 eye movement, decreased vision, relative afferent pupillary defect and propt 7:39 osis occur only 7:41 with orbital cellulitis. 7:43 CT and MRI scan of the orbit sinus is important for diagnosis. 7:49 In this CT image, you can see a case of orbital cellulitis of the right orbit 7:54 and you can 7:54 see inflammation of the extraocular muscles, the fat stranding and anterior 7:59 displacement 7:59 of the globe. 8:00 This person has proptosis. 8:03 There is also peri-orbital cellulitis as well on top of this. 8:08 Any worsening of the patient's symptoms or signs should lead to repeat imaging 8:12 using 8:13 CT scans to determine the necessity for surgical intervention. 8:23 Finally treatment of orbital cellulitis and peri-orbital cellulitis is really 8:27 using empirical 8:28 therapy with antibiotics. 8:32 All cellulitis, for example, vancomycin plus keftrioxone metronitazole or van 8:36 comycin and 8:38 tazosin, again each country may differ. 8:43 Modify your regime based on microbiology diagnosis. 8:48 With mild peri-orbital cellulitis, amoxicillin and clavulinate can be used 8:59 orally. 9:01 So in summary, in this video we talked about orbital cellulitis and peri-orb 9:06 ital cellulitis. 9:08 Orbital cellulitis is an ophthalmic emergency because it can cause vision loss 9:12 through several 9:13 mechanisms. 9:15 The most useful way to distinguish between the two is through clinical features 9:20 . 9:20 With orbital cellulitis, you have pain on eye movement, decreased vision, propt 9:27 osis amongst 9:28 pupillary changes, especially with light. 9:33 Thank you for watching.
