Bleb-related endophthalmitis
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Sara Mehrsefat, M.D. [2]
Overview
Bleb-related endophthalmitis (BRE) is the second most frequent cause of postoperative endophthalmitis after acute and chronic post-cataract surgery endophthalmitis.[1][2]
Historical Perspective
Classification
Depending on the timing of presentation and duration, bleb-related endophthalmitis (BRE) can be classified into:
- Early onset (Less than 6weeks since surgery)
- Late onset (more than 6wkeeks since surgery)
Pathophysiology
Trabeculectomy is performed to achieve very low intraocular pressure (IOP) in glaucoma eye that has failed medical management. Filtering bleb is a surgically created defect in the sclera which allows excess aqueous humor to leak out of the anterior chamber and be absorbed into the systemic circulation. There is a serious concern for bleb-related endophthalmitis (BRE) even after successful trabeculectomy.[1][2]
The exact pathogenesis of bleb-related endopthalmitis is not fully understood. It is thought that bleb-related endophthalmitis is the result of bleb leakage, which allows bacteria from the tear film and the periocular structures access into the anterior chamber or the vitreous.
It is thought that early leakage may be caused by either wound dehiscence or incomplete conjunctival closure. It is also thought that the use of antfibrotic agents, such as mitomycin C(MMC) and 5-fluorouracil (5-FU), may result in bleb leakage and subsequent late onset bleb-related endophthalmitis (BRE).
These antifibrotic agents are used to prevent fibrosis and scarring of the scleral flap and bleb and may result in bleb leakage by following mechanism:
- Early onset BRE
- Late onset BRE
- Streptococcus species (31%)
- Staphylococcus species (7%-22%)
- Gram negatives bacteria such as (Haemophilus influenzae 23%, Enterococcus 7%, Pseudomonas 7%)
- Post-operative endophthalmitis
- Blebitis
Epidemiology and Demographics
Incidence
The incidence of bleb-related endophthalmitis is approximately range from 170 to 1,300 per 100,000 individuals..[3][4] The incidence of bleb-related endophthalmitis is approximately 3,000 per 100,000 individuals with the use of antiproliferative agent.[3][5]
The incidence of bleb-related endophthalmitis is approximately 9,000 per 100,000 individuals with inferior placement of bleb.[3][6]
Age
The incidence of bleb-related endophthalmitis decreases with age. Many studies have shown a higher prevalence of blebitis in younger, male, and black patients.
Gender
Males are more commonly affected with bleb-related endophthalmitis than females.
Race
Black patients are more commonly affected with bleb-related endophthalmitis.
Developed countries
In the United States, the incidence of bleb-related endophthalmitis is approximately range from 450 to 1,300 per 100,000 individuals with trabeculectomy after up to 5 years follow up.[2]
Risk Factors
Common risk factors in the development of bleb-related endophthalmitis include:[1][2][7][8][9]
- Bleb leakage (increase the risk of bleb infection 26 fold)
- Inappropriate use of of The antifibrotic agents (such as 5-fluorouracil (5-FU) and Mitomycn-C (MMC))
- Age under 60 years
- Inferior and nasal placement of bleb
- Conjunctivitis,
- Upper respiratory infection,
- Blepharitis
- Diabetes
- Trabeculectomy alone compared to combined procedure
- Chronic antibiotic use
- Trabeculectomy without concurrent cataract extraction,
- Early complications (such as early wound leak, choroidal hemorrhage, and a flat chamber)
- Juvenile glaucoma
- Nasolacrimal duct obstruction,
- Contact lens wear
- Bleb revision surgery
- Epinephrine drops
Screening
Screening for bleb leakage by ophthalmologist following each visit is recommended among patients with trabeculactomy surgery.
Natural History, Complications, and Prognosis
Natural History
Bacterial endophthalmitis is a medical emergency. If left untreated, It may lead to panophthalmitis, corneal infiltration, corneal perforation, and ultimately permanent vision loss.
Complications
Complications to rheumatic fever include:
- Panophthalmitis
- Corneal perforation
- Vision loss
Prognosis
Bleb-related endophthalmitis is associated with a poor prognosis. Even with appropriate treatment, half of the patients with bleb-related endophthalmitis achieve 5/200 visual acuity, and only 10% achieve 20/40 or better.
Diagnosis
Diagnostic Criteria
History and Symptoms
Specific areas of focus when obtaining a history from the patient with bleb-related endophthalmitis include:
- History of trabeculectomy
- History of blebitis
- Use of adjunctive anti-metabolites , such as mitomycin C(MMC) and 5-fluorouracil (5-FU)
Symptoms
Symptoms of bleb-related endophthalmitis may include the following:[1][2]
- Ocular pain and discomfort
- Redness
- Blurred vision
- eye Discharge
- Loss of vision
- Eyebrow ache
- Headache
- External ocular inflammation
Physical Examination
Eye examination
- Whitened bleb surrounded by intense conjunctival injection
- A mucopurulent infiltrate,
- Precipitates similar to keratic precipitates
- Hypopyon within the bleb (often avascular with thin walls)
- Anterior chamber reaction and/or a hypopyon, depending on the duration of the blebitis. Frequently, there is a
- Bleb leak and consequent hypotony
Laboratory Findings
Imaging Findings
X Ray
CT
MRI
Ultrasound
Other Imaging Findings
Other Diagnostic Studies
Treatment
- The patient needs urgent examination by an expert ophthalmologist and/or vitreo-retina specialist who will usually decide for urgent intervention to provide intravitreal injection of potent antibiotics and also prepare for an urgent pars plana vitrectomy as needed. Enucleation may be required to remove a blind and painful eye.
- Bacterial and fungal cultures from vitreous samples are necessary in the management of endophthalmitis
- Immediate vitrectomy is often necessary
Antimicrobial Regimens
- Infectious endophthalmitis[10]
- 1. Causative pathogens
- 2.Empiric antimicrobial therapy
- Preferred regimen: Vancomycin 1 mg per 0.1 mL normal saline intravitreal injection, single dose AND Vancomycin 1 g IV bid for 2 weeks AND Ceftazidime 2.25 mg per 0.1 mL normal saline intravitreal injection, single dose AND Ceftazidime 1 g IV bid for 2 weeks AND Clindamycin 600-1200 mg IV bid to qid for 2 weeks
- Note (1): Re-injection should be considered if the infection does not improve beyond 48 hours of the first injection. Re-injection significantly increases the risk of retinal toxicity.
- Note (2): In addition to intravitreal and systemic antibiotic therapy, vitrectomy is usually necessary
- 3. Pathogen-directed antimicrobial therapy
- 3.1 Bacillus spp.
- Preferred regimen: Vancomycin 1 mg per 0.1 mL normal saline intravitreal injection, single dose AND Vancomycin 1 g IV bid for 2 weeks AND Clindamycin 600-1200 mg IV bid to qid for 2 weeks
- Note: In addition to antimicrobial therapy, vitrectomy is usually necessary
- 3.2 Non-Bacillus gram-positive bacteria
- Preferred regimen: Vancomycin 1 mg per 0.1 mL normal saline intravitreal injection, single dose AND Vancomycin 1 g IV bid for 2 weeks
- Note: In addition to antimicrobial therapy, vitrectomy is usually necessary
- 3.3 Gram-negative bacteria
- Preferred regimen: Ceftazidime 2.25 mg per 0.1 mL normal saline intravitreal injection, single dose AND Ceftazidime 1 g IV bid for 2 weeks
- Note: In addition to antimicrobial therapy, vitrectomy is usually necessary
- 3.4 Candida spp.
- Preferred regimen: (Fluconazole 400-800 mg IV/PO qd for 6-12 weeks OR Voriconazole 400 mg IV/PO bid for 2 doses followed by 200-300 mg IV/PO bid for 6-12 weeks OR Amphotericin B 0.7-1.0 mg/kg IV qd for 6-12 weeks) AND Amphotericin B 5-10 microgram in 0.1 mL in normal saline intravitreal injection, single dose
- Note (1): In addition to antimicrobial therapy, vitrectomy is usually necessary
- 3.5 Aspergillus spp.
- Preferred regimen: Amphotericin B 5-10 microgram in 0.1 mL normal saline intravitreal injection, single dose AND Dexamethasone 400 microgram intravitreal injection, single dose
- Note (1): In addition to antimicrobial therapy, vitrectomy is usually necessary
- Note (2): Repeat antimicrobial regimen in 2 days post-vitrectomy
Surgery
Prevention
Primary Prevention
- Assessment of bleb leakage following tabeculectomy surgery in every visit
- Aggressive treatment of blebitis
- Bleb revision with conjunctival advancement to manage avascular leaking blebs (100% success rate)
- Amiotic membrane grafting as a possible alternative to conjunctival advancement (45% success rate)
Secondary prevention
- Bleb revision with conjunctival advancement to manage avascular leaking blebs (100% success rate)
- Amiotic membrane grafting as a possible alternative to conjunctival advancement (45% success rate)
References
- ↑ 1.0 1.1 1.2 1.3 1.4 Ohtomo K, Mayama C, Ueta T, Nagahara M (2015). "Outcomes of Late-Onset Bleb-Related Endophthalmitis Treated with Pars Plana Vitrectomy". J Ophthalmol. 2015: 923857. doi:10.1155/2015/923857. PMC 4606135. PMID 26495137.
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 Vaziri K, Kishor K, Schwartz SG, Maharaj AS, Moshfeghi DM, Moshfeghi AA; et al. (2015). "Incidence of bleb-associated endophthalmitis in the United States". Clin Ophthalmol. 9: 317–22. doi:10.2147/OPTH.S75286. PMC 4334336. PMID 25709395.
- ↑ 3.0 3.1 3.2 Ba'arah BT, Smiddy WE (2009). "Bleb-related Endophthalmitis: Clinical Presentation, Isolates, Treatment and Visual Outcome of Culture-proven Cases". Middle East Afr J Ophthalmol. 16 (1): 20–4. doi:10.4103/0974-9233.48862. PMC 2813581. PMID 20142955.
- ↑ Collignon-Brach J (1996). "[Surgery for glaucoma and endophthalmitis]". Bull Soc Belge Ophtalmol. 260: 73–7. PMID 9026310.
- ↑ Wolner B, Liebmann JM, Sassani JW, Ritch R, Speaker M, Marmor M (1991). "Late bleb-related endophthalmitis after trabeculectomy with adjunctive 5-fluorouracil". Ophthalmology. 98 (7): 1053–60. PMID 1891213.
- ↑ Higginbotham EJ, Stevens RK, Musch DC, Karp KO, Lichter PR, Bergstrom TJ; et al. (1996). "Bleb-related endophthalmitis after trabeculectomy with mitomycin C." Ophthalmology. 103 (4): 650–6. PMID 8618766.
- ↑ Matsuo H, Tomidokoro A, Suzuki Y, Shirato S, Araie M (2002). "Late-onset transconjunctival oozing and point leak of aqueous humor from filtering bleb after trabeculectomy". Am J Ophthalmol. 133 (4): 456–62. PMID 11931778.
- ↑ Yamamoto T, Sawada A, Mayama C, Araie M, Ohkubo S, Sugiyama K; et al. (2014). "The 5-year incidence of bleb-related infection and its risk factors after filtering surgeries with adjunctive mitomycin C: collaborative bleb-related infection incidence and treatment study 2". Ophthalmology. 121 (5): 1001–6. doi:10.1016/j.ophtha.2013.11.025. PMID 24424248.
- ↑ Soltau JB, Rothman RF, Budenz DL, Greenfield DS, Feuer W, Liebmann JM; et al. (2000). "Risk factors for glaucoma filtering bleb infections". Arch Ophthalmol. 118 (3): 338–42. PMID 10721955.
- ↑ Durand ML (2013). "Endophthalmitis". Clin Microbiol Infect. 19 (3): 227–34. doi:10.1111/1469-0691.12118. PMC 3638360. PMID 23438028.