Endophthalmitis is inflammation of vitreous and inner coats of eyeball. Endophthalmitis can be classified according to the
- Mode of entry
- Type of etiological agent
According to mode of entry
In this type of Endophthalmitis Micro-organisms introduced directly from environment and it usually occurs following surgery i.e. post-operative Endophthalmitis or trauma i.e. post-traumatic or keratitis. It is mainly bacterial in origin but can be fungal also.
In this group of Endophthalmitis occurs due to blood borne spread of organisms as a metastatic infection without any structural defect of eye. Common predisposing factors of endogenous Endophthalmitis are immunocompromised status, septicemia or IV drug abuse and it is mainly fungal in origin.
According to type of organisms it can be
Post-operative endophthalmitis is the most common form and it comprises 70% of infective Endophthalmitis. Post operative Endophthalmitis (POE) is defined as a severe inflammation involving both the anterior and posterior segments of the eye secondary to an infectious agent. It may occur after any ocular surgical procedure. Large majority follow cataract surgery, most common surgical procedure (approx prevalence 0.082%- 0.1%) and Post- operative endophthalmitis is one of the most dreaded complications of cataract surgery and constitutes a true emergency.
Clinical features of Endophthalmitis are
- Red eye
- Decreased vision
- Hazy cornea
Three forms of clinical presentation can be distinguished
- Acute form– it occurs within post-operative 2-4 days and is usually fulminant
- Delayed form– it is moderately severe and occurs within post-operative 5-7 days,
- Chronic form– this forms occurs as early as 1 month post-operatively and is usually fungal in origin,
Diagnosis of Endophthalmitis
Clinical picture can be confirmed by culture of the organisms. The most important samples to culture are aspirates from the aqueous and vitreous cavity.Possibility of isolating an organism from vitreous 56-70% while from aqueous 36-40%. Polymerase chain reaction to identify the micro organism genomes is also an alternative for culture.
Management of Endophthalmitis: Endophthalmitis Vitrectomy Study (EVS), a multicenter study has provided guidelines for management of POE.
In established endophthalmitis, antibiotics when given orally or I.V. have poor penetration into the vitreous cavity. Hence, intravitreal injections are treatment of choice because intravitreal injections bypass the blood retinal barrier and rapidly achieve therapeutic levels at the sites of infection.
For gram positive organisms–Intravitreal Vancomycin 1 mg in (0.1 ml) is treatment of choice
For gram negative organisms –Intravitreal Ceftazidime 2.25 mg/0.1 ml is treatment of choice
So, Vancomycin combined with Ceftazidime appears to be best association in treatment of Postoperative Endophthalmitis.
For Fungal endophthalmitis intravitreal Amphoptericin B & Voriconazole is treatment of choice.
Multiple intravitreal injections may be needed for complete eradication of micro organisms.
Initial Vitrectomy is only beneficial for patients presenting with a very poor visual acuity. However, Vitrectomy is also being done to reduce the micro-organism load in case of refractory endophthalmitis.