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]
It is thought that bleb related infections begin secondary to bleb leakage. Bleb leakage allows organism from the tear film to colonise the bleb and invade the anterior chamber or the vitreous even in a late post-operative period.
Antifibrotic agents, such as mitomycin C(MMC) and 5-fluorouracil (5-FU), are used to prevent fibrosis and scarring of the scleral flap and bleb. It is thought that the use of antfibrotic agents may result in bleb leakage and subsequent bleb-related endophthalmitis (BRE). Nucleic acid metabolic inhibition by the antifibrotic agents may be caused bleb leakage and subsequent intraocualr infection through following mechanism:[3]
- Reduce mucin production (secondry to loss of gablet cell)
- General conjunctival thinning
- Reduced cellularity
- Avascular bleb
Causes
Common causes of bleb-related endophthalmitis include:[1]
- 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 13,000 per 100,000 individuals.[4][5] The incidence of bleb-related endophthalmitis is approximately 3,000 per 100,000 individuals with the use of antiproliferative agent. The incidence of bleb-related endophthalmitis is approximately 9,000 per 100,000 individuals with inferior placement of bleb.
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][3][6][7]
- Late onset 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)) may cause bleb leakage by following mechanism:
- Reduce mucin production (secondry to loss of gablet cell)
- General conjunctival thinning
- Reduced cellularity
- Avascular bleb
- Epithelial irregularities, basement membrane breaks, and hypocellularity
- Inappropriate use of of The antifibrotic agents (such as 5-fluorouracil (5-FU) and Mitomycn-C (MMC)) may cause bleb leakage by following mechanism:
- 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
Natural History, Complications, and Prognosis
Natural History
Complications
Prognosis
Bleb-related endophthalmitis is associated with a poor prognosis. 5/200 visual acuity achieves on half of the patients who developed bleb-related endophthalmitis.
Diagnosis
Diagnostic Criteria
History and Symptoms
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
Medical Therapy
Surgery
Prevention
Primary Prevention
- Assessment of bleb leakage following tabeculectomy surgery in every vist
- 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 1.5 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 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.
- ↑ Sharan S, Trope GE, Chipman M, Buys YM (2009). "Late-onset bleb infections: prevalence and risk factors". Can J Ophthalmol. 44 (3): 279–83. doi:10.3129/i09-050. PMID 19491982.
- ↑ Alwitry A, King AJ (2012). "Surveillance of late-onset bleb leak, blebitis and bleb-related endophthalmitis--a UK incidence study". Graefes Arch Clin Exp Ophthalmol. 250 (8): 1231–6. doi:10.1007/s00417-011-1920-5. PMID 22249317.
- ↑ 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.