Development of Analytical Method for the Quantitation of Monoclonal Antibodies Solutions via Raman Spectroscopy: The Case of Bevacizumab.

Personalized dosages of monoclonal antibodies are being used more regularly to treat various diseases, rendering their quantitation more essential than ever for the right dose administration to the patients. A promising alternative, which overcomes the obstacles of the well-established chromatographic techniques regarding the quantification of biopharmaceuticals, is Raman spectroscopy. This study aimed to develop and validate a novel analytical method for the quantitation of bevacizumab in solutions via Raman spectroscopy. For this purpose, a droplet of the solution was left to dry on a highly reflective carrier and a home-made apparatus was employed for rotation of the sample. Hence, each recorded Raman spectrum was the average of the signal acquired simultaneously from multiple points on a circular circumference. The method was validated, and the detection limit of the antibody was found to be 1.06 mg/mL. Bevacizumab was found to be highly distributed at the formed coffee ring of the dried droplet, though this was a function of solution concentration. Finally, Raman spectra at different distances on the coffee ring were obtained from the four quarters. The lowest bevacizumab detection limit was found at a distance of 75 µm from the external side of the coffee ring and it was determined to be equal to 0.53 mg/mL.

Isolated optic neuritis after pembrolizumab administration for non-small-cell lung carcinoma.

PURPOSE: To report a case of isolated optic neuritis associated with pembrolizumab immunotherapy for metastatic non-small cell lung carcinoma. CASE PRESENTATION: A 76-year-old man, with a history of metastatic non-small cell lung carcinoma, presented with vision loss in his left eye for the past week. He had been treated with pembrolizumab for the underlying disease for 2 months. On presentation, best corrected visual acuity was 20/30 in the right eye and 20/200 in the left eye. Fundoscopy revealed optic nerve edema in the left eye. Visual fields examination in right eye revealed an enlarged blind spot and an extended defect in the inferior nasal quadrant. In the left eye a partial superior arcuate defect and an extended defect in the inferior hemisphere was observed. The mean deviation was -12.15 dB in the right eye and -13.70 dB in left eye. Pembrolizumab was withheld and corticosteroids were administered for a total of nine weeks, first intravenously and then slowly tapered orally, resulting in resolution of optic neuritis, restoration of visual acuity and in relative improvement in the visual field defects after 3 months. Calculated Naranjo Nomogram score was 7, indicating a 'highly probable' correlation. CONCLUSIONS: Optic neuritis is a relatively rare immune-related adverse event after exposure to checkpoint inhibitors cancer immunotherapy. Prompt discontinuation of the offending agent and early initiation of corticosteroid therapy is the mainstay of the treatment.

Acadesine suppresses TNF-α induced complement component 3 (C3), in retinal pigment epithelial (RPE) cells.

RATIONALE: Age-related macular degeneration (AMD) is the most prevalent form of irreversible blindness in the developed world. Aging, inflammation and complement dysregulation affecting the retinal pigment epithelium (RPE), are considered significant contributors in its pathogenesis and several evidences have linked tumor necrosis factor alpha (TNF-α) and complement component 3 (C3) with AMD. Acadesine, an analog of AMP and an AMP-activated protein kinase (AMPK) activator, has been shown to have cytoprotective effects in human clinical trials as well as having anti-inflammatory and anti-vascular exudative effects in animals. The purpose of this study was to evaluate if acadesine is able to suppress TNF-α induced C3 in RPE cells. METHODS: ARPE-19 and human primary RPE cells were cultured and allowed to grow to confluence. TNF-α was used for C3 induction in the presence or absence of acadesine. Small molecule inhibitors and siRNA were used to determine if acadesine exerts its effect via the extracellular or intracellular pathway and to evaluate the importance of AMPK for these effects. The expression level of C3 was determined by immunoblot analysis. RESULTS: Acadesine suppresses TNF-α induced C3 in a dose dependent manner. When we utilized the adenosine receptor inhibitor dipyridamole (DPY) along with acadesine, acadesine's effects were abolished, indicating the necessity of acadesine to enter the cell in order to exert it's action. However, pretreatment with 5-iodotubericidin (5-Iodo), an adenosine kinase (AK) inhibitor, didn't prevent acadesine from decreasing TNF-α induced C3 expression suggesting that acadesine does not exert its effect through AMP conversion and subsequent activation of AMPK. Consistent with this, knockdown of AMPK α catalytic subunit did not affect the inhibitory effect of acadesine on TNF-α upregulation of C3. CONCLUSIONS: Our results suggest that acadesine suppresses TNF-α induced C3, likely through an AMPK-independent pathway, and could have potential use in complement over activation diseases.

The Acute Effects of Electronic Cigarette Vaping and Tobacco Cigarette Smoking on Choroidal Thickness in Young, Healthy, Habitual, Dual Smokers.

The present study aims to evaluate and compare the acute effects of tobacco cigarettes (TC) smoking and electronic cigarette (EC) vaping on foveal and choroidal thickness (CT) in young, healthy, dual smokers. Participants underwent four trials: 5 min TC; 5 min EC; 30 min EC; and 60 min nothing (sham trial). Scans before and immediately after each trial were obtained using spectral domain optical coherence tomography with the enhanced depth imaging mode. Changes in central foveal thickness (CFT), subfoveal choroidal thickness (SFCT), and CT at fourother points, 500 µm and 1000 µm temporally and nasally to the fovea, were measured. Forty-seven participants (33 male, 14 female; mean age 24.85 ± 1.57 years) were included. They smoked 13.53 ± 5.27 TCs/day for 6 ± 2.3 years and vaped ECs for the past 2.4 ± 1.08 years. We did not observe any statistically significant change in SFCT, CFT, and CT of the other points after any of the fourtrials. The acute changes in CFT and CT after EC vaping or TC smoking did not differ significantly compared to the sham trial. Smoking and vaping does not seem to result in statistically significant acute alterations in foveal and CT in young, dual smokers.

Brinzolamide-brimonidine fixed combination for the prevention of intraocular pressure elevation after phacoemulsification.

AIM: To evaluate the effectiveness of brinzolamide-brimonidine fixed combination to control the intraocular pressure elevation throughout the first 24 h following uncomplicated phacoemulsification cataract surgery. PATIENTS AND METHODS: A total of 62 patients who underwent phacoemulsification cataract surgery were included in this prospective randomized comparative case series. The brinzolamide-brimonidine fixed combination group (34 eyes) was administered a single dose of brinzolamide-brimonidine fixed combination immediately after phacoemulsification. No treatment was administered in the control group (28 eyes). Intraocular pressure was measured 1 day before surgery (baseline) and at 6, 12 and 24 h postoperatively. RESULTS: The brinzolamide-brimonidine fixed combination group had significantly lower intraocular pressure at 6, 12 and 24 h after phacoemulsification compared to baseline (p < 0.0001 for all comparisons), while in control group, intraocular pressure was significantly higher at 6 and 12 h after surgery compared to baseline (p < 0.001 and p < 0.0001, respectively). In control group, an intraocular pressure elevation ⩾ 5 mm Hg was noted in 32.4% of the eyes at 6 and 12 h and in 5.9% of eyes at 24 h after surgery, while in brinzolamide-brimonidine fixed combination group, only 8.8% of the eyes at 6 h postoperatively had such an intraocular pressure elevation. CONCLUSION: The administration of a single drop of brinzolamide-brimonidine fixed combination effectively prevented intraocular pressure elevations and intraocular pressure spikes during the first 24 h after uneventful phacoemulsification.

Dexamethasone implant for immunogammopathy maculopathy associated with IgA multiple myeloma.

BACKGROUND: We describe a case where hyperviscosity retinopathy and immunogammopathy maculopathy were the presenting features of IgA multiple myeloma and report the response of maculopathy to intravitreal injection of dexamethasone implants. CASE PRESENTATION: A 56-year-old man presented at the Department of Ophthalmology with the chief complain of reduced vision for the past 10 days in both eyes. Ophthalmic examination revealed central retinal vein occlusion resembling signs with severe macular edema in both eyes with prominent serous macular detachment. After comprehensive evaluation, an IgA type kappa multiple myeloma was diagnosed complicated with hyperviscosity-associated retinopathy and immunogammopathy maculopathy. Patient was treated with multiple sessions of plasmapheresis, systemic chemotherapy, and finally intravitreal implants of dexamethasone with complete restoration of macular edema and serous macular detachment in both eyes. The visual function and the hyperviscosity-associated retinopathy were partially restored. CONCLUSION: Ocular manifestation might be the only presenting sign of a life-threatening disease such as IgA multiple myeloma. A high level of suspicion is required to diagnose and treat such cases promptly and effectively.

Analgesic Effect of a Single Drop of Nepafenac 0.3% on Pain Associated with Intravitreal Injections: A Randomized Clinical Trial.

PURPOSE: To evaluate the analgesic effect of nepafenac 0.3% in patients undergoing intravitreal injections (IVI) of antivascular endothelial growth factors. METHODS: This is a single-center, prospective, randomized, blinded, triple-arm, placebo-controlled interventional study. Patients were randomized into 3 Groups. Group 1 (n = 33) received nepafenac 0.1%, Group 2 (n = 32) received nepafenac 0.3%, and Group 3 (n = 31) received placebo 40 min before IVI. Using the short form of the McGill Pain Questionnaire (SF-MPQ), pain intensity was assessed with the visual analog scale (VAS), the Main Component of the SF-MPQ, and the present pain intensity (PPI) scores immediately and 6 h postinjection. RESULTS: Immediately after IVI, the VAS pain score was statistically significantly lower in patients treated with nepafenac 0.1% and 0.3%, compared with placebo (P < 0.001 and P = 0.001, respectively). The PPI scores were statistically significantly lower when nepafenac 0.1% or 0.3% was instilled compared with placebo (P = 0.01 and P < 0.0001, respectively). The Main Component of the SF-MPQ scores were statistically significantly lower after nepafenac 0.1% and 0.3% administration compared with placebo (P = 0.001 and P < 0.001, respectively). Six hours post-IVI the nepafenac 0.3% demonstrated statistically significantly higher analgesic effect compared with nepafenac 0.1% and placebo as this was indicated by the VAS pain score (P = 0.013 and P < 0.00001, respectively) and by the PPI score (P = 0.01 and P < 0.00001, respectively). CONCLUSIONS: A single instillation of nepafenac 0.1% or 0.3% before IVI could effectively alleviate the IVI-related pain. The 0.3% formula exerts its analgesic effect more intensively at 6 h after the IVI.

UVB-mediated down-regulation of proteasome in cultured human primary pterygium fibroblasts.

BACKGROUND: Pterygium is a condition characterized by epithelial overgrowth of the cornea, inflammatory cell infiltration and an abnormal extracellular matrix accumulation. Chronic UV exposure is considered as a pathogenic factor of this disease. Proteasome is an intracellular multi-subunit protease complex that degrades intracellular proteins. Among proteasome subunits the ß5 (PSMB5), bearing chymotrypsin-like activity. It is considered as the main proteasome subunit and its expression is mediated by Nrf2-ARE pathway in many cell types. This study investigates the expression of PSMB5 in pterygium and the effect of UVB irradiation on its expression and activity in pterygium fibroblasts. METHODS: Normal conjunctival and pterygium specimens were obtained from the bulbar conjunctiva of patients undergoing cataract surgery and from patients with pterygium undergoing surgical removal of primary tissue, respectively. Fibroblasts were isolated upon treatment of specimens with clostridium collagenase. The expression of PSMB5 and Nrf2 in tissues and cells was ascertained by RT-PCR analysis and western blotting. Cell survival was measured by the MTT method and the proteasome chymotrypsin-like activity was determined by fluorometry. RESULTS: RT-PCR analysis showed that the expression of PSMB5 was significantly lower in pterygium than in normal conjunctiva. The expression of PSMB5 was mediated by the Nrf2/ARE pathway as indicated by using the Nrf2 activator Oltipraz. The expression of PSMB5 and Nrf2 by pterygium fibroblasts was suppressed in a dose dependent manner following UVB radiation of 0-50 mJ/cm2 doses. The expression of PSMB5, but not of Nrf2, remained at almost the control levels, when UVB exposure was performed after pre-incubation of cells with the src kinases inhibitor PP2. UVB irradiation had very low deleterious effect on fibroblasts survival, while it did not affect the proteasome chymotrypsin-like activity. CONCLUSION: In pterygium fibroblasts, UVB exposure leads to down-regulation of Nrf2/ARE-mediated PSMB5 gene expression, in which src kinases may be implicated. This effect may be partially responsible for the lower expression of PSMB5 detected in pterygium as compared to normal conjunctiva.

Intravitreal aflibercept for choroidal neovascularization secondary to angioid streaks in a non-responder to intravitreal ranibizumab.

PURPOSE: To report the 12-month outcomes of a patient switching from intravitreal ranibizumab to aflibercept for choroidal neovascularization (CNV) associated with angioid streaks (AS). RESULTS: A 42-year-old Caucasian female with CNV associated with AS underwent intensive treatment with ranibizumab without significant functional or anatomic change. Treatment was then switched to aflibercept and the patient received the proposed age-related macular degeneration treatment regimen. After 3 loading doses of aflibercept, best-corrected visual acuity (BCVA) improved from 3/10 to 6/10, while optical coherence tomography (OCT) demonstrated resolution of the subretinal fluid with a reduction of the intraretinal fluid. After 12 months and 7 intravitreal injections of aflibercept, BCVA returned to 3/10, while OCT had demonstrated further morphologic improvement. CONCLUSION: Our case shows that aflibercept may be an alternative treatment for advanced cases of CNV associated with AS that respond insufficiently to ranibizumab injections. Prospective studies are required to further evaluate the effect of aflibercept and to propose a standardized treatment protocol for this entity.

Pattern dystrophies in patients treated with deferoxamine: report of two cases and review of the literature.

BACKGROUND: Deferoxamine (DFO) is one of the most commonly used chelation treatments for transfusional hemosiderosis. Pattern dystrophies constitute a distinct entity of retinal disorders that has been occasionally identified in association with deferoxamine. CASE PRESENTATION: We report two cases of bilateral macular pattern dystrophy in transfusion dependent patients undergoing chronic chelation therapy with deferoxamine due to thalassemias. Our patients were evaluated with multimodal imaging and the results are presented. Both patients had normal cone and rod responses in the full-field electroretinogram and continued the prescribed chelation therapy, after hematology consult. The patients were followed up every 3 months for 2 and 4 years respectively for possible deterioration. Their best corrected visual acuity remained stable with no anatomic change on Optical Coherence Tomography findings. CONCLUSION: Multimodal imaging of our patients allowed a better evaluation and possibly earlier detection of the DFO-related changes. Screening and close follow up of patients under chronic chelating therapy is important in order to promptly diagnose and manage possible toxicity either with discontinuation of the offending agent or dose modification.

An eye for azithromycin: review of the literature.

Azithromycin is used widely in clinical practice and recently it is available in topical solution for ophthalmic use. The purpose of the current publication is to summarize the newest information on azithromycin's clinical usefulness over ocular diseases. A PubMed (National Library of Medicine) and a ScienceDirect search was conducted using the key phrases 'azithromycin', 'meibomian', 'blepharitis', 'trachoma', 'toxoplasmosis' from 2010 to 2017. Articles were limited to articles published in English or at least having an English abstract. There were no restrictions on age, ethnicity, or geographic locations of patients. Topical azithromycin was found effective and safe in various ocular surface infections, in meibomian gland dysfunction and in trachoma. Also, it may substitute fluoroquinolones in corneal UV cross-linking. The World Health Organization targets for trachoma elimination are being reached only after 3 years of annual mass drug administration. Oral azithromycin can participate in combination regiments for toxoplasmosis, mainly because of its very good safety profile and may play a significant role in toxoplasmosis in pregnancy. Azithromycin is one of the safest antibiotics, well tolerated, and with special pharmacokinetic properties. Also, it is characterized by a broad antimicrobial spectrum. Azithromycin is efficacious for the treatment of a lot of ocular diseases and may be included as monotherapy or in combination therapy in new treatment protocols for more ocular infections. However, more research is needed to determine this.

Cystoid Macular Edema Due to Accidental Latanoprost Overdose After Uncomplicated Phacoemulsification.

OBJECTIVE: We present an interesting case of accidental overdose of latanoprost eye drops. CASE REPORT: A 71-year-old patient underwent an uncomplicated cataract surgery in his right eye. During the first postsurgical week he mistakenly used latanoprost eye drops six times daily instead of the prescribed tobramycin/dexamethasone eye drops. The patient experienced gradually decreasing visual acuity and was diagnosed with cystoid macular edema seven weeks after surgery. The cystoid macular edema resolved 4 weeks later after treatment with nepafenac 0.3% eye drops and oral acetazolamide. The cystoid macular edema recurred 2 weeks after rechallenge with latanoprost. The rechallenge-induced cystoid macular edema once again resolved after cessation of latanoprost and retreatment with nepafenac eye drops. A Naranjo assessment score of 7 was obtained, indicating a probable relationship between the patient's symptoms and the suspect drug.

Diclofenac for pain associated with intravitreal injections: a prospective, randomized, placebo-controlled study.

IMPORTANCE: Intravitreal injections (IVI) are often painful. BACKGROUND: To evaluate the analgesic effect of diclofenac in patients undergoing IVI. DESIGN: Single-centre, prospective, randomized, triple-arm, placebo-controlled, interventional study in the University Hospital of Patras. PARTICIPANTS: Seventy-four patients. METHODS: Group 1 (n = 25) received topical diclofenac 45 min before IVI, Group 2 (n = 25) received oral diclofenac 4 h before IVI and topical diclofenac while Group 3 (n = 24) received placebo before IVI. Using the short form of the McGill Pain Questionnaire (SF-MPQ), pain intensity was assessed with the visual analogue scale (VAS), the main component of the SF-MPQ and the Present Pain Intensity (PPI) scores immediately and 6 h post-IVI. MAIN OUTCOME MEASURES: The VAS pain score immediately post-IVI. RESULTS: Immediately post-IVI, patients in Group 2 reported significantly lower VAS pain scores compared to placebo while no statistically significant difference was found between patients that received topical diclofenac and placebo. Six hours post-IVI, patients in both treatment groups reported significant lower VAS pain scores compared to placebo. The scores of the main component of the SF-MPQ were significantly lower in patients of treatment groups compared to placebo at both time-points. Finally, while no statistically significant difference was found between the 3 Groups in PPI scores immediately post-IVI, 6 h later, patients of both treatment groups reported significantly lower PPI scores compared to placebo. CONCLUSIONS AND RELEVANCE: The combination of topical and oral diclofenac demonstrated better analgesic effect than topical diclofenac administration in patients undergoing IVI immediately and up to 6 h post-IVI.

Fibrinous Anterior Uveitis Following Topical Tetracaine Abuse.

BACKGROUND: A 54-year-old man presented complaining of severe pain and blurred vision in his left eye. Slit-lamp biomicroscopy revealed a large epithelial defect with an underlying prominent ring infiltrate and severe anterior uveitis with fibrinous exudates and hypopyon. Patient admitted abuse of topical tetracaine, which was discontinued and topical treatment with a non-steroidal antiinflammatory agent, an antibiotic, a cycloplegic agent were instituted while a therapeutic contact lens was applied. Response to treatment was favorable with a rapid resolution of anterior uveitis within days while the epithelial defect fully healed within a month. Four months later the patient returned with a new subtotal epithelial defect with no previous history of trauma or topical anesthetic abuse. CONCLUSION: In conclusion, while a common complication of topical tetracaine abuse is toxic keratopathy, we describe a case where tetracaine abuse was also complicated with a severe fibrinous anterior uveitis. Interestingly, in our case, anaesthetic abuse was complicated in the mid-term with a spontaneous corneal epithelial defect attributed to possible anaesthetic-induced anatomical changes, such as poor adhesion between the stroma and the epithelium.

Cystoid macular edema associated with preservative-free latanoprost after uncomplicated cataract surgery: case report and review of the literature.

BACKGROUND: Cystoid macular edema associated with latanoprost administration has been reported in patients after complicated cataract surgery with coexisting risk factors. We present the first case of preservative free latanoprost associated cystoid macular edema that occurred many months after uncomplicated cataract surgery. CASE PRESENTATION: A 65-year old Caucasian female presented in the Outpatients Clinic complaining of reduced vision and metamorphopsia in the right eye. She had undergone uneventful phacoemulsification 19 months ago in the right eye and was under treatment with preservative free latanoprost eye drops for the last 7 months for ocular hypertension. Her remaining medical and ocular history were otherwise unremarkable. Cystoid macular edema with serous retinal detachment was diagnosed in the right eye using optical coherence tomography and fluorescein angiography. Latanoprost was discontinued and brinzolamide and nepafenac eye drops were administered in the right eye. Two months later, cystoid macular edema completely resolved with restoration of visual acuity. Nepafenac eye drops were administered for another 2 months. Eight months after latanoprost cessation optical coherence demonstrated no sign of cystoid macular edema whereas a subtle epiretinal membrane was noted. CONCLUSIONS: Cystoid macular edema may potentially occur in patients receiving preservative free latanoprost. More interestingly, in our case it was diagnosed in a patient with a long standing pseudophakia after uncomplicated phacoemulsification. No obvious risk factor for macular edema development was recognized. Prompt diagnosis and latanoprost discontinuation resulted in complete resolution of the cystoid macular edema and functional restoration of the eye.

EFFECT OF BROMFENAC ON PAIN RELATED TO INTRAVITREAL INJECTIONS: A Randomized Crossover Study.

PURPOSE: To evaluate the analgesic effect of bromfenac, a topically administered nonsteroidal antiinflammatory agent, in patients undergoing intravitreal injections (IVIs) of anti-vascular endothelial growth factor agents. METHODS: A single center, prospective, randomized, double-blind, placebo-controlled, cross over interventional study. Patients scheduled to undergo IVI of anti-vascular endothelial growth factor were randomized to receive topical bromfenac or placebo before IVI. Pain perception was assessed using the short form of the McGill Pain Questionnaire. Pain intensity was evaluated with the visual analog scale, the main component of the short form of the McGill Pain Questionnaire, and the Present Pain Intensity scores immediately and 6 hours postinjection. RESULTS: Sixty-five patients (65 eyes) were enrolled in the study. Immediately after IVI, pain perception was statistically significant lower in patients treated with bromfenac compared with placebo as assessed by the visual analog scale pain score and the main component of the short form of the McGill Pain Questionnaire (P = 0.002 and 0.001, respectively). At 6 hours postIVI, pain was statistically significant lower in patients treated with bromfenac, according to the visual analog scale pain score, the main component of the short form of the McGill Pain Questionnaire, and the Present Pain Intensity score (P < 0.001, <0.001, and P = 0.001, respectively). Multivariable regression analysis revealed that pain perception, as evaluated with the visual analog scale pain score immediately after IVI, was significantly lower in patients of older age, female patients and those with higher number of previous injections. Immediately after IVI, bromfenac seemed to be more effective in younger patients and in those who had already undergone an amount of injections. CONCLUSION: Topical instillation of bromfenac significantly reduced the IVI-related pain immediately after and 6 hours postinjection.

Effect of Omega-3 Fatty Acids Dietary Supplementation on Ocular Surface and Tear Film in Diabetic Patients with Dry Eye.

OBJECTIVE: The objective of this study was to investigate the effect of dietary supplementation with omega-3 fatty acids on ocular surface and tear film in patients with type 2 diabetes suffering from dry eye. METHODS: Thirty-six patients suffering from type 2 diabetes and moderate to severe dry eye syndrome were included in the study. Patients were assigned to receive omega-3 long-chain polyunsaturated fatty acids for 3 months. Tear film break-up time test, Schirmer-I test, and conjunctival impression cytology analysis were performed on all patients at baseline and after 1 and 3 months. The subjective symptoms of dry eye were evaluated with the Ocular Surface Disease Index (OSDI) questionnaire at the same time points. RESULTS: Patients' average age was 65.57 ± 4.27 years and the mean duration of diabetes was 14.85 ± 5.4 years. There was a statistically significant increase in Schirmer-I test results and tear break-up time score after 3 months of supplementary intake of omega-3 fatty acids compared to baseline (p < 0.05 and p < 0.001, respectively). Impression cytology demonstrated a significantly lower grade of conjunctival squamous cell metaplasia after 1 and 3 months of omega-3 fatty acids intake compared to baseline (p < 0.05 and p < 0.01, respectively). The OSDI score was statistically significant lower both at 1 and 3 months after omega-3 fatty acids supplementation compared to baseline (p < 0.001). CONCLUSIONS: Omega-3 fatty acids may effectively improve tear film characteristics, reverse ocular surface features, and alleviate the subjective symptoms associated with dry eye syndrome in patients with type 2 diabetes.

Efficacy of Topical Ofloxacin 0.3 % Administration on Conjunctival Bacterial Flora in Diabetic Patients Undergoing Intravitreal Injections.

PURPOSE: This prospective, randomized case series study aims to evaluate the efficacy of ofloxacin 0.3% eye drops in eradication of conjunctival bacterial flora in diabetic patients undergoing intravitreal injections (IVI). METHODS: Ninety-two diabetic patients (92 eyes) scheduled to undergo intravitreal injection of ranibizumab due to diabetic macular edema were enrolled in the study. Patients were randomly assigned to three different groups. Group 1 (n=32) received ofloxacin eye drops the day before before IVI (four times); patients in Group 2 (n=29) were administered ofloxacin one hour before IVI (every 15 minutes), while Group 3 (n=31) comprised patients that received combined administration of ofloxacin both one day and one hour before IVI (eight doses). Samples were collected from the injection site before and after antibiotic administration. Culture results from BACTEC broth and positive cultures in blood agar and Sabouraud's dextrose agar plates were measured. RESULTS: In Group 1, BACTEC broth positive cultures decreased from 84.4% at baseline to 50% after ofloxacin administration (p=0.007), and blood agar positive cultures reduced from 65.63% to 34.38% (p=0.02). In Group 2, positive cultures significantly decreased in BACTEC broth (from 79.3% at baseline to 48.28%; p=0.027) and in blood agar (from 68.97% to 37.13%; p=0.034). In Group 3, positive cultures decreased from 77.42% at baseline to 32.26% (p=0.0008) and from 58.06% at baseline to 22.58% (p=0.009) in BACTEC broth and blood agar, respectively. No microorganisms were isolated from Sabouraud's dextrose agar plates. CONCLUSIONS: The combined one day/one hour (eight doses) ofloxacin administration in diabetic patients is extremely effective in reducing conjunctival bacterial flora. The application of topical ofloxacin for one day or one hour before IVI is also significantly effective.