Pars Plana Vitrectomy With or Without Silicone Oil Endotamponade in Surgical Management of Endophthalmitis

The Role of Silicone Oil in the Surgical Management of Endophthalmitis: A Systematic Review

(1) Background: We aimed to systematically review the current literature to evaluate if in patients with postoperative endophthalmitis treated with pars plana vitrectomy, silicone oil tamponade could provide a useful contribution to the control and eradication of infection and if it could influence anatomical recovery and functional outcome. (2) Randomized controlled trials, cross-sectional studies, case series, and case reports published in the English language in peer-reviewed journals were included. No restriction was placed based on the study location. We used medical subject headings (MeSH) and text words. We searched MEDLINE (OVID and PubMed), Google Scholar, ISI Web of Science (Thom-on-Reuters), and the Cochrane Library (Wiley) from January 1995 to the present. To ensure literature saturation, we scanned the reference lists of included studies or relevant reviews identified through the search. Risk of Bias was assessed using the Newcastle-Ottawa scale for longitudinal studies and Cochrane risk-of-bias tool for randomized trials. (3) Results: abstracts of 75 articles were selected for full-text reading; after full-text reading, 44 articles were taken into consideration in the systematic review. 5 out of 7 in vitro experimental studies demonstrated antimicrobial activity against different species of bacteria and fungi. The use of SO as endotamponade associated with PPV led to better visual acuity and a lower rate of retinal detachment and the need for additional surgery. (4) Conclusions: Silicone oil reduces the risk of postoperative retinal detachment, especially in case of undetected retinal breaks, produces compartmentalization of the eye, may lead to early visual recovery, allows laser photocoagulation, prevents severe postoperative hypotony and has antimicrobic activity due to an inhibitory effect for several species of pathogens. Concerns regarding possible toxic effects on the retina and optic disc, compartmentalization and impaired washout of pathogen toxins have been reported. It may also influence intravitreal antibiotic distribution and clearance.

Complications associated with the use of silicone oil in vitreoretinal surgery: A systemic review and meta-analysis

Silicone oil (SO) still represents the main choice for long-term intraocular tamponade in complicated vitreoretinal surgery. This review compared the complications associated with the use of SO and other vitreous substitutes after pars plana vitrectomy in patients with different underlying diseases. Meta-analysis was conducted in accordance with PRISMA guidelines. We retrieved randomized clinical trials (RCTs), retrospective case-control and cohort studies evaluating the risk of using SO, published between 1994 and 2020, conducting a computer-based search of the following databases: PubMed, Web of Science, Scopus and Embase. Primary outcome was the rate of complications such as intraocular hypertension, retinal re-detachment, unexpected vision loss or hypotony. Secondary outcome was to compare the rate of adverse events of different SO viscosities, especially emulsification. Forty-three articles were included. There were significant differences in intraocular hypertension (p = 0.0002, OR = 1.66; 95% CI = 1.27-2.18) and the rate of retinal re-detachment (p < 0.0009, OR = 0.65; 95% CI = 0.50-0.64) between SO and other agents, including placebo. However, there were no differences in other complication rates. Silicone oil (SO)-emulsification rate was non-significantly higher in low than high SO viscosity, and results from other complications were comparable in both groups. The high quality of most of the studies included in this study is noteworthy, which provides some certainty to the conclusions. Among them is the high variability of the SO residence time. The fact that ocular hypertension and not hypotension is related to SO use. A clear relationship is not found for the so-called unexplained vision loss, which affects a significant percentage of eyes. Re-detachment cases are less if SO is used and that surprisingly there does not seem to be a relationship in the percentage of emulsification between the low- and high-viscosity silicones. All these data warrant more standardized prospective studies.

Mid-term safety and effectiveness of intravitreal dexamethasone implant to treat persistent cystoid macular edema in vitrectomized eyes for bacterial endophthalmitis

PURPOSE

To evaluate the mid-term safety and effectiveness of intravitreal dexamethasone implant (DEX-i) for treating unresponsive to medical therapy cystoid macular edema (CME) in vitrectomized eyes for endophthalmitis.

METHODS

Retrospective and interventional case series study conducted on vitrectomized eyes for endophthalmitis that developed a CME that did not adequately respond to medical therapy, who underwent 0.7-mg DEX-i. Main outcome measures were changes in central retinal thickness (CRT) and best corrected visual acuity (BCVA).

RESULTS

Eleven eyes were included in the study. Microbiological findings of vitreous biopsies were 7 (63.6%) staphylococcus epidermidis; 3 (27.3%) Pseudomonas aeruginosa; and 1 (9.1%) Propionibacterium acnes. Median (interquartile range, IqR) duration of CME was 4.0 (3.0-4.0) months. Median (IqR) time between vitrectomy and DEX-i was 9.0 (9.0-11.0) months. Median CRT was significantly decreased from 548.0 (412.8-572.5) µm at baseline to 308.0 (281.3-365.5) µm at month 6 (p = 0.0009, Friedman test). Median BCVA significantly improved from 38.0 (30.5-44.8) letters at baseline to 50.0 (46.8-53.0) letters at month 6 (p < 0.0001, Friedman), with 9 (81.8%) eyes gaining ≥ 10 letters. Elevation of intraocular pressure was observed in one (9.1%) eye, which was successfully controlled with medical therapy. No recurrence of endophthalmitis or other complications was observed. Eight (72.7%) eyes required an additional DEX-i, while 3 (27.3%) were successfully controlled with only one DEX-i. CME recurrence occurred in 5 (62.5%) Gram-positive and 3 (100.0%) Gram-negative bacteria (p = 0.2357).

CONCLUSION

In vitrectomized eyes for endophthalmitis affected by CME unresponsive to medical therapy, DEX-i had an acceptable safety profile and achieved favorable outcomes. The possibility of suppressing mechanisms for infection control should be taken into account, although correct management of endophthalmitis and long time without reactivation before DEX-i reduce the risk.

[Treatment of postoperative endophthalmitis : Operate or only inject?]

BACKGROUND

Postoperative endophthalmitis is among the most feared complications encountered after intraocular surgery. A prompt diagnosis and initiation of treatment are crucial for the visual prognosis, which also depends on the causative microorganism. Despite advances in prevention and the availability of more epidemiological data, most of the evidence for treatment dates back to a single study, the early vitrectomy study (EVS) carried out in the early 1990s. The EVS showed that vitrectomy with intravitreal antibiotics was superior to intravitreal antibiotics alone, only when visual acuity was light perception or below. The addition of systemic antibiotics did not have any benefits. Over the last 30 years, however, surgical techniques have continued to evolve and the medicinal options have also been expanded. Moreover, the EVS examined only endophthalmitis after cataract surgery and strictly speaking the results cannot be transferred to endophthalmitis from other causes.

OBJECTIVE

This review discusses the current evidence for the different treatment modalities of the most important types of postoperative endophthalmitis.

CONCLUSION

The EVS provided important guidelines for the initial management of endophthalmitis and these guidelines remain relevant to this day; however, in view of the refinement of surgical techniques, novel treatment options, especially the nowadays continuously growing number of intravitreal injections and even some new antibiotics, it would be desirable if new controlled trials addressing the treatment of endophthalmitis would be performed.

Surgical Management of Complications after Dexamethasone Implant

Purpose

To report surgical management of ocular complications occurred after dexamethasone (DEX) implant (Ozurdex®) injection.

Methods

Retrospective interventional case series.

Results

Different surgical procedures including viscoexpression to manage the migration of the implant into the anterior chamber, "phaco-rolling" technique for the intralenticular injection, and vitrectomy with implant removal for an acute endophthalmitis were performed. Successful management of different complications after DEX implant by using individualized surgical approaches was observed.

Conclusions

Early and targeted surgical management is required in selected cases of ocular complications after DEX implant. The implant removal was needed to preserve ocular anatomy and function.

Antibiotics and antifungals in silicone oil

Background

Antimicrobials may be injected into silicone oil-filled eyes with endophthalmitis, but the interaction with oil is unclear. The purpose of the experiment is to determine whether vancomycin, amikacin, and amphotericin B mix with silicone oil.

Methods

Using the relative proportions of the human eye, 4 ml of 1000 centistokes silicone oil was centrifuged with 0.1 ml of vancomycin 1 mg/0.1 ml, amikacin 0.4 mg/0.1 ml, or amphotericin B 5 µg/0.1 ml in vitro and eluted. The aqueous was immediately analyzed with a liquid chromatographer/mass spectrometer and after 24 h.

Results

Within 24 h, a mean of 26.9 μmol/L of vancomycin, 0 nmol/L of amikacin, and 0 nmol/L of amphotericin B were recovered. When the concentrations of amikacin and amphotericin B were increased 100-fold, 0 nmol/L of amikacin and 75.7 µmol/L of amphotericin B were recovered.

Conclusions

Vancomycin and amphotericin B partially mixed with the silicone oil. Amikacin was not recovered from the antibiotic–silicone oil mixture.

RISK OF SILICONE OIL AS VITREOUS TAMPONADE IN PARS PLANA VITRECTOMY: A Systematic Review and Meta-Analysis

PURPOSE

The authors examined the differences between silicone oil and other vitreous tamponades or placebo in performing pars plana vitrectomy.

METHODS

This review and meta-analysis was conducted in accordance with the PRISMA guidelines. Seven databases and the reference lists of the retrieved randomized controlled trial articles were searched to identify eligible studies. The primary outcomes were the rate of redetachment after endotamponade removal, the rate of reoperation, and poor visual acuity. The secondary outcomes were adverse events and quality of life related to postoperative position.

RESULTS

Ten articles (12 trials) were included. There were no significant differences between silicone oil and other agents in most of the primary and second outcomes. Only the risk of hypotony was found to be significantly lower when filling with silicone oil, compared with other agents. No trial reported the quality of life related to postoperative position.

CONCLUSION

Based on the available studies, the authors conclude that there is no significant difference in the risk of poor outcomes between pars plana vitrectomy with silicone oil and that with other vitreous tamponades with different surgical histories.

Visual Outcomes and Prognostic Factors after Pars Plana Vitrectomy for Traumatic Endophthalmitis

Purpose. To evaluate visual outcomes and identify prognostic factors after pars plana vitrectomy (PPV) surgery for traumatic endophthalmitis. Methods. Medical records of 121 consecutive patients (121 eyes) diagnosed with traumatic endophthalmitis that had undergone pars plana vitrectomy were retrospectively reviewed. Results. 121 patients, aged from 6 to 71 years, all underwent PPV surgery. 113 cases had improved best corrected visual acuity (BCVA) after surgery and 60% of them obtained BCVA better than fingers counting (FC). Good final visual prognosis was significantly associated with time between trauma and initial treatment less than 12 hrs (40% versus 98%; P < 0.001), time between trauma and PPV treatment less than 24 hrs (62% versus 98%; P < 0.001), laceration length less than 10 mm (63% versus 96%; P < 0.001), and presenting VA better than LP (42% versus 96%; P < 0.001), while gender, type of laceration, presence of IOFB or retinal detachment, and the use of silicone oil tamponade were not significant factors resulting in better BCVA. Bacteria were identified in 43.8% of specimens and most of the microorganisms were identified as nonvirulent ones. Conclusions. Pars plana vitrectomy surgery was preferred as a primary treatment option for traumatic endophthalmitis. A good final visual prognosis was significantly associated with timely treatment, prompt vitrectomy surgery, shorter length of laceration, and better presenting visual acuity.