Infectious and presumed noninfectious endophthalmitis after intravitreal triamcinolone acetonide injection

Ocular immunosuppressive microenvironment and novel drug delivery for control of uveitis

Ocular immune privilege is a phenomenon described by Peter Medawar in relation to the indefinite survival of the placement of foreign tissue grafts into the eye. Several mechanisms have been described that contribute to ocular immune privilege, such as a blood-ocular barrier and lack of lymphatics in the eye, the production of immune-suppressing molecules inside the ocular microenvironment, and the induction of systemic regulatory immunity against antigens found in the eye. Because ocular immune privilege is not absolute, failure of it can result in uveitis. Uveitis is a group of inflammatory disorders that can lead to vision loss if not treated properly. The current uveitis treatments involve the use of immunosuppressive and anti-inflammatory medications. Researching mechanisms of ocular immune privilege and the development of novel treatments for uveitis is ongoing. This review discusses mechanisms of ocular immune privilege, followed by an overview of uveitis treatments and ongoing clinical trials.

Safety Profile of Lutein- Versus Triamcinolone Acetonide-Based Vitreous Staining

Purpose

To assess the safety profile of a new lutein-based vitreous dye (LB-VD) formulation compared with various triamcinolone acetonide (TA) formulations with and without subsequent exposure to perfluorodecalin (PFD) in vitro.

Methods

Human adult retinal pigment epithelial cells (ARPE-19) were treated with the following formulations: undiluted preserved TA (TA-BA), diluted preserved TA (D-TA-BA), preservative-free TA (TA-PF), and LB-VD. First, cell tolerability was evaluated with MTT, LDH, and ATPlite assays after 1, 5, and 30 minutes of exposure to each tested formulation. Then, cells were sequentially exposed to formulations and PFD. After 24 hours of exposure to PFD, cell tolerability was evaluated through MTT and ATPlite assays.

Results

Among the formulations tested, LB-VD showed the highest levels of cell viability, cell metabolism, and cell proliferation and induced the lowest release of LDH, whereas the TA-based formulations demonstrated a cytotoxic effect on ARPE-19 cells in vitro. After subsequent 24-hour exposure to PFD, a greater reduction of cell viability was noted for all the formulations; however, this reduction was not significant only for the combination LB-VD-PFD, which was the best tolerated condition.

Conclusions

LB-VD showed a better safety profile compared with all TA-based formulations, even when used in combination with PFD.

Translational Relevance

In surgical practice, LB-VD may be preferred to TA-based formulations for vitreous staining in the light of its more favorable safety profile.

Ocular Injection Techniques for Retinitis Pigmentosa: Intravitreal, Subretinal, and Suprachoroidal

Ocular gene therapy represents an emerging and promising therapeutic approach for the treatment of several of the inherited retinal diseases. Currently, the focus has been to investigate monogenic inherited retinal disorders. Genetic and cellular therapies can be delivered to the eye by various injection techniques, including those that are intravitreal, subretinal, and suprachoroidal. Each of these three delivery methods are discussed with regard to their historical background, indications, surgical steps, and follow-up.

Preventive factors, diagnosis, and management of injection-related endophthalmitis: a literature review

BACKGROUND

Intravitreal medication injections represent the gold standard treatment for a variety of potentially blinding chorioretinal vascular diseases. Despite their excellent safety profile, they are associated with the feared complication of injection-related endophthalmitis (IRE). Though the overall incidence of IRE is low, due to the ever-increasing number of injections being performed, it is a complication that all retina specialists are likely to encounter. This article reviews various factors that could potentially influence the risk of IRE and discusses evidence-based strategies for management.

METHOD

PubMed was searched for keywords "intravitreal injection" and "endophthalmitis" from the period of 1995-2021. Relevant articles were reviewed and selected articles were analyzed with respect to the incidence, potential preventive factors, clinical presentation, microbial profile, management, and outcomes for IRE.

RESULTS

There is strong consensus supporting the use of povidone iodine topical antiseptic, eyelid retraction away from the injection site, and avoiding treatment of eyes with active surface or eyelid disease, but there is less agreement on the use of face masks versus "no-talking" policies and optimal anesthetic technique. Current evidence comparing tap and inject or early vitrectomy for treatment of IRE is inadequate to determine an optimal treatment strategy.

CONCLUSION

Intravitreal injections are sight saving, but even using established prophylactic measures there remains a small but real risk of infectious injection-related complications. Further investigations comparing tap and inject versus vitrectomy may help to establish optimal treatment, although the rarity of IRE makes designing adequately powered prospective trials a difficult task.

Complications of intravitreal injections: 2022

PURPOSE OF REVIEW

This review highlights the complications of both intravitreal injection procedure as well as different intravitreal medications including antivascular endothelial growth factors, antibiotics, antivirals, antifungals, methotrexate, and steroids. Techniques for reducing rates of endophthalmitis will also be discussed.

RECENT FINDINGS

Intravitreal vancomycin can cause hemorrhagic occlusive retinal vasculitis resulting in severe vision loss. Intravitreal brolucizumab is associated with intraocular inflammation and retinal vasculitis resulting in significant vision loss. Face mask use by both patient and physician is not associated with increased risk of endophthalmitis and may decrease culture positive endophthalmitis.

SUMMARY

Intravitreal injections continue to be one of the most commonly performed procedures by ophthalmologists. Although the injections are generally well tolerated, sight-threatening complications can occur including endophthalmitis, retinal detachment, and/or retinal vasculitis. Adverse events associated with specific medications are outlined below. Several safety measures have been shown to reduce rates of endophthalmitis, the most concerning complication of this procedure.

Sterile endophthalmitis after intravitreal triamcinolone acetonide injection: A case report series

Corticosteroids have proven their effectiveness in the treatment of cystoid macular edema. Especially after an intravitreal injection. Triamcinolone acetonide is the most commonly used in the treatment of macular edema. Noninfectious endophthalmitis is a form of endophthalmitis that can occur in the absence of a defined germ after an intravitreal injection of triamcinolone acetonide.

We report here the case of three diabetic patients, who presented with visual blur, three days after an intra vitreal triamcinolone acetonide injection performed in the right eye.

The vitreous inflammation resolved spontaneously in the first two cases after three weeks, and after four weeks for the third. The diagnosis of sterile endophthalmitis was made in view of the spontaneous resolution of the inflammation without the use of intravitreal injection of antibiotics and/or vitreoretinal surgery.

•

Describe the development of sterile endophthalmitis after an intravitreal injection of triamcinolone acetonide in diabetic patients with macular edema.

•

Enhance the differences between infections endophthalmitis and sterile endophthalmitis.

•

Report our ophthalmology team's management in front of a sterile endophthalmitis in comparison to literature.

Practice patterns regarding regional corticosteroid treatment in noninfectious Uveitis: a survey study

Background

Regional corticosteroid therapy for noninfectious uveitis is well-established but usage patterns have not been studied extensively. This study aims to assess practice patterns of retina and uveitis specialists regarding their preferences on the use of local corticosteroid therapy.

Methods

A 13-question survey was developed regarding the practice patterns of regional corticosteroid use in specific situations and populations. The survey was distributed to both the American Uveitis Society and Macula Society.

Results

Responses from 87 ophthalmologists were analyzed. The two most commonly used drugs were the dexamethasone intravitreal implant (Ozurdex®) and posterior sub-tenon’s triamcinolone (also known as posterior sub-Tenon’s Kenalog, or PSTK). Regional corticosteroids were used more frequently as first-line treatment in more than half of posterior uveitis cases when compared to anterior uveitis (39.1–46.0% vs 10.3%, respectively). Respondents were more willing to use regional corticosteroids in more than half of unilateral uveitis cases than in bilateral cases (54.7% vs 18.6%, respectively). A majority of respondents (67.1%) stated that they would avoid using regional corticosteroids in patients under 8 years old.

Conclusions

Our results demonstrate more frequent regional corticosteroid use in posterior segment uveitis, unilateral cases, and avoidance in younger pediatric patients. Overall, the variability in these responses highlights the need for guidelines regarding regional corticosteroid use.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12348-021-00281-z.

A Review of Ocular Drug Delivery Platforms and Drugs for Infectious and Noninfectious Uveitis: The Past, Present, and Future

Uveitis refers to a broad group of inflammatory disorders of the eye that often require medical and surgical management to improve or stabilize vision and prevent vision-threatening pathological changes to the eye. Drug delivery to the eye to combat inflammation and subsequent complications from uveitic conditions is complex as there are multiple barriers to absorption limiting availability of the needed drug in the affected tissues. As such, there has been substantial interest in developing new drugs and drug delivery platforms to help reduce intraocular inflammation and its complications. In this review, we discuss the challenges of drug delivery, novel technologies recently approved for uveitis patient care and promising drug delivery platforms for uveitis and sequelae of ocular inflammation.

Lipid-Based Nanocarriers for Ophthalmic Administration: Towards Experimental Design Implementation

Nanotherapeutics based on biocompatible lipid matrices allow for enhanced solubility of poorly soluble compounds in the treatment of ophthalmic diseases, overcoming the anatomical and physiological barriers present in the eye, which, despite the ease of access, remains strongly protected. Micro-/nanoemulsions, solid lipid nanoparticles (SLN) or nanostructured lipid carriers (NLC) combine liquid and/or solid lipids with surfactants, improving drug stability and ocular bioavailability. Current research and development approaches based on try-and-error methodologies are unable to easily fine-tune nanoparticle populations in order to overcome the numerous constraints of ocular administration routes, which is believed to hamper easy approval from regulatory agencies for these systems. The predictable quality and specifications of the product can be achieved through quality-by-design (QbD) implementation in both research and industrial environments, in contrast to the current quality-by-testing (QbT) framework. Mathematical modelling of the expected final nanoparticle characteristics by variation of operator-controllable variables of the process can be achieved through adequate statistical design-of-experiments (DoE) application. This multivariate approach allows for optimisation of drug delivery platforms, reducing research costs and time, while maximising the understanding of the production process. This review aims to highlight the latest efforts in implementing the design of experiments to produce optimised lipid-based nanocarriers intended for ophthalmic administration. A useful background and an overview of the different possible approaches are presented, serving as a starting point to introduce the design of experiments in current nanoparticle research.

Comparative study on pharmacokinetics and toxicity of intravitreal and sub-Tenon injection of triamcinolone acetonide in ocular tissues

AIM

To compare the differences in kinetics, distribution, and toxicity of triamcinolone acetonide (TA) between the injection methods, sub-Tenon and intravitreal injections in rabbit ocular tissues.

METHODS

TA was injected into the vitreous or the sub-Tenon in rabbits. For pharmacokinetic study, rabbits were sacrificed periodically and then TA in blood and ocular tissues (retina/choroids, vitreous, and aqueous humor) were measured over 91d. For toxicological study, clinical signs, slit-lamp microscopic examination, ophthalmological test were performed. The eyeballs and surrounding tissues were collected and fixed with glutaraldehyde-formalin solution, and then paraffin embedded for histological investigation.

RESULTS

Higher levels of TA were distributed in the intraocular tissues when injected into the vitreous compared to the sub-Tenon. Conversely, TA level was remarkably lower in the rabbits which received intravitreal TA injections than those treated with sub-Tenon injection throughout the study period in plasma. Optical discharge probably caused by systemic circulation of TA was observed by receiving sub-Tenon TA injection. Meanwhile, technic-associated toxicological ocular symptoms and findings were more frequently observed in intravitreal injection than in sub-Tenon injection.

CONCLUSION

There are significant differences in kinetics and distribution of TA in vitreous body, aqueous humor and plasma, between the two injection methods. Although further study is needed to explain the species difference between human and rabbit, it is assumed that the difference in the frequency of intraocular pressure elevation and cataract formation by TA between the two injection methods are directly related to the TA concentrations in aqueous humor and vitreous body in each injection methods. Systemic toxicity and technic-associated toxicity are also closely related to kinetics of TA in plasma and each injection method itself, respectively.

Noninfectious endophthalmitis following intravitreal triamcinolone acetonide: clinical case and literature review

OBJECTIVE

To review the literature on noninfectious endophthalmitis (NIE) following intravitreal triamcinolone acetonide (IVTA).

DESIGN

A literature review and case report.

PARTICIPANTS

Individuals who developed NIE after IVTA injection.

METHODS

A review of the literature was undertaken using Ovid MEDLINE and EMBASE databases, and articles available up to and including December 30, 2019, were included. A total of 518 articles were identified, of which 27 were selected. We also present an illustrative case report.

RESULTS

The incidence rate of NIE lies between 0.1% and 7.3% in most studies. Although the etiology of NIE is still the subject of investigation, proposed mechanisms include excipients and rheologic stress caused by small crystals. The time to presentation of NIE is often 1-3 days after IVTA injection, with symptoms of moderate to marked reduction in visual acuity along with signs of anterior chamber inflammatory reaction, hypopyon, and vitritis. Resolution occurs in 1-3 weeks in the majority of patients, and almost all return to their pre-injection visual acuity. Differences in the presentations of NIE, infectious endophthalmitis, and pseudo-endophthalmitis are discussed. We also present an illustrative case report of an 80-year-old woman who developed NIE after an IVTA injection for cystoid macular edema.

CONCLUSIONS

It is important to distinguish NIE from other forms of endophthalmitis because they have different natural histories and require different interventions and follow-up. NIE is rarely accompanied by significant pain or conjunctival erythema. Visual acuity is inconsistently affected and is therefore not a good criterion for identifying the type of presenting endophthalmitis.

[Vitrectomy for endophthalmitis : Incubation time and prognosis following intravitreal injection vs. cataract surgery]

BACKGROUND

Bacterial endophthalmitis is a rare but devastating complication following intraocular surgery. Guidelines on the diagnostics and treatment are based mainly on experience of endophthalmitis treatment following cataract surgery.

OBJECTIVE

In this study we analyzed infectious endophthalmitis cases following either intravitreal operative drug injection (IVOM) or cataract surgery for possible differences in the clinical course and prognosis.

MATERIAL AND METHODS

All cases of endophthalmitis from January 2013 through December 2017 retrieved from our electronic database were examined and analyzed according to the type of intervention, time elapsed until diagnosis, pathogen detection, postinterventional visual acuity and the presence of comorbidities.

RESULTS

A total of 29 cases were included, 11 secondary to IVOM and 18 secondary to cataract surgery. Symptoms for all cases presented at a mean of 6.8 days, with a significant difference between patients following IVOM (5.5 days) and patients following cataract surgery (4.1 days, p < 0.05). Patients with endophthalmitis following cataract surgery had a significantly better visual outcome 1 year after treatment compared to patients with endophthalmitis following IVOM (p < 0.05). The most commonly isolated pathogen was Staphylococcus epidermidis.

CONCLUSION

Knowledge of the typical clinical course in the development of endophthalmitis following IVOM or cataract surgery is a critical prerequisite for the timely diagnosis and initiation of adequate treatment measures. Our results point towards a significantly delayed clinical manifestation of endophthalmitis following IVOM, possibly also caused by the anatomical origin of the infection. In an era of increasing numbers of IVOM this clinical observation could be helpful for a careful follow-up control beyond the previous traditional timepoints.

Intravitreal therapeutic agents in noninfectious uveitic macular edema

The management of uveitis is challenging for most treating ophthalmologists. The treatment of uveitis often requires the use of high dose of systemic corticosteroid and immunosuppressive agents, which are almost always associated with potential side effects. Intravitreal medications have become a popular mode of drug administration in uveitis patients as they provide high volume of drug to the target tissues, eliminating the risk of systemic toxicity. There has been tremendous development in the intravitreal therapeutics over the last few years. With the advent of sustained-release technique, increasing patient compliance, biodegradable nature of the implant, and introduction of newer agents with better safety profile, the intravitreal medications have become more popular in recent years. This review presents evidence in the scientific literature supporting the use of intravitreal medications for the management of uveitis and its complications.

Vitreous opacities after intravitreal triamcinolone injection- a case report

Background

We report occurrence of peculiar tiny white thread like vitreous opacities after intravitreal triamcinolone injection. These persisted without any change for over a year. We ascribe them to aggregation of triamcinolone crystals due to the purification methods.

Case presentation

Seven patients (8 eyes) with macular edema developed tiny whitish thread like opacities in the vitreous 2–3 months after undergoing an intravitreal injection of triamcinolone acetonide preparation containing benzyl alcohol as preservative. These opacities persisted unchanged for more than a year. The follow up ranged from 91 to 425 days. Vitreous tap was done in one patient which was negative for infection. All patients initially showed improvement but needed re-treatment for recurrence. One patient developed steroid induced rise in intraocular pressure. Microscopic examination of the drug revealed large string like aggregates of triamcinolone crystals.

Conclusions

We hypothesize the possibility of aggregation of triamcinolone crystals into string like structures probably due to the purification methods used during manufacture which led to these thread like opacities in the vitreous.

Verteporfin Therapy and Triamcinolone Acetonide: Convergent Modes of Action for Treatment of Neovascular Age-Related Macular Degeneration

PURPOSE

Choroidal neovascularization associated with age-related macular degeneration is the primary cause of blindness in the elderly in developed countries, due to a number of pathogenic effects, including angiogenesis, cell-mediated inflammation, leukocyte adhesion and extravasation, and matrix remodeling.

METHODS

By producing photochemical effects at the site of target tissue (lesion), photodynamic therapy (PDT) can induce vascular damage and blood flow stasis, leading to occlusion of vascularization and lesion leakage.

RESULTS

PDT with verteporfin (Visudyne, Novartis) has been shown to be safe and effective in reducing the risk of vision loss in patients with classic containing subfoveal CNV and occult with no classic CNV. However, in predominantly occult CNV, the treatment may be most effective in smaller lesions, and less in larger lesions. Most important, visual acuity rarely is improved.

CONCLUSIONS

Pilot studies and large case series suggest that a combination of PDT and intravitreal triamcinolone acetonide has the potential to improve visual outcomes and reduce the need for additional treatments. Randomized, prospective clinical trials are underway to confirm the efficacy and safety of this novel treatment modality.

Intravitreal Triamcinolone Acetonide in Refractory Pseudophakic Cystoid Macular Edema: Functional and Anatomic Results

PURPOSE

To evaluate safety and efficacy of intravitreal triamcinolone acetonide (TAAC) injections in the treatment of refractory pseudophakic cystoid macular edema (CME).

METHODS

Seven eyes of six patients (age range: 50-74) with pseudophakic CME resistant to standard treatment received intravitreal injections of 4 mg of TAAC with all vehicle. Mean preinjection duration of CME was 18.3 months. A mean of 2.1+/-1.2 (range 1 to 4) treatments were performed in four eyes (57.1 %) when visual acuity deteriorated towards baseline levels. Visual acuity assessment, optical coherence tomography (OCT), and fluorescein angiography (FFA) were performed pre- and postoperatively to evaluate results of TAAC injections. Intraocular pressure (IOP) and complications related to treatment were assessed.

RESULTS

After 11.1+/-3.9 months, mean best-corrected visual acuity (BCVA) increased (p =0.019) from 20/132 to a best value of 20/38. Mean macular thickness decreased from 517.29+/-146.98 mm to a best value of 263.71+/-83.13 mm (p=0.0018). Area of fluorescein leakage decreased (p<0.0001) from 11.84+/-0.93 mm2 at baseline to a minimal value of 3.86+/-0.98 mm2. The anatomic and functional improvement appeared after 1 month from the intravitreal injection and persisted through at least 3 months of follow-up. At the end of follow-up BCVA, macular thickness, and area of fluorescein leakage did not differ from baseline. Four eyes (57.1 %) developed IOP values higher than 21 mmHg, controlled by topical treatment. Two patients developed an endophthalmitis-like reaction.

CONCLUSIONS

Intravitreal TAAC was relatively safe and effective in resistant cases of pseudophakic CME with a temporary beneficial effect on visual acuity and macular edema.

The Efficacy of a Posterior sub-Tenon’s Capsule Triamcinolone Injection in Patients with Non-infectious Intermediate Uveitis and Posterior Uveitis

To investigate the efficacy of a posterior sub-Tenon’s capsule triamcinolone injection for treating eyes with non-infectious posterior and intermediate uveitis.

A total of 31 eyes from 20 patients with non-infectious posterior uveitis and 18 eyes from 10 patients with non-infectious intermediate uveitis that inadequately responded to treatment with systemic corticosteroids and second-line immunosuppressive agents were enrolled in the study. All patients received a posterior sub-Tenon’s injection of 20 mg/ml triamcinolone. The parameters we examined included the following: best corrected visual acuity, central foveal thickness, fluorescein angiography score and intraocular pressure.

The mean best corrected visual acuity was significantly improved from the control visit, 0.15±0.30 logMAR (Snellen equivalent 0.7), compared to the baseline measurements, 0.60±0.30 logMAR (Snellen equivalent 0.25; P<0.05). The mean central foveal thickness (CFT) and the mean score for fluorescein angiography (FA) were significantly decreased from the baseline (CFT: 320±34 μm; FA mean score: 5.9±1.9) compared to the twelve-week control visit (CFT: 235±30 μm; FA mean score: 1.2±1.1; P<0.001). Five eyes had intraocular pressure spikes that required a topical anti-glaucomatous treatment.

A posterior sub-Tenon’s injection of triamcinolone can significantly improve visual acuity and decrease macular oedema in patients with non-infectious posterior and intermediate uveitis. Complications were minimal, and there were no eyes that required surgical treatment for elevated intraocular pressure. The results suggest that the posterior sub-Tenon’s injection of triamcinolone is an important form of therapy for non-infectious posterior and intermediate uveitis.

Facilitation of transscleral drug delivery by drug loaded magnetic polymeric particles

A unique method was used to facilitate ocular drug delivery from periocular route by drug loaded magnetic sensitive particles. Injection of particles in periocular space along the eye axis followed by application of magnetic field in front of the eye would trigger the magnetic polymeric particles to move along the direction of magnetic force and reside against the outer surface of the sclera. This technique prevents removal of drug in the periocular space, observed in conventional transscleral drug delivery systems and hence higher amount of drug can enter the eye in a longer period of time. The experiments were performed by fresh human sclera and an experimental setup. Experimental setup was designed by side by side diffusion cell and hydrodynamic and thermal simulation of the posterior segment of the eye were applied. Magnetic polymeric particles were synthesized by alginate as a model polymer, iron oxide nanoparticles as a magnetic agent and diclofenac sodium as a model drug and characterized by SEM, TEM, DLS and FT-IR techniques. According to the SEM images, the size range of particles is around 60 to 800nm. The results revealed that the cumulative drug transfer from magnetic sensitive particles across the sclera improves by 70% in the presence of magnetic field. The results of this research show promising method of drug delivery to use magnetic properties to facilitate drug delivery to the back of the eye.

Clinical Outcomes of Intravitreal Preservative-Free Triamcinolone Preparation (Triesence®) for Cystoid Macular Oedema and Inflammation in Patients with Uveitis

PURPOSE

To assess the outcomes of intravitreal benzyl alcohol-free triamcinolone acetonide suspension in uveitis-related macular oedema.

METHODS

Single-center retrospective cohort study of 66 injections to 44 eyes of 40 patients. Uveitis diagnosis, systemic and local therapy, intraocular pressure (IOP), central retinal thickness (CRT), number of injections, time to re-injection and side-effects were noted during 6-months minimum follow-up.

RESULTS

Sixty eight percent of eyes received a single injection. 18% required 2 injections, and 13% received ≥3 injections with mean time to second and third injections of 25.5 and 52.7 weeks, respectively. 90% of injections were unilateral. Mean CRT reduced, and by 12-weeks visual acuity improvement >0.3logMar was achieved in 46%. Cataract progression (47%) and IOP>21 mmHg (45%) were the commonest adverse events.

CONCLUSION

Preservative-free triamcinolone is an additional option for uveitis-related macular oedema, particularly in unilateral cases, with favorable CRT and visual outcomes. Repeat injections may be necessary, and the period of efficacy varies between eyes.

ENDOPHTHALMITIS AFTER INTRAVITREAL INJECTION: Role of Prophylactic Topical Ophthalmic Antibiotics

PURPOSE

To determine the rate of postintravitreal injection endophthalmitis and to assess microbiological features and outcomes with and without the use of peri-intravitreal injection topical ophthalmic antibiotics.

METHODS

Consecutive series of endophthalmitis cases retrospectively identified after intravitreal injection at a multicenter, retina-only referral practice (Retina Consultants of Houston) from January 1, 2011 to December 31, 2014. Prophylactic peri-intravitreal injection topical antibiotics were routinely used during the initial 12-month period (January 1, 2011-December 31, 2011) and not used in the final 24-month period (January 1, 2013-December 31, 2014). Main outcome measures were incidence of endophthalmitis, microbiology results, treatment strategies, and visual outcomes.

RESULTS

Of 90,339 intravitreal injections, 30 cases of endophthalmitis were identified (endophthalmitis rate = 0.033%; 95% confidence interval, 0.021-0.045%; or approximately 1 of 3,011 intravitreal injections). The most common organisms isolated were coagulase-negative staphylococci (n = 10, 33%), followed by Streptococcus mitis (n = 2, 7%). Fourteen cases (47%) were culture negative. Peri-intravitreal injection topical antibiotic prophylaxis did not decrease the rate of endophthalmitis (0.035% [95% CI, 0.007-0.064%] with antibiotic use versus 0.021% [95% CI, 0.008-0.033%] without antibiotic use; P = 0.261).

CONCLUSION

The risk of endophthalmitis after intravitreal injection remains low, with coagulase-negative staphylococci and Streptococcus mitis the most common bacterial isolates identified. Prophylactic peri-intravitreal injection topical ophthalmic antibiotic use did not decrease the endophthalmitis rate.

Infectious and sterile endophthalmitis after intravitreal injections: differential diagnosis, prevention, treatment

Endophthalmitis is a rare but extremely severe complication of different intraocular procedures. In the article, we analyze world literature data on prevalence, differential diagnosis, prevention methods, and treatment of endophthalmitis after intravitreal injections.

Bilateral Severe Sterile Inflammation with Hypopyon after Simultaneous Intravitreal Triamcinolone Acetonide and Aflibercept Injection in a Patient with Bilateral Marked Rubeosis Associated with Ocular Ischemic Syndrome

We report the clinical course of a diabetic patient with bilateral cataract and rubeosis in association with ocular ischemic syndrome and initially treated him with simultaneous intravitreal 2 mg aflibercept and 2 mg triamcinolone acetonide injection at the same setting prior to planned cataract surgery and further photocoagulation. However, sterile anterior segment inflammation characterized by hypopyon occurred four days apart in OU. Right eye developed the sterile inflammation at the third postinjection day and the left eye developed the sterile inflammation at the seventh postinjection day (two days after the uneventful cataract surgery with intraocular lens implantation) without any pain or significant redness. Vitreous biopsy taken during the right phacovitrectomy was negative for any microbial contamination. Both eyes were treated successfully with intensive topical prednisolone acetate with a relatively good visual outcome. It is likely that underlying ocular ischemic syndrome might have facilitated the formation of sterile inflammation as blood-aqueous barrier disruption and flare have already been present.

Short-term efficacy of intravitreal triamcinolone acetonide for macular edema secondary to retinal vein occlusion that is refractory to intravitreal bevacizumab

AIMS

To evaluate the 1-month efficacy of intravitreal triamcinolone acetonide (TA) in treating macular edema secondary to retinal vein occlusion (RVO) that was refractory to intravitreal bevacizumab.

MATERIALS AND METHODS

This retrospective, observational study included 23 eyes from 23 patients with macular edema secondary to RVO. Macular edema that did not respond to two or more consecutive intravitreal bevacizumab injections was treated with intravitreal TA. Central foveal thickness (CFT) and best-corrected visual acuity (BCVA) were compared before and one month after TA injection.

RESULTS

Fifteen eyes were diagnosed with central RVO, and eight eyes were diagnosed with branch RVO. All patients were previously treated with 2.4 ± 0.6 intravitreal bevacizumab injections. The TA injection was performed, on average, 5.8 ± 1.4 weeks after the last bevacizumab injection. The CFT before TA injection was 516.6 ± 112.4 μm and significantly decreased to 402.3 ± 159.7 μm after TA therapy (P < 0.001). The logarithm of the minimal angle of resolution BCVA was 0.72 ± 0.34 before TA therapy and was not significantly improved by the treatment (0.67 ± 0.35, P = 0.119), despite a decrease in CFT. However, seven eyes (30.4%) had a BCVA gain of one or more lines.

CONCLUSIONS

Intravitreal TA therapy was beneficial in some patients with macular edema secondary to RVO that was refractory to intravitreal bevacizumab therapy. This study suggests that intravitreal TA should be considered as a treatment option for refractory macular edema.

Diabetic retinopathy

Diabetic retinopathy (DR) is a common complication of diabetes mellitus and is a major cause of vision loss in middle-aged and elderly people. One-third of people with diabetes have DR. Severe stages of DR include proliferative DR, caused by the abnormal growth of new retinal blood vessels, and diabetic macular oedema, in which there is exudation and oedema in the central part of the retina. DR is strongly associated with a prolonged duration of diabetes, hyperglycaemia and hypertension. It is traditionally regarded as a microvascular disease, but retinal neurodegeneration is also involved. Complex interrelated pathophysiological mechanisms triggered by hyperglycaemia underlie the development of DR. These mechanisms include genetic and epigenetic factors, increased production of free radicals, advanced glycosylation end products, inflammatory factors and vascular endothelial growth factor (VEGF). Optimal control of blood glucose and blood pressure in individuals with diabetes remains the cornerstone for preventing the development and arresting the progression of DR. Anti-VEGF therapy is currently indicated for diabetic macular oedema associated with vision loss, whereas laser photocoagulation prevents severe vision loss in eyes with proliferative DR. These measures, together with increasing public awareness and access to regular screening for DR with retinal photography, and the development of new treatments to address early disease stages, will lead to better outcomes and prevent blindness for patients with DR.

Study of the Acute Effects of Povidone-Iodine on Conjunctival Bacterial Flora

PURPOSE

The purpose of this laboratory study was to assess the effect of povidone-iodine (PI) use topically on the conjunctiva in regard to needle bore contamination and to compare these results with our previous findings from an evaluation of bacterial contamination following gatifloxacin and moxifloxacin administration.

METHODS

We performed 100 conjunctival 27-gauge needle penetrations of both eyes of 13 fresh cadavers. Eyes were then soaked in 10% PI, after which conjunctiva was again penetrated 100 times. After conjunctival penetration, the needles were irrigated, and the irrigant was assessed for bacterial growth. Results were compared with previous work assessing fluoroquinolone effectiveness through the same model.

RESULTS

We observed a 28% (P = 0.003) decrease in bacterial growth and 40% (P < 0.0001) decrease in colony counts after PI placement. Differences between the effect of PI versus moxifloxacin and gatifloxacin were not statistically significant.

CONCLUSIONS

There is a greater decrease in bacterial load after treatment with PI for surface cultures than for cultures obtained through a needle bore passed through the conjunctiva. PI is a superior approach to topical antibiotics to decrease conjunctival bacterial load.

The Association between Intravitreal Steroids and Post-Injection Endophthalmitis Rates

PURPOSE

To determine whether there is a difference in the risk of endophthalmitis after an intravitreal steroid injection compared with an anti-vascular endothelial growth factor (VEGF) agent injection.

DESIGN

Retrospective cohort study.

PARTICIPANTS

A total of 75,249 beneficiaries in a large national US medical claims database representing 406 380 intravitreal injections.

METHODS

Data were searched for all intravitreal injections (Current Procedural Terminology 67028) performed between 2003 and 2012. Cohorts were created on the basis of injections using anti-VEGF agents (bevacizumab, ranibizumab, aflibercept, and pegaptanib) and intraocular steroids (triamcinolone and dexamethasone). Endophthalmitis was defined as having a new endophthalmitis diagnosis (International Classification of Diseases 9th Revision 360.0x) and a "tap-and-inject" procedure (Current Procedural Terminology 67015, 67025), a vitrectomy (67036), or an intravitreal antibiotic injection on the same day, between 1 and 14 days post-injection. Exclusion occurred for any history of endophthalmitis, <6 months in the plan, or <1 month follow-up. The main outcome measure was the odds of endophthalmitis using logistic regression while controlling for injection-associated diagnosis, age, race, and gender.

RESULTS

A total of 387,714 anti-VEGF injections and 18 666 steroid intravitreal injections were performed and followed by 73 (rate=0.019% or 1/5283 anti-VEGF injections) and 24 (rate=0.13% or 1/778 steroid injections) cases of endophthalmitis, respectively. After controlling for diagnosis, age, race, and gender, the odds ratio (OR) for endophthalmitis occurring was 6.92 (95% confidence interval, 3.54-13.52, P<0.001) times higher post-steroid injection compared with anti-VEGF injections.

CONCLUSIONS

The rate of endophthalmitis post-intravitreal steroid injection in a national cohort was 0.13% (1/778 injections). This rate conferred a significantly increased OR of 6.92 for endophthalmitis compared with anti-VEGF agents.

The effectiveness and reliability of posterior sub-Tenon triamcinolone acetonide injection in branch retinal vein occlusion-related macular edema

OBJECTIVE

To investigate the effectiveness and reliability of posterior sub-Tenon triamcinolone acetonide (PSTA) application in branch retinal vein occlusion (BRVO)-related macular edema.

METHODS

Patients with confirmed BRVO-related macular edema were enrolled in the study. Patients were injected with a single, therapeutic dose of 40 mg PSTA. Detailed ophthalmic examination was performed at baseline and at 1, 3 and 6 months after the treatment. Best corrected visual acuity (BCVA), intraocular pressure (IOP), cataractogenic change (CC) and macular optical coherence tomography (OCT) analysis results were evaluated. The results were compared statistically.

RESULTS

Forty-one eyes of 41 patients with a mean age of 63.49 ± 10.99 (55-86) years, 15 (36.6%) females, were included in the study. BCVA in LogMAR values at 1 and 3 months were significantly better than at baseline, while no significant difference from baseline was observed in sixth month values (p < 0.001, p < 0.001 and p = 0.846, respectively). Central macular thickness values obtained using OCT were significantly lower at the first, third and sixth months compared to baseline (p < 0.001 for all). IOP elevation was determined in only two eyes (4.8%) at the end of the study period, and no CC was detected in any case.

CONCLUSION

PSTA application is an effective and safe option in BRVO-related macular edema.

Safety and Efficacy of Intravitreal Preservative-Free Triamcinolone Acetonide (Triesence) for Macular Edema

PURPOSE

To evaluate the efficacy and safety of preservative-free triamcinolone acetonide (Triesence) for the treatment of macular edema.

METHODS

A retrospective study was conducted on patients who attended a tertiary retinal clinic from June 2009 to July 2012 with macular edema due to various causes. Patients who received at least 1 intravitreal Triesence injection and completed 6 months of follow-up were recruited. Data, including best-corrected Snellen visual acuity, central macular thickness (CMT), intraocular pressure (IOP), and adverse events (AEs), were collected at baseline, week 1, month 1, month 3, and month 6 after initiation of treatment. Snellen visual acuity was converted to visual acuity score (VAS) for statistical analysis using paired t-tests and linear regression.

RESULTS

One hundred two eyes from 102 patients were included in the study. Mean VAS was significantly improved at all follow-up time points compared to baseline (P≤0.002), with highest mean gain at month 1 (6.1±8.9 letters). Mean CMT decreased significantly at all follow-up points compared to baseline (P≤0.0005), with the greatest reduction at week 1 (146.6±109.4 μm). A total of 22 AEs were observed, and IOP elevation was the most common AE related to Triesence treatment (17/22, 77.3%). No sterile or infectious endophthalmitis was observed.

CONCLUSION

Intravitreal Triesence improves visual acuity and reduces macular thickness in eyes with macular edema from various causes. Treatment-associated IOP elevation was manageable with antiglaucoma medications. There were no serious vision-threatening complications associated with intravitreal Triesence therapy during the study period.

Sterile endophthalmitis rates and particle size analyses of different formulations of triamcinolone acetonide

PURPOSE

To evaluate the rate of sterile endophthalmitis (SE) following intravitreal injection of three different formulations of triamcinolone acetonide (TA) in a single physician practice and also to assess the mean diameter and concentration of particles of the two TA formulations currently available commercially in the USA. It was hypothesized that TA formulations with smaller particles and/or greater concentrations would have a higher incidence of SE.

METHODS

Single-site, interventional case series in which the medical records of 392 consecutive eyes receiving intravitreal TA as Triesence(®), Kenalog(®)-40, or preservative-free TA between September 2008 and October 2013 were retrospectively reviewed for the incidence of SE. Particle sizing of TA formulations was conducted by an independent commercial laboratory.

RESULTS

Five cases of SE were identified. The four cases of SE following Triesence(®) (4.6%) represented a rate significantly higher than the one case of SE following preservative-free TA (0.6%; P=0.049) and the 0% incidence rate of SE following Kenalog(®)-40 (P=0.0210). Triesence(®) had significantly smaller particles than Kenalog(®)-40 (P<0.0001).

CONCLUSION

The rate of SE was the highest with the formulation of TA that had the smallest particle size and highest particle load (number of particles injected). The lowest rate of SE was seen with Kenalog(®)-40, the only TA formulation that contained a benzyl alcohol preservative. The data do not support a principal causative role of benzyl alcohol in the development of TA-induced SE. Instead, the data support the particle theory of TA-induced SE; however, larger-scale, multicenter studies are needed to confirm and expand on these findings.

Comparison of the effects of intravitreal bevacizumab and triamcinolone acetonide in the treatment of macular edema secondary to central retinal vein occlusion

AIM

To compare the effects of intravitrealbevacizumab (IVB) and intravitreal triamcinolone acetonide (IVT) in the treatment of macular edema (ME) secondary to central retinal vein occlusion (CRVO).

MATERIALS AND METHODS

There were 20 patients treated with IVB (1.25 mg/0.05 mL) and 16 treated with IVT (4 mg/0.1 mL). The two groups were compared with regard to best-corrected visual acuity (BCVA), central macular thickness (CMT) on optical coherence tomography (OCT), slit-lamp biomicroscopy and fundus fluorescein angiography results, intraocular pressure (IOP), numbers of injections, and adverse events.

RESULTS

The mean follow-up times in the IVB and IVT groups were 17.45±8.1 months (range: 8-33 months) and 19.94±10.59 months (range: 6-40 months), respectively (P = 0.431). Visual acuity increased and CMT decreased significantly within both groups, but no differences were observed between the groups (P = 0.718). The percentages of patients with increased IOP and iatrogenic cataracts were significantly higher in the IVT group than in the IVB group.

CONCLUSIONS

Treatment with IVB and IVT both resulted in significant improvement in visual acuity and a decrease in CMT in patients with ME secondary to non-ischemic CRVO, with no difference between the two treatments. The incidence of adverse events, however, was significantly greater in the IVT group than in the IVB group. IVB may be preferred over IVT for the treatment of ME in patients with non-ischemic CRVO.

Noninfectious endophthalmitis occurring after intravitreal triesence injection

PURPOSE

To report a case of noninfectious endophthalmitis occurring after intravitreal Triesence (preservative-free triamcinolone acetonide) injection.

METHOD

Case report.

RESULTS

A 62-year-old patient with macular edema occurring after cataract surgery received 0.1 mL (4 mg) of intravitreal Triesence to the left eye. His vision was 20/60. One day later, he presented with a decrease in vision to light perception upon awakening. He denied ocular pain, and the eye was not red. Clinical examination was remarkable for orbital proptosis, minimal fibrin on the anterior chamber intraocular lens, and a white hypopyon. There was no view of the retina due to vitreous opacities. A vitreous tap and injection of intravitreal Ceftazidime and Vancomycin were performed. Microbiology showed no organisms on gram stain, and the cultures were negative. The endophthalmitis resolved, and the patient recovered vision to 20/70.

CONCLUSIONS

Noninfectious endophthalmitis can occur after preservative-free commercially available intravitreal Triesence. This case suggests that noninfectious endophthalmitis can occur in the absence of the benzyl alcohol found in preserved preparations of Kenalog.

Incidence of noninfectious endophthalmitis after intravitreal injection of preservative-free triamcinolone acetonide

PURPOSE

To determine the incidence of noninfectious inflammatory endophthalmitis after preservative-free intravitreal triamcinolone acetonide (PF-IVTA) injection.

PATIENTS AND METHODS

We performed a retrospective interventional case series, reviewing the medical records of all patients receiving PF-IVTA injection from July 1, 2006, through December 31, 2006; 444 patients were identified who received a total of 502 PF-IVTA injections. Demographic information and details of postinjection inflammation or endophthalmitis were collected.

RESULTS

Eleven eyes (2.2%) of 11 patients (2.5%) had an inflammatory reaction after PF-IVTA injection. Complete obscuration of all fundus details was observed in seven eyes, while moderate inflammation was noted in four eyes. An inflammatory hypopyon, thought not to represent particles of triamcinolone, was seen in eight eyes. The indication for IVTA injection was cystoid macular edema in seven eyes.

CONCLUSIONS

Postinjection inflammatory reactions are not uncommon after PF-IVTA injection. Noninfectious endophthalmitis after IVTA injection appears to be more common in eyes being treated for cystoid macular edema.

Drug-induced uveitis

INTRODUCTION

Drug-induced uveitis is a well described but often overlooked and/or misdiagnosed adverse reaction to medication. There are an increasing number of medications that have been related to the onset of intraocular inflammation. Identification of these inciting agents may decisively help the diagnostic algorithm involving new cases of uveitis.

AREAS COVERED

This review intends to be an updated comprehensive, practical guide for practitioners regarding the main drugs that have been associated with uveitis. A classification proposed by Naranjo et al. in 1981 for establishing potential causality is applied examining possible mechanisms of action. A guide for clinicians about the rationale of these observations when dealing with patients with uveitis is provided.

EXPERT OPINION

Several agents with different routes of administration (systemic, topical and/or intraocular) may cause intraocular inflammation. The mechanism behind ocular inflammation is frequently unknown. Clinicians should be aware of the potential drug effect to optimize diagnosis and management of such patients.

Noninfectious inflammation after intravitreal injection of aflibercept: clinical characteristics and visual outcomes

PURPOSE

To report the presenting features and clinical outcomes of a series of patients with noninfectious inflammation after intravitreal aflibercept injection.

DESIGN

Noncomparative consecutive case series.

METHODS

Medical records of patients who presented with noninfectious inflammation after intravitreal aflibercept injection between November 18, 2011 and June 30, 2013 were retrospectively reviewed.

RESULTS

A total of 20 cases of postinjection inflammation were identified in 5356 aflibercept injections. The patients presented 1-13 days after aflibercept injection (median 3 days); all noted decreased vision, while 3 of 20 (15%) had pain and 2 of 20 (10%) had conjunctival injection. One patient had a hypopyon (0.5 mm), and the average anterior chamber cell was 1.8+ (range 0 to 4+). All eyes had some degree of vitritis (average 1.8+; range 0.5+ to 4+). Patients on average had received 6 prior aflibercept injections (range 0-16). Only 1 patient-the first to present with inflammation in this series-received an intravitreal tap (culture negative) and injection of antibiotics. All patients were managed with frequent topical steroids and were followed closely for signs of improvement. All but 1 patient regained their preinjection visual acuity (average: 33 days; range: 7-73 days). Four patients were subsequently rechallenged with aflibercept, and 1 developed inflammation again after 5 additional aflibercept injections. The overall incidence of inflammation after intravitreal aflibercept injection was 20 of 5356 injections (0.37%) or 19 of 844 patients (2.25%). However, a disproportionate number of cases clustered around 1 provider (17/20, 85%; P < .001 vs all other providers) and around the 2 office locations where this physician primarily worked (16/20, 75%; P < .001 vs 5 other offices).

CONCLUSIONS

Noninfectious inflammation after intravitreal aflibercept injection typically presents without pain, conjunctival injection, or hypopyon, and responds to topical steroid therapy. The visual outcomes are generally favorable, though the return to baseline acuity can take many weeks.

Intravitreal pharmacokinetics after posterior subtenon triamcinolone acetonide injection in vitrectomized rabbit eyes

PURPOSE

To investigate the intraocular pharmacokinetics of triamcinolone acetonide (TA) injected into the posterior subtenon of vitrectomized rabbit eyes.

METHODS

Vitrectomy was performed on the right eyes of 35 rabbits. Triamcinolone acetonide (40 mg/mL) was injected into the posterior subtenon space of both eyes. Five rabbits each were killed at days 1, 3, 7, 14, 28, 56, and 84. Both eyes were enucleated. The vitreous was isolated, and TA concentration was measured.

RESULTS

In vitrectomized eyes, the intravitreal concentrations of TA were 1763, 822.9, 321.5, 113.3, 35.5, 14.4, and 6.7 ng/mL, respectively, at the time points indicated above; the concentrations in nonvitrectomized eyes were 397.8, 360.4, 154.4, 48.5, 30.7, 15.2, and 8.0 ng/mL, respectively. Triamcinolone acetonide concentrations were significantly higher in the vitrectomized eyes at days 1, 3, 7, and 14. The terminal half-life of intravitreal TA was 23.3 days in the vitrectomized eyes and 28.9 days in the nonvitrectomized eyes.

CONCLUSION

Intravitreal absorption and excretion of TA in the posterior subtenon space are increased after vitrectomy. Although the terminal half-life of TA was shorter, higher early concentration and similar effective duration were achieved in the vitrectomized eyes.

Prevention and treatment of injection-related endophthalmitis

BACKGROUND

Intravitreal injections are the fastest growing cause of endophthalmitis and can result in severe vision loss. The prevention, diagnosis and management of such infections remain unclear and at times controversial.

METHODS

We searched Pubmed for keywords "prophylaxis," "endophthalmitis," "intravitreal injection." We focused on studies published in the last 2 years as well as other recent studies with particular attention to data on the incidence, microbiology, prevention, and treatment of injection-related endophthalmitis.

RESULTS

Over 20 relevant studies were found. With povidone-iodine preparation, the per-injection endophthalmitis rate is low at about 0.03%. Antibiotics do not appear to be beneficial for prevention of post-injection endophthalmitis. The best timing of vitrectomy is unclear.

CONCLUSIONS

Antibiotic prophylaxis is probably not needed when giving intravitreal injections. More data is needed to help determine the proper treatment for post-injection endophthalmitis.

Long-term outcomes of triamcinolone acetonide-assisted anterior vitrectomy during complicated cataract surgery with vitreous loss

PURPOSE

To report the long-term outcomes of triamcinolone acetonide-assisted anterior vitrectomy during complicated cataract surgery with vitreous loss.

SETTING

Tel Aviv Medical Center, Tel Aviv, Israel.

DESIGN

Case series.

METHODS

Consecutive patients who had triamcinolone acetonide-assisted anterior vitrectomy for complicated cataract surgery with vitreous loss between January 2010 and January 2012 were studied. The main outcome measures were the results of the ocular examination and spectral-domain optical coherence tomography of the macula at the last follow-up visit 12 months or more postoperatively. The ocular examination included corrected distance visual acuity (CDVA), intraocular pressure (IOP), and anterior segment and fundus biomicroscopy.

RESULTS

The study included 15 patients (15 eyes) with a mean age of 71 years (range 50 to 92 years). The mean follow-up was 21 months (range 12 to 29 months). At the last follow-up, the mean CDVA was statistically significantly better than preoperatively (0.24 logMAR ± 0.31 [SD] versus 0.89 ± 0.81 logMAR) (P=.0033); all patients had improved CDVA over the preoperative values. Except for 1 patient with a macular scar, all the patients had a CDVA between 20/40 and 20/20. At last follow-up, 1 patient required 2 IOP-lowering medications that had been used preoperatively as well. The mean IOP was 15.3 ± 2.4 mm Hg. There were no cases of residual vitreous strands in the anterior chamber, inflammatory reactions, triamcinolone acetonide crystals, retinal breaks, retinal detachment, or pseudophakic cystoid macular edema.

CONCLUSION

Triamcinolone acetonide-assisted anterior vitrectomy during complicated cataract surgery with vitreous loss was safe and effective.

Chromovitrectomy: update

The basic concept for the application of vital dyes during vitreoretinal surgery is to assist in highlighting preretinal membranes and tissues which are very thin and semitransparent and thus difficult to detect. The vital dyes may be classified according to different criteria, where the most commonly applied includes chemical classification. In ophthalmic surgery, vital dyes are widely used in cataract and vitreoretinal surgery. The vital dyes, indocyanine green, infracyanine green, and brilliant blue stain the internal limiting membrane, and trypan blue and triamcinolone acetonide help to visualize epiretinal membranes and vitreous, respectively. This review exhibits the current literature regarding the properties of vital dyes, techniques of application, indications, and toxicities during vitreoretinal surgery and, also suggests that the field of chromovitrectomy represents an expanding area of research.

Povidone-iodine contact time and lid speculum use during intravitreal injection

PURPOSE

To determine the time necessary for 5% povidone-iodine (PI) to cause a significant reduction in colony-forming units and whether a lid speculum increases the conjunctival flora.

METHODS

This was a prospective randomized study of 131 eyes undergoing intravitreal injection. Conjunctival samples were collected in a prospective protocol at three points before intravitreal injection: (1) no intervention (baseline), (2) after placement of a lid speculum, and (3) after treatment with 5% PI. Participants were randomized into three different PI exposure intervals. Cultures were incubated for 6 days, and the resulting colony-forming units were tallied for each intervention.

RESULTS

Use of 5% PI caused significant decrease in the number of colony-forming units (P < 0.0001). Exposure to PI for 15 seconds did not cause a significant reduction in conjunctival bacteria (P = 0.08), but a significant reduction was observed after 30 seconds of exposure and beyond (P = 0.0003). Placement of a lid speculum did not result in a significant increase or decrease in the number of colony-forming units when compared with baseline (P = 0.47).

CONCLUSION

The use of 5% PI causes a significant reduction in bacterial colonies, and 30 seconds of exposure appears to be an adequate time to decrease conjunctival bacterial counts. Lid speculum use before intravitreal injection does not affect the overall conjunctival flora.