Aqueous humor contamination during phacoemulsification in a university teaching hospital

Safety of intracameral injection of levofloxacin 0.5% eye drops single dose 0.6 ml preservative free on rabbit eye

Background

This was an experimental, parallel, and randomized study to evaluate the safety of single intracameral injection of 0.6 ml 0.5% preservative-free levofloxacin eye drops on rabbit eye.

Methods

In total, 24 eyes of 12 New Zealand white rabbits were divided into three groups. The first group (LFX) was treated with 0.1 ml intracameral injection of levofloxacin 0.5% eye drops of 0.6 ml preservative-free (n = 6), the second group (CRAV) was treated with 0.1 ml intracameral injection of levofloxacin 0.5% eye drops 5 ml commercially available eye drops preservative-free (n = 6), and the third group (BSS) were treated with 0.1 ml intracameral injection of balanced salt solution (n = 12). All groups received a single dose. The clinical evaluation was performed on the 1 st, 3 rd, 5 th, and 7 th day after injection. Each eye was enucleated on the 7 th day and underwent a histopathology examination.

Results

The clinical scores among the three groups did not show any significant difference on days 1 st, 2 nd, 3 rd, and 7 th (p>0.05). The only ones noted in clinical scores were mild corneal opacity, mild cells, and flares in the anterior chamber. The histopathology score demonstrated no statistically significant difference between the three groups (p>0.05). Vacuolization of corneal endothelial cells was noted in all groups but was not statistically significant.

Conclusions

A single intracameral injection of 0.6 ml 0.5% preservative-free levofloxacin eye drops was safe for rabbit eye, according to clinical and histopathology scores, similar to levofloxacin 0.5% eye drops in 5 ml bottle preservative free.

Use of Cryopreserved Amniotic Membrane During Pterygium Excision: Health Economic Analysis

Purpose

To determine the health economic opportunity cost or gain associated with performing pterygium excision surgery using the TissueTuck technique with cryopreserved amniotic membrane (AM) instead of conjunctival autograft (CAU).

Methods

We performed a literature review to determine the average surgical duration of pterygium surgery using CAU with fibrin glue or sutures to calculate the average time saved with the TissueTuck technique. Such time savings was then used to determine the opportunity revenue gain per national average Medicare reimbursement if adjusted to the average surgical duration of cataract surgery.

Results

The time savings achieved using the TissueTuck technique over CAU with fibrin glue is 8.9 min per procedure, which can be applied to additional MSICS or phacoemulsification procedures to generate an opportunity revenue gain of $1167 or $762 per 2022 National Average Medicare reimbursement, respectively. After subtracting the current list cost of AmnioGraft (ie, $645), the opportunity gain is $522 or $117 if the time saving is applied to the above procedures, respectively. Alternatively, the time savings achieved by using the TissueTuck technique over CAU with sutures is 23.4 min per procedure, which can be applied to additional MSICS or phacoemulsification procedures to generate an opportunity revenue gain of $3068 and $2004 per TissueTuck procedure or $2423 or $1359 when accounting for the list cost of AmnioGraft, respectively.

Conclusion

The TissueTuck surgical technique using cryopreserved AM for pterygium takes less time, has lower recurrence rates, and provides an opportunity gain compared to pterygium excision with CAU.

Prospective evaluation of the prevalence of conjunctival and intraocular bacteria in dogs undergoing phacoemulsification following a standardized aseptic preparation with 0.5% povidone iodine

PURPOSE

To evaluate bacterial contamination of conjunctiva and aqueous humor in dogs undergoing phacoemulsification following asepsis with 0.5% povidone iodine and determine the influence of intravenous antibiotics on outcome of contamination.

METHODS

Client-owned dogs were prospectively enrolled and randomly assigned to a control group, receiving 22 mg/kg intravenous cefazolin at induction prior to sampling, or experimental group receiving no antibiotic prior to sampling, masked to the surgeon. Dogs receiving antimicrobials in the pre-operative period were excluded. Asepsis was performed on all operated eyes using 0.5% iodine with minimum 3 min contact time at induction of anesthesia and repeated before surgery. A conjunctival swab and aqueous humor sample were collected prior to incision and following incision closure, respectively. Samples were submitted for aerobic and anaerobic bacterial culture and susceptibility.

RESULTS

Seventy-one eyes of 42 dogs were included. Median age was 9 years. Thirty-nine and 32/71 eyes received intravenous cefazolin and no antibiotic, respectively. Median procedure time was 40 min per eye. Conjunctival cultures were positive in 6 eyes (8.5%): Serratia marcescens (5 eyes) and Cutibacterium acnes (1 eye). Aqueous humor cultures were positive in 5 eyes (7.0%): S. marcescens (2 eyes), Pseudomonas aeruginosa (2 eyes), Staphylococcus pseudointermedius (1 eye). Prevalence of positive culture did not differ between groups (p = .74), order of eyes for bilateral procedures (p = .74) and diabetic status (p = 1).

CONCLUSIONS

Bacterial contamination of the conjunctiva and aqueous humor was present in 8.5% and 7.0% of dogs undergoing phacoemulsification after asepsis. Lack of IV cefazolin was not significantly associated with positive culture.

Long-Term Effect of Early Phacoemulsification in Primary Angle Closure Glaucoma Patients with Cataract: A 10-Year Follow-Up Study

Purpose

To assess the 10-year effects of early phacoemulsification with intraocular lens (IOL) implantation in primary angle closure glaucoma (PACG) patients with cataract.

Patients and Methods

This prospective cohort study included 102 eyes of 102 patients with PACG. All patients had coexisting cataracts compromising vision. Patients underwent phacoemulsification and foldable IOL implantation. The main outcome measures were anterior chamber depth (ACD), angle width, value of intraocular pressure (IOP), and number of medications needed postoperatively and during follow-up.

Results

Half (53%) of the patients were female, with ages ranging from 55 to 73 with a mean of 59.82±5.19 years. Mean IOP decreased significantly from 22.15±2.08 mmHg at baseline to 14.08±2.13 mmHg postoperatively (p˂ 0.05). The ACD increased from 2.2±0.21 preoperatively to 3.73±0.25 postoperatively (p˂0.001). Nasal angle width increased postoperatively to 40.05±2.09 compared to the preoperative value of 16.02±2.08 (p˂0.001). Temporal angle width increased from 13.05±2.07 to 41.9600±1.94 (p˂0.001). Anti-glaucoma treatment significantly decreased postoperatively (p˂0.001). A significant positive correlation was detected between ACD and angle width, while a negative correlation was detected between IOP and both ACD and angle width (p˂0.001). There was also a significant negative correlation between postoperative angle width and IOP (p˂0.001). Preoperative lens thickness was positively correlated with preoperative IOP and number of medications, while it was negatively correlated with preoperative AC depth and angle width. Preoperative lens thickness positively correlated with postoperative IOP and medications. Complete and qualified success was achieved in 69.65% and 30.4% of cases, respectively, while 2.9% failed to be controlled. Visual acuity significantly improved from 0.17±0.1 to 0.9±0.08 (p˂0.001). All parameters showed high stability throughout the follow-up period.

Conclusion

Phacoemulsification with IOL implantation is a safe and effective early modality for long-term control of IOP in PACG patients with coexisting cataract. The effects can persist for at least 10 years.

Molecular characterization and potential sources of aqueous humor bacterial contamination during phacoemulsification with intraocular lens implantation in dogs

Bacterial contamination of the anterior chamber during cataract surgery is one of the main responsible for endophthalmitis postoperative. Phacoemulsification is a less invasive technique for cataract treatment, although it does not exclude the possibility of contamination. In this study, bacterial contaminants of aqueous humor collected pre- and post-phacoemulsification with intraocular lens implantation (IOL) of twenty dogs were identified. As the conjunctival microbiota constitute a significant source of anterior chamber contamination, bacterial isolates from aqueous humor were genetically compared with those present in the conjunctival surface of the patients. Three dogs presented bacterial growth in both aqueous humor and conjunctival surface samples. Bacterial isolates from these samples were grouped according to their genetic profiles by repetitive-element PCR (rep-PCR) and their representatives were identified by 16S rRNA sequencing. Isolates from conjunctival surface were identified as Enterobacter spp., Staphylococcus spp. and S. aureus; and from aqueous humor samples as Enterobacter spp., Pantoea spp., Streptococcus spp. and Staphylococcus spp., respectively in decreasing order of prevalence. According to the rep-PCR analysis, 16.6% of Enterobacter spp. isolates from conjunctival surface were genetically similar to those from aqueous humor. The rest of isolates encountered in aqueous humor were genetically distinct from those of conjunctival surface. The significant genetic diversity of bacterial isolates found in the aqueous humor samples after surgery denoted the possibility of anterior chamber contamination during phacoemulsification by bacteria not only from conjunctival surface but also from different sources related to surgical environment.

Antibiotic prevention of postcataract endophthalmitis: a systematic review and meta-analysis

Endophthalmitis is one of the most feared complications after cataract surgery. The aim of this systematic review was to evaluate the effect of intracameral and topical antibiotics on the prevention of endophthalmitis after cataract surgery. A systematic literature review in the MEDLINE, CINAHL, Cochrane Library and EMBASE databases revealed one randomized trial and 17 observational studies concerning the prophylactic effect of intracameral antibiotic administration on the rate of endophthalmitis after cataract surgery. The effect of topical antibiotics on endophthalmitis rate was reported by one randomized trial and one observational study. The quality and design of the included studies were analysed using the Cochrane risk of bias tool. The quality of the evidence was evaluated using the GRADE approach. We found high-to-moderate quality evidence for a marked reduction in the risk of endophthalmitis with the use of intracameral antibiotic administration of cefazolin, cefuroxime and moxifloxacin, whereas no effect was found with the use of topical antibiotics or intracameral vancomycin. Endophthalmitis occurred on average in one of 2855 surgeries when intracameral antibiotics were used compared to one of 485 surgeries when intracameral antibiotics were not used. The relative risk (95% CI) of endophthalmitis was reduced to 0.12 (0.08; 0.18) when intracameral antibiotics were used. The difference was highly significant (p < 0.00001). Intracameral antibiotic therapy is the best choice for preventing endophthalmitis after cataract surgery. We did not find evidence to conclude that topical antibiotic therapy prevents endophthalmitis.

Residual lens cortex material: potential risk factor for endophthalmitis after phacoemulsification cataract surgery

PURPOSE

To evaluate the bacterial growth potential of residual lens cortex after phacoemulsification with the development of endophthalmitis.

SETTING

University medical center.

DESIGN

Experimental study.

METHOD

Staphylococcus aureus and Staphylococcus epidermidis were dispensed into aqueous humor or serial dilutions of lens cortex that were obtained from cataract patients during phacoemulsification. After a 24-hour incubation, the colony-forming unit (CFU) was quantified. Eighty rabbits had phacoemulsification. Complete lens cortex removal was performed in 40 rabbits, while a quarter of lens cortex was retained in 40 rabbits. Staphylococcus aureus, with an inoculum size of 32 CFU, 56.3 CFU, and 108.6 CFU, was injected intracamerally at the conclusion of surgery and the production of endophthalmitis was measured 72 h later. The aqueous and vitreous humor samples were collected for microbiological diagnosis.

RESULTS

The increase in bacterial growth of S aureus and S epidermidis was statistically significantly greater in each dilution of lens cortex than in aqueous humor (P < .001, Student t test). With inoculum of 32.0 CFU or 56.3 CFU of S aureus, there was a statistically higher incidence of bacterial culture-proven endophthalmitis in the residual lens cortex eye group than in the normal aphakic eye group (P < .05, Fisher exact test).

CONCLUSIONS

Lens cortex was associated with a significant increase in bacterial growth compared with aqueous humor. Therefore, eyes with residual lens cortex seem more prone to develop endophthalmitis if anterior chamber bacterial contamination occurs during phacoemulsification.

FINANCIAL DISCLOSURE

No author has a financial or proprietary interest in any material or method mentioned.