Anterior Chamber Aspirate Research Articles

Intraocular gentamicin sulfate and postcataract anterior chamber aspirate cultures

We cultured anterior chamber aspirates of 28 patients who had uncomplicated cataract surgery. Fourteen patients had received 80 μg/ml of gentamicin in balanced salt solution through irrigation of the anterior chamber throughout cataract extraction, and 14 patients had received 8 μg/ml of gentamicin. Cultures of anterior chamber fluid obtained at the end of surgery from all 28 patients had no growth on two nonselective media. There was no clinical evidence of ocular toxicity. This study demonstrates that antibiotic in the intraocular irrigation fluid can reduce or eliminate the expected intraocular bacterial load after cataract surgery.

Bacterial contamination during extracapsular cataract extraction. Prospective study on 200 consecutive patients.

Postoperative endophthalmitis remains one of the most devastating complications of eye surgery. In recent years infections with so called 'nonpathogenic' organisms like Propionibacterium acnes or coagulase-negative staphylococci have gained in importance. 200 patients were included in this study, from whom preoperative smears of the conjunctiva and intraoperative aspirates of the anterior chamber (at the start and at the end of the operation) had been taken. All samples were investigated for aerobe and anaerobe microorganisms and fungi. 75% of the preoperative smears had been contaminated, with coagulase-negative staphylococci the most commonly isolated bacteria. But, in addition, 28% of the patients had culture-positive anterior chamber aspirates, also with coagulase-negative staphylococci as the most frequent organisms. In all cases inoculum sizes were extremely small (10-20 c.f.u./ml). Probably because of this small inoculum, but also due to the bacteriocidal qualities of the aqueous humor and the integrity of the posterior capsule sac, in no case had postoperative endophthalmitis developed. For the first time, our study tried to correlate the contamination of the anterior chamber aspirate to the used operation technique: first results show that the contamination of the aqueous humor is significantly lower (p < 0.03) if the cataract extraction is performed by phacoemulsification than if done without.

Anterior Chamber Aspirate Cultures After Uncomplicated Cataract Surgery

We cultured anterior chamber aspirates of 30 patients who had uncomplicated extracapsular cataract extraction or phacoemulsification. The aspirate was obtained at the time of wound closure. Of 30 patients, 13 (43%) had culture-positive anterior chamber aspirates. The total number of organisms recovered was 18, with three patients having multiple organisms identified. The most commonly isolated organisms were coagulase-negative Staphylococcus sp., occurring in eight of 18 isolates (44%). No eyes in our study developed endophthalmitis, even though almost one half had viable organisms growing from the anterior chamber aspirates. Inoculum sizes were extremely small (10 to 20 colony-forming units/ml). This study suggests that in humans, the anterior chamber is capable of clearing a low inoculum of bacteria after cataract surgery without the development of endophthalmitis.

Comparison of Specular Microscopy and Examination of Aspirate in Phacolytic Glaucoma

Although phacolytic glaucoma is well known and the clinical picture is well recognized, the nature of the polychromatic hyperrefringent granules is less well understood. A series of five cases was examined by specular microscopy, and the anterior chamber aspirate obtained at operation was subsequently examined by direct microscopy of the wet aspirate. Direct microscopy showed that the macrophages identified histologically in the aspirate corresponded to regular round cells about three times the size of an erythrocyte seen in the relief mode of specular microscopy. This finding aided in the interpretation of cellular deposits seen on specular microscopy. One hyperrefringent granule was seen on the posterior endothelium on specular microscopy, and results of subsequent examination of the aspirate showed this and the crystals in another patient to be morphologically identical with cholesterol crystals. The findings confirm that cholesterol crystals are present in the exudate in phacolytic glaucoma and are responsible for hyperrefringent granules.

Bacterial contamination of intraocular and extraocular fluids during extracapsular cataract extraction.

Fluid aspirated from the anterior chamber and fluid drained from the conjunctival sac during 101 extracapsular cataract operations was examined for bacterial contamination. Bacteria were grown by enrichment culture from the conjunctival sac of 90 eyes and from the anterior chamber aspirate of 29 eyes. Conjunctival fluid, stained with fluorescein, was demonstrated to flow into the anterior chamber during the aspiration stage of extracapsular cataract extraction and during intraocular lens implantation. It is suggested that this fluid from the conjunctival sac, contaminated with bacteria, routinely enters the anterior chamber during extracapsular cataract extraction and is the likely source of some cases of post-operative endophthalmitis.

Ghost Cell Glaucoma Following Trauma

Ghost cell glaucoma was described in 1975. The details of this glaucoma as it occurred following vitrectomy and following cataract extraction have been reported. This glaucoma occurred following trauma as well, and this report describes the clinical and pathologic characteristics. Fourteen patients, five with positive anterior chamber aspirate examinations, were studied. All had in common: (1) severe trauma to the eye, either blunt or penetrating, with hyphema and vitreous hemorrhage; (2) gradual clearing of the anterior chamber hemorrhage and conversion of fresh red blood cells to ghost cells in the vitreous cavity; (3) forward passage of ghost cells into the anterior chamber through a traumatic opening in the anterior hyaloid face; and (4) elevation of intraocular pressure caused by these cells approximately two weeks to three months following the trauma. The glaucoma required medical and often surgical therapy. The surgical procedure of choice was anterior chamber irrigation, which was often effective and is advised before proceeding to vitrectomy. The vitreous findings of an enucleated eye with ghost cell glaucoma are presented.

Management of Infectious Endophthalmitis

Diagnostic anterior chamber and vitreous aspiration confirmed an infectious etiology in 78 of 140 eyes (56%) with suspected endophthalmitis. In 27 eyes the vitreous aspirate was positive, while the anterior chamber aspirate was negative. Intraocular antibiotics were used in 88 eyes including 50 which underwent therapeutic vitrectomy. Vision of 20/20 to 20/400 was achieved in 57% of recently operated, culture-positive eyes treated with intraocular antibiotics, and in 59% of those treated with combined vitrectomy and intraocular antibiotics.

Endophthalmitis After Staphylococcal Sepsis-Reply

In Reply.— We very much appreciate the comments of Dr Joseph about our article and would like to clarify some of the points he has raised. First, we totally agree with Dr Joseph that ocular paracentesis is important in making the diagnosis of bacterial endophthalmitis. In our discussion, we pointed out the less well-known observation that a negative anterior chamber culture does not rule out a bacterial endophthalmitis. We also agree about the lack of specificity of a polymorphonuclear leukocyte response in anterior chamber aspirate; in fact, we did not even bother to include that finding in our discussion of the possible bacterial cause of the endophthalmitis. We disagree with Dr Joseph in his statement that there is no evidence that the impaired inflammatory and immune responses in uremia can lead to a more indolent course of an infectious process. The clinical course of hepatitis B infection is more indolent

Etiology and Diagnosis of Bacterial Postoperative Endophthalmitis

It is necessary to determine if postoperative endophthalmitis is of infectious or sterile etiology. Intraocular contents should be cultured and were positive in 50% of 58 eyes tested at our institute with suspected postoperative endophthalmitis. The vitreous aspirate is more sensitive than the anterior chamber aspirate in making a diagnosis. The use of a membrane filter to concentrate vitreous samples obtained at vitrectomy increases diagnostic yield. Fifty percent of culture-positive eyes yielded gram-positive organisms. Stained smears were consistent with the cultured organism in half of the cases.

Glaucoma Occurring after Closed Vitrectomy

Six of 20 eyes developed postoperative glaucoma within two to ten days after closed vitrectomy for vitreous hemorrhage. Intraocular pressure was greater than 40mm Hg in all six eyes, and three developed pressure greater than 60 mm Hg. Intraocular pressure in four eyes was controlled with medical antiglaucoma therapy and two eyes required anterior chamber irrigation. Six months postoperatively three of the eyes had normal pressures, one was hypotonous, and two developed increased intraocular pressure secondary to angle neovascularization. Three of the 14 eyes that did not develop glaucoma developed a cellular accumulation in the anterior chamber. The glaucoma was caused mainly by obstruction of the trabecular meshwork by degenerated red blood cells known as ghost cells. The cells may be identified by phase-contrast examination of anterior chamber aspirates. Glaucoma can be prevented through irrigation of the vitreous cavity at the time of vitrectomy ensuring that no cells and debris are left behind to migrate into the anterior chamber and obstruct the trabecular meshwork. This type of glaucoma is caused mainly by ghost cells, whereas hemolytic glaucoma is caused mainly by macrophages and red blood cell debris.

Unusual Presentation of Phacoanaphylaxis Following Phacoemulsification

A case of phacoanaphylaxis following phacoemulsification is presented. The unusual features of the disease included the markedly delayed onset and the clinical appearance of the hypopyon. Emphasis is placed on the cytologic examination of anterior chamber aspirate in such cases.

Ghost Cells as a Cause of Glaucoma

Clinical and investigative evidence indicated a glaucoma caused mainly by degenerated red blood cells, or ghost cells. These ghost cells, with altered shape, color, and pliability, accumulated in the vitreous cavity after hemorrhage. Following disruption of the anterior hyaloid face, they passed into the anterior chamber and caused severe glaucoma. In the anterior chamber, the tiny, khakicolored cells, circulating slowly, were frequently mistaken for white blood cells. They covered the trabecular meshwork or filled the inferior angle with a pathognomonic khaki-colored layer. They were identified by phase-contrast microscopic examination of anterior chamber aspirates. The decreased pliability of these degenerated cells seemed to account for their inability to pass easily through the human trabecular meshwork and, therefore, to cause severe glaucoma.

Adult Cytomegalovirus Inclusion Retino-Uveitis

A 27-year-old male renal transplant recipient acquired cytomegalovirus (CMV) infection of both eyes. This was characterized early by a distinctive necrotic retinitis with discrete advancing edges. A large exudative retinal detachment and hypopyon developed in one eye, and cultures from the anterior chamber aspirate grew CMV. Cytomegalovirus was also isolated from the urine and throat; after serial negative base-line titers, CMV antibody titer became positive. At autopsy CMV was isolated from lung, esophagus, and kidney tissue. Light and electron microscopic studies demonstrated extensive necrosis and disruption of the sensory retina and retinal pigment epithelium with exudative retinal detachments. The diseased retinal cells contained a multiplicity of viral particles in various stages of maturity. Cytomegalic inclusion-bearing cells were demonstrated in the choroid of the more severely affected eye.