Intraocular Contamination Research Articles

Novel options in diagnosis and treatment of endophthalmitis

AbstractEndophthalmitis remains the most vision‐threatening condition that in most severe cases can result in a loss of an eye and systemic spreading of the infection. It is defined as an acute inflammation of the inner tissues of the eyeball and is usually caused by intraocular contamination and colonization of infectious agents with exudation within intraocular space. The development of endophthalmitis as well as its clinical presentation and functional and anatomical outcomes is predefined by its type, kind of infection and therapy applied. There is a risk of progression of endophthalmitis to panophthalmitis, which could end up with evisceration or enucleation. The involvement of the general physician and other medical specialists into the treatment of the patients with endophthalmitis shall be always considered and should not be underestimated. As one of the most severe emergencies in ophthalmology, this condition requires urgent therapeutical or/and surgical intervention. Numerous studies compare the efficacy of the first line treatment for different types of endophthalmitis. Since decades the management of endophthalmitis is based on prompt recognition of infectious agents, immediate intraocular antimicrobial therapy and removal of the purulent exudate form the eye. Novel diagnostic options for endophthalmitis shall be considered in order to increase the precision of to treat patients with endophthalmitis. Improvement of the surgical techniques with the development of the new less traumatic instruments and he novel antimicrobial drugs can stablish a new standards of endophthalmitis care.

Ophthalmic viscosurgical device backflow into cartridge during intraocular lens insertion using injectors

BackgroundThe purpose of this study was to assess the risk of intraocular contamination caused by intraocular lens (IOL) insertion with injectors by observing the dynamics of an ophthalmic viscosurgical device (OVD).MethodsEach type of injector was equipped with a colored OVD and IOL, and a 2 mm length from the tip of the cartridge was replaced with a colored OVD. The various combinations of IOLs and injectors used were: a three-piece shaped IOL, VA60BBR + TypeE1 (HOYA incision size 2.5 mm; group A, n=5); a single-piece IOL, 251+ iSert micro, preloaded (HOYA, incision size 2.2 mm; group G, n=5); and a single-piece IOL, SN6CWS preloaded (Alcon, incision size 2.7 mm; group C, n=5).ResultsIn group A, the intraocular OVD instantly flowed backward into the injector, whereas the colored OVD was pushed backward deep inside the cartridge without flowing into the eye. In group B, the backflow of the intraocular OVD into the injector was limited, resulting in the influx of a large amount of the colored OVD into the eye along with the IOL. In group C, as in group A, a large amount of the intraocular OVD flowed backward into the injector. Consequently, a small amount of the colored OVD flowed into the eye.ConclusionThe tip of the injector and OVD could be contaminated because the surgical field cannot be completely sterile, even after preoperative disinfection. Our experiments revealed that OVD backflow into the injector cavity occurs during IOL insertion, and this phenomenon may have minimized intraocular contamination. However, small-diameter cartridges along with plate-type haptics allow insufficient OVD backflow, resulting in intraocular influx of the contaminated OVD. Surgeons have to be notified that intraoperative bacterial contamination can occur even after IOL insertion using injectors.

Response to Nestel

Sir, We thank Dr Nestel1 for his interest in our study.2 We found some associations between the pathogenic conjunctival bacteria and the systemic co-morbidities of patients undergoing cataract surgery, which was the main purpose of the study. Among these associations, we found that enterococci prevalence is associated with age and diabetes. Owing to the current wide use of intracameral cefuroxime for the cataract surgery prophylaxis,3, 4 we introduced the example of the postoperative endophthalmitis (PE) caused by enterococci for illustrating the implications of our findings in the management of patients carrying conjunctival bacteria resistant to a particular prophylaxis, such as the enterococci to cefuroxime, as Dr Nestel pointed. The systemic co-morbidities associations with other bacteria (for instance multi-resistant Staphylococcus) could also help in choosing a prophylaxis. The answers to other comments are as follows: In the study design, polymyxin B plus trimethoprim eye drops is an empirical prophylaxis for all patients, except those having conjunctival pathogen bacteria resistant to these antibiotics, such as enterococci. We try not to increase the resistance to first-line antibiotic treatments. The occurrence of four PE cases in the first year of the study period2 was before using intracameral cefuroxime. This fact could point to streptococci as the most likely cause, as there was no case of Streptococci-PE in the ESCRS groups treated with cefuroxime,5 and no others prophylactic measures had changed in our study. The oral antibiotic for patients with conjunctival enterococci was chosen in accordance with their susceptibility tests;6 quinolones being the first choice, if possible. Finally, the ‘potential' risk of intraocular contamination by enterococci, in patients over 85 years, was calculated with respect to the conjunctival enterococci prevalence of patients younger than 86 years (Supplementary Table 3).2 This information is extended in Table 1. Table 1 Increasing potential risk of intraoperative contamination by enterococci according to age in patients operated on for cataract

HEALING OF CONJUNCTIVAL WOUNDS AFTER 23-GAUGE SUTURELESS VITRECTOMY

To evaluate the healing course of conjunctival wounds in eyes undergoing 23-gauge sutureless vitrectomy and to determine when the potential for ocular surface fluid contamination is no longer a serious concern. Prospective observational case series. Thirty-four eyes from 34 patients that underwent transconjunctival 23-gauge sutureless vitrectomies were included. A total of 102 conjunctival wounds overlaying the sutureless sclerotomies from 34 eyes were evaluated prospectively by slit-lamp biomicroscopic examination using cobalt blue light with fluorescein dye staining. The configuration and size of the conjunctival wounds were measured with fluorescein dye staining postoperatively on Days 1, 4, 8, and 15. Seventy-five conjunctival wounds (73.5%) had not healed completely 4 days after the operation. Eight days after surgery, the proportion of eyes with fluorescein staining at the conjunctival wound decreased to 13.7%. Fifteen days after surgery, there was no fluorescein staining at the conjunctival wound in any case. Combined cataract extraction was a factor that delayed the healing of the conjunctival wound (P = 0.036). The results suggest that, regarding conjunctival integrity, patients should be safe from intraocular contamination 15 days after 23-gauge sutureless vitrectomy. Concomitant cataract extraction might lengthen the conjunctival wound healing process in these eyes.

Early post-phacoemulsification hypotony as a risk factor for intraocular contamination: In vivo model

To observe cataract wound dynamics and determine the risk for intraocular contamination under induced conditions of early postoperative hypotony after anterior chamber decompression for high intraocular pressure (IOP) spikes after uneventful phacoemulsification surgery. Department of Ophthalmology, Queen's Hospital, Burton-on-Trent, United Kingdom. In a prospective case series, 30 patients were treated with anterior chamber decompression for elevated IOP (>35 mm Hg) 1 to 2 hours after uneventful phacoemulsification through clear corneal temporal incisions. A drop of 2% fluorescein was instilled in the conjunctival sac before aqueous release to study the ocular fluid movements during and after the decompression procedure. The patterns of fluorescein movement were observed and photographed under cobalt blue light. Fluorescein staining of the entire corneal tunnel was observed in all 30 eyes after decompression. An immediate fluorescein flare was observed in the anterior chamber after aqueous release in 24 eyes (80%) (P<.001). Observations over several seconds after decompression found a frank influx of fluorescein-stained fluid into the anterior chamber in 12 eyes (40%) (P<.001), giving rise to an "inverse Seidel's test." An intermittent ingress of fluorescein-stained fluid continued for several minutes after the procedure in 6 eyes (20%) (P<.05). An incompetence of clear corneal cataract wound with intraocular contamination was observed during the period of induced hypotony after anterior chamber decompression in the early post-phacoemulsification period.

Inflow of Ocular Surface Fluid Into the Anterior Chamber After Phacoemulsification Through Sutureless Corneal Cataract Wounds

To report inflow of extraocular fluid after phacoemulsification with use of sutureless corneal incisions. Interventional case series. setting: Wilmer Eye Institute, Johns Hopkins Hospital, Baltimore, Maryland. patients: Eight patients (three women), aged 58 to 91 years, showing minimal bleeding from the limbal capillary bed during phacoemulsification. intervention: Surgery was performed through a 2.8-mm limbal incision. External pressure simulating patient manipulation was applied before and after wound hydrosealing with an irrigation cannula. main outcome measures: Inflow of blood-tinged tear fluid into the anterior chamber through the wound was monitored by using digital video. Inflow of extraocular fluid was observed in all eyes when the cannula was released, even after wound hydrosealing. Two patients showed spontaneous fluid inflow. Tested sutureless corneal incisions allow inflow of extraocular fluid into the anterior chamber after phacoemulsification. This may permit intraocular contamination leading to endophthalmitis.

The role of intraocular lenses in anterior chamber contamination during cataract surgery.

Bacterial endophthalmitis is a rare vision-threatening disease, usually caused by microorganisms that are natural inhabitants of the eye lids and conjunctiva. This study was conducted to investigate the role of intraocular lenses (IOLs) in introducing bacterial contamination into the eye during cataract surgery and the efficacy of povidone-iodine solution in prevention this ocular inoculum. Fifty patients underwent routine cataract surgery and intraocular lens implantation. One group of the patients was pretreated with external disinfection using povidone-iodine 4% before surgery, while the other group was only pretreated with saline irrigation. Before IOL implantation, a test IOL was placed on the conjunctiva and taken for microbiological studies. Anterior chamber tap was done at the beginning and at the end of each operation. Positive bacterial growth was followed by bacterial identification and sensitivity tests to various antibiotics. Bacterial growth was obtained in 14 of the 50 eyes (28%); in 5 eyes the organism was cultured from tapped aqueous and in 9 eyes from the test IOLs. Prophylactic use of povidone-iodine 4% solution effectively reduced the contamination rate from 34.7% to 16.7%. Coagulase-negative staphylococci were the most common organisms isolated (72%). Most organisms were sensitive to vancomycin (86%) and to fucidic acid (71%). There were no cases of clinical endophthalmitis. IOLs are apparently potential vehicles for introduction of intraocular bacterial contamination. Instillation of povidone-iodine 4% into the cul-de-sac reduces the risk of bacterial inoculum. Vancomycin is the most effective single agent against intraocular contamination. In order to reduce potential intraocular contamination it is advisable to avoid contact between the IOL and ocular tissues.

Peroperative microbial contamination of anterior chamber aspirates during extracapsular cataract extraction and phacoemulsification

BACKGROUNDThe normal conjunctival flora is one of the main sources of intraocular contamination during cataract surgery. The theory that the positive anterior chamber (AC) pressure during phacoemulsification (phaco), and the...

Vancomycin prophylaxis and intraocular contamination during cataract surgery

Purpose: To investigate the effect of vancomycin added to the intraocular irrigation solution to prevent anterior chamber contamination during phacoemulsification.Setting: Centre Hospitalier, Villeneuve-Saint-Georges, France.Methods: A group of 372 patients having cataract extraction by phacoemulsification was divided into two consecutive, nonrandomized groups. The first group (n = 190) was a control; there was no antibiotic in the irrigation solution. The second group (n = 182) received vancomycin in the irrigation solution. Intraocular fluid was aspirated at the end of surgery and injected into a blood culture bottle to evaluate bacterial contamination of the anterior chamber.Results: There was no between-group difference in bacterial intraocular contamination. Eight samples in the first group were contaminated and nine in the second group. All contaminants were gram-positive vancomycin-sensitive organisms.Conclusions: Adding vancomycin to the intraocular irrigation solution during cataract surgery had no effect on the occurrence of intraocular contamination as evaluated by anterior chamber taps.

Intraocular bacterial contamination during cataract surgery in dogs

Summary Prevalence of intraoperative contamination of the eyelids, conjunctival sac, and aqueous humor of 50 canine eyes that underwent elective cataract surgery was determined, and the short-term outcomes for contaminated and noncontaminated eyes were compared by scoring media clarity, pupil size and shape, and behavioral evidence of vision during the initial 30-day postoperative period. Results of bacteriologic culture of anterior chamber samples were positive for 12 of the 50 (24%) eyes, but anterior chamber contamination was unrelated to results of bacteriologic culture of eyelids or conjunctival sac swab samples. Eyes undergoing phacoemulsification were less likely to be contaminated than were eyes undergoing intra- or extracapsular extraction. Eyes undergoing intra- or extracapsular extraction and eyes with anterior chamber contamination had a greater likelihood of developing glaucoma postoperatively. We did not detect an association between intraocular contamination and the surgeon performing the operation, the need for postoperative administration of tissue plasminogen activator, or the presence or absence of diabetes mellitus. Also, we did not detect any differences in outcome between eyes with and without intraocular contamination. Despite intraoperative bacterial contamination of the anterior chamber, bacterial endophthalmitis did not develop in any of the eyes.

Intraocular contamination during extracapsular cataract extraction with intraocular lens implantation

Ocular bacterial contamination has been studied in 45 eyes that underwent cataract surgery. The following samples were taken: (1) eyelid margin swab; (2) conjunctival swab; (3) aqueous humor after initial anterior chamber penetration; (4) anterior capsule fragment after capsulorrhexis or capsulotomy; (5) cortical lens material; (6) anterior chamber fluid after lens implantation. The percentages of contaminated samples were 15.5, 13.3, 0.0, 11.1, 13.3 and 6.6, respectively. There was a significant difference between the incidence of positive cultures in the aqueous humor at the time of incision and in subsequent intraocular samples. Positive cultures were found in 13 out of 45 eyes, only gram-positive organisms were recovered and coagulase-negative staphylococci were the most common (78.5% of the isolates). These results confirm previous reports on intraocular contamination during cataract surgery.