Optic nerve head diurnal vessel density variations in glaucoma and ocular hypertension measured by optical coherence tomography angiography.

BACKGROUND/AIMS: To evaluate diurnal variations in optic nerve head (ONH) vessel density assessed by optical coherence tomography angiography (OCT-A) in healthy subjects, ocular hypertension (OHT), and open-angle glaucoma (OAG) patients. METHODS: Forty subjects (OAG, 21; OHT, 6; healthy, 13) were assessed for vessel density percentage (VD%) and flow index in the ONH (NH VD%, NH index), and in the radial peripapillary capillary layer (RPC VD%, RPC index) at 9:00, 11:00, 14:00, 16:00, and 18:00 on a single day. Repeated measures ANOVAs were used to test for changes in the parameters measured at multiple time points. RESULTS: All OCT-A parameters analyzed at the different time points were statistically lower in the OAG patients compared to both the OHT and healthy groups (p < 0.05). In the OAG group, the NH index, RPC index, NH VD%, and RPC VD% were statistically lower at 18:00 compared to 14:00, and the RPC VD% was statistically lower at 9:00 than 14:00. In the OHT group, the RPC index was statistically lower at 9:00 than 11:00. In the healthy group, the NH VD% and RPC VD% were statistically lower at 16:00 than 18:00, and the RPC index was statistically lower at 9:00 than 11:00. No other statistically significant difference was found in none of the three groups comparing any other time point (p > 0.05). CONCLUSION: In healthy subjects, OHT and OAG patients, the variations in the OCT-A derived parameters were relatively small. These results suggest that in the clinical practice the OCT-A assessment can be performed independently of the time of the day, contrasting IOP evaluation.

Morpho-functional survey in children suspected of inherited retinal dystrophies via video recording, electrophysiology and genetic analysis.

PURPOSE: To present a detailed study matching functional response and video imaging with genetic analysis in children suspected of inherited retinal dystrophy (IRD). METHODS: Sixteen children underwent fundus examination via video recording (Heine Omega 500 indirect ophthalmoscope with DV1 camera) and electroretinogram (ERG) under general anesthesia to investigate the cause of suspected low vision. The patients [median age 12 (interquartile range 8-57.5) months] had associated genetic analysis performed with next-generation sequencing or array-comparative genomic hybridization. RESULTS: Four children had potential pathogenic variants in genes involved in Leber congenital amaurosis and Joubert syndrome (NMNAT1, CEP290, KCNJ13, IMPDH1); 1 child had a 16p11.2 microdeletion and 1 in 2q22.1. The ERG was altered in 6 patients, fundus imaging showed serious abnormality matching an IRD in 7 children, and less severe fundus alterations were found in 2 subjects. CONCLUSION: Fundus imaging associated with ERG may be significant in IRD diagnosis and visual impairment prognosis, alongside genetic analysis and therapy in selected cases.

Evaluating the effect of pupil dilation on spectral-domain optical coherence tomography measurements and their quality score.

BACKGROUND: Spectral-domain optical coherence tomography (SD-OCT) provides fast scan speed and high scan resolution improving its diagnostic accuracy. The purpose of this study was to evaluate if SD-OCT measurements and their quality score are influenced by pupil dilation. METHODS: Retinal nerve fiber layer thickness (RNFL), ganglion cell complex (GCC) and optic nerve head (ONH) were measured in one eye of 57 glaucoma patients and 36 healthy subjects using spectral domain optical coherence tomography (SD-OCT) before and after pupil dilation. Comparisons were made between measurements and their quality score pre- and post dilation (Signal Strength Index, SSI). Overall RNFL, average GCC and ONH rim volume were considered in the analysis. RESULTS: No statistically significant differences were found between pre- and post-dilation measurements in both groups (glaucoma: RNFL 80 ± 15 µm vs 80 ± 16 µm, p = 0.87; GCC 81.35 ± 13.4 µm vs 81.10 ± 13.14 µm, p = 0.92; ONH 0.05 ± 0.11 mm(3) vs 0.04 ± 0.07 mm(3), p = 0.74; controls RNFL 99 ± 12 µm vs 98 ± 14 µm, p = 0.70; GCC 92.12 ± 6.7 µm vs 91.54 ± 7.05 µm, p = 0.72; ONH 0.11 ± 0.1 mm(3) vs 0.04 ± 0.07 mm(3), p = 0.36) nor between pre- and post-dilation quality score (glaucoma SSI RNFL 54.3 ± 10.3 vs 51.7 ± 18.1, p = 0.12; SSI GCC 58 ± 9.5 vs 57 ± 8.09, p = 0.55; SSI ONH 48.5 ± 7.6 vs 46.6 ± 7.2, p = 0.16; controls SSI RNFL 57 ± 10.3 vs 54 ± 9.31, p = 0.2; SSI GCC 60.9 ± 8.1 vs 58.8 ± 7.3, p = 0.3; SSI ONH 51.5 ± 8.9 vs 50.4 ± 8.3, p = 0.59). CONCLUSION: Pupil dilation doesn't affect SD-OCT measurements and their quality score.

Cytidine 5'-Diphosphocholine (Citicoline) in Glaucoma: Rationale of Its Use, Current Evidence and Future Perspectives.

Cytidine 5'-diphosphocholine or citicoline is an endogenous compound that acts in the biosynthetic pathway of phospholipids of cell membranes, particularly phosphatidylcholine, and it is able to increase neurotrasmitters levels in the central nervous system. Citicoline has shown positive effects in Parkinson's disease and Alzheimer's disease, as well as in amblyopia. Glaucoma is a neurodegenerative disease currently considered a disease involving ocular and visual brain structures. Neuroprotection has been proposed as a valid therapeutic option for those patients progressing despite a well-controlled intraocular pressure, the main risk factor for the progression of the disease. The aim of this review is to critically summarize the current evidence about the effect of citicoline in glaucoma.

Elevated intraocular pressure in patients with acromegaly.

PURPOSE: To evaluate central corneal thickness (CCT) and intraocular pressure (IOP) in a cohort of acromegalic patients, and to correlate CCT with serum levels of growth hormone (GH) and insulin-like growth factor 1 (IGF-1). METHODS: Consecutive patients affected by acromegaly underwent a comprehensive endocrinological and ophthalmological evaluation, including serum GH and IGF-1 levels, CCT measured with ultrasonic pachymetry and IOP assessed with Goldmann applanation tonometry. RESULTS: Fourteen patients with acromegaly and 28 healthy controls were included in the study. Acromegalic patients had a statistically higher median CCT (570 µm [range 551.5-638] vs 542.7 µm [range 461.5-610]; p < 0.01) and higher median IOP (17.2 mm Hg [range 14-21] vs 13.7 mm Hg [range 10.5-19]; p < 0.01) than healthy controls. No statistically significant correlation was found among CCT and GH, CCT and IGF-1, IOP and GH, IOP and IGF-1 in the acromegalic group, whereas a statistically significant correlation was documented between CCT and IOP in the entire cohort (Spearman's correlation coefficient: 0.56, p < 0.01). However, when IOP was corrected for CCT no significant difference was found between the two study groups (p = 0.07). CONCLUSIONS: Our results suggest that acromegaly is associated with an increased CCT, which could lead to an overestimation of IOP readings as determined with Goldmann applanation tonometry.

Common sequence variants in the LOXL1 gene in pigment dispersion syndrome and pigmentary glaucoma.

BACKGROUND: Single nucleotide polymorphisms (SNPs) within the LOXL1 gene are associated with pseudoesfoliation syndrome and pseudoesfoliation glaucoma. The aim of our study is to investigate a potential involvement of LOXL1 gene in the pathogenesis of pigment dispersion syndrome (PDS) and pigmentary glaucoma (PG). METHODS: A cohort of Caucasian origin of 84 unrelated and clinically well-characterised patients with PDS/PG and 200 control subjects were included in the study. Genomic DNA from whole blood was extracted and the coding and regulatory regions of LOXL1 gene were risequenced in both patients and controls to identify unknown sequence variations. Genotype and haplotype analysis were performed with UNPHASED software. The expression levels of LOXL1 were determined on c-DNA from peripheral blood lymphocytes by quantitative real-time RT-PCR. RESULTS: A significant allele association was detected for SNP rs2304722 within the fifth intron of LOXL1 (Odds ratio (OR = 2.43, p-value = 3,05e-2). Haplotype analysis revealed the existence of risk and protective haplotypes associated with PG-PDS (OR = 3.35; p-value = 1.00e-5 and OR = 3.35; p-value = 1.00e-4, respectively). Expression analysis suggests that associated haplotypes can regulate the expression level LOXL1. CONCLUSIONS: Haplotypes of LOXL1 are associated with PG-PDS independently from rs1048661, leading to a differential expression of the transcript.

Adherence and Persistence to Medical Therapy in Glaucoma: An Overview.

Glaucoma is a group of progressive optic neuropathies characterized by loss of retinal ganglion cells and visual field deterioration. Despite the fact that the underlying pathophysiology of glaucoma remains unknown, elevated intraocular pressure (IOP) is a well-established risk factor, and the only factor that can be modified. Robust evidence from epidemiological studies and clinical trials has clearly demonstrated the benefits of IOP control in reducing the risk of glaucoma progression. IOP-lowering therapy by the means of eye drops remains a first-line treatment option. However, like other chronic and asymptomatic conditions, many patients with glaucoma have difficulties in maintaining high rates of adherence persistence to prescribed medications. On average, patients with chronic medical conditions take 30-70% of the prescribed medication doses, and on average 50% discontinue medications in the first months of therapy. The ophthalmic literature shows similarly low rates of adherence to treatment. Indeed, poor adherence is associated with disease progression and increased complication rates, as well as healthcare costs. The present review analyzes and discusses the causes of variability of the adherence to the prescribed drugs. The education of patients about glaucoma and the potential consequences of insufficient adherence and persistence seems fundamental to maximize the probability of treatment success and therefore prevent visual disability to avoid unnecessary healthcare costs.

Risk factors associated with progression in exfoliative glaucoma patients.

PURPOSE: To evaluate exfoliative glaucoma (XFG) patients over 5 years, determining risk factors associated with progression or non-progression of glaucoma. METHODS: A retrospective, observational study. Patients were chosen from consecutive charts and data collected from each available visit included in the follow-up period. Data were abstracted for non-progressed XFG patients for 5 years and for progressed patients until glaucoma worsened. Progression was determined from patient records and by disc photographs. RESULTS: There were 71 (53%) progressed and 63 (47%) non-progressed XFG patients.Baseline parameters demonstrated worse visual field damage (p=0.014) and more prescribed medicines (p=0.03) in progressed patients. The mean intraocular pressure (IOP) for progressed patients was 18.7±4.3 and 17.3±3.4 mm Hg for non-progressed patients (p=0.047). The mean IOP that best separated the groups was 17 mm Hg with 60% staying non-progressed at or below this level and 30% above this level. At the last visit, progressed patients had more medicines prescribed (1.7) than non-progressed patients (1.3, p=0.005). A multivariate regression analysis showed higher mean, peak and variance of IOP, number of glaucoma medications at the final visit and presence of a disc hemorrhage (n=5) as independent risk factors for progression (p≤0.05). CONCLUSION: IOP reduction in XFG may be essential in reducing disease progression. The presence of disc hemorrhage in XFG may suggest an increased probability of progression despite treatment to within the normal IOP range.

Human recombinant nerve growth factor (Cenegermin) in a patient affected by primary congenital glaucoma with neurotrophic keratopathy.

PURPOSE: To report a case of neurotrophic keratopathy (NK) in a patient affected by primary congenital glaucoma (PCG) who undergone glaucoma drainage implant surgery. NK was successfully treated with human recombinant Nerve Growth Factor (Cenegermin) eye drops. CASE REPORT DESCRIPTION: A 46-years-old patient affected by primary congenital glaucoma underwent Ahmed glaucoma valve implantation in the right eye, after several unsuccessful surgeries to control intraocular pressure (IOP) since the age of three. Surgical intervention was performed without complications, and IOP was well-controlled post-operatively. However, 1 month after surgery, he developed NK with stromal ulceration, initially treated with a topical combination of preservative-free artificial tears and antibiotic ointment. As NK did not resolve, a new treatment with Cenegermin 20 µg/ml eye drops, 6 times daily, was started. OUTCOME: NK completely resolved after 8 weeks of Cenegermin treatment, with complete restoration of corneal integrity and improvement of corneal sensitivity and transparency. Visual acuity in the operated eye reverted to the pre-operative value. CONCLUSION: Cenegermin was extremely effective in restoring corneal integrity in this PCG patient with NK.

A new look at the safety and tolerability of prostaglandin analogue eyedrops in glaucoma and ocular hypertension.

INTRODUCTION: In the last 25 years, topical prostaglandin analogues (PGAs) have emerged to become first line and first choice therapeutic options in the management of glaucoma and ocular hypertension (OHT). Although the short-term efficacy and safety of PGAs has been extensively investigated, less is known about their long term safety and tolerability. This gap in current knowledge is clinically relevant, because treatment-related adverse events and long-term tolerability issues are key determinants of the overall success of long-term therapy and the final outcome of a lifelong, symptomless disease like glaucoma. AREAS COVERED: We include selected evidence pertaining to the safety and tolerability of available and emerging PGA formulations. We also outline PGA formulations with different concentrations of the active ingredient, different preservatives, and preservative-free (PF) options. EXPERT OPINION: Undoubtedly PGAs will continue to play a major role in the medical therapy of glaucoma and OHT. Despite extensive literature and prolonged clinical experience with these agents worldwide, a number of areas that warrant further research have been identified in the present review. Recently launched novel PGAs, or those still in development offer new opportunities and future challenges.

Evaluation of macular and optic nerve head parameters in amblyopic eyes: An optical coherence tomography study.

PURPOSE: To evaluate morphological differences in retinal nerve fibers layers (RNFL), optic nerve head (ONH), ganglion cell complex (GCC), and macular thickness between amblyopic and normal eyes from spectral domain optical coherence tomography (SD-OCT). METHODS: Of 234 eyes of 117 children, four groups emerged: group A (162 eyes of 81 non-amblyopic subjects); group B (32 fellow eyes of 32 subjects with monolateral amblyopia); group C (32 amblyopic eyes of 32 subjects affected by monolateral amblyopia); group D (8 amblyopic eyes of 4 subjects with bilateral amblyopia). Patients underwent SD-OCT for ONH parameters, RNFL, GCC and macular thickness, retina map, and ONH scan quality index (SQI). Two-sided p values <0.05 were taken as statistically significant. (Analysis: STATA v.13). RESULTS: Parameters with a significant difference between groups (p < 0.005) with their Standard Deviation (SD) are presented: rim area, 2.08 (0.49) mm2 in group A and 1.76 (0.68) mm2 in group C; disk area, 2.43 (0.45) mm2 in group A and 2.02 (0.71) mm2 in group C; central macular thickness, 250.99 (19.74) µm in group A and 267.16 (23.52) µm in group C; nerve fiber ONH SQI, 62.82 (13.15) in group A, 51.26 (15.55) in group C, 48.29 (14.37) in group D; retina map SQI, 63.34 (10.34) in group A and 57.34 (9.84) in group C. For other parameters no significant difference was observed (p > 0.005). CONCLUSIONS: Amblyopia may influence optic nerve morphology, central macular thickness, and OCT scan quality. RNFL and GCC are not affected by monolateral amblyopia.

Effect of COVID-19-related lockdown on ophthalmic practice in Italy: A report from 39 institutional centers.

BACKGROUND/OBJECTIVES: To compare the number of eye surgical procedures performed in Italy in the 2 months following the beginning of lockdown (study period) because of COVID-19 epidemic with those performed in the two earlier months of the same year (intra-year control) and in the period of 2019 corresponding to the lockdown (inter-year control). METHODS: Retrospective analysis of surgical procedures carried out at 39 Academic hospitals. A distinction was made between elective and urgent procedures. Intravitreal injections were also considered. Percentages for all surgical procedures and incidence rate ratios (IRR) for rhegmatogenous retinal detachment (RRD) events were calculated. A p value <0.05 was considered significant. RESULTS: A total of 20,886 versus 55,259 and 56,640 patients underwent surgery during the lockdown versus intra-and inter-year control periods, respectively. During the lockdown, only 70% of patients for whom an operation/intravitreal injection was recommended, finally underwent surgery; the remaining patients did not attend because afraid of getting infected at the hospital (23%), taking public transportation (6.5%), or unavailable swabs (0.5%). Elective surgeries were reduced by 96.2% and 96.4%, urgent surgeries by 49.7% and 50.2%, and intravitreal injections by 48.5% and 48.6% in the lockdown period in comparison to intra-year and inter-year control periods, respectively. IRRs for RRDs during lockdown dropped significantly in comparison with intra- and inter-year control periods (CI: 0.65-0.80 and 0.61-0.75, respectively, p < 0.001 for both). CONCLUSION: This study provides a quantitative analysis of the reduction of eye surgical procedures performed in Italy because of the COVID-19 epidemic.

Physiology-Enhanced Data Analytics to Evaluate the Effect of Altitude on Intraocular Pressure and Ocular Hemodynamics.

Altitude affects intraocular pressure (IOP); however, the underlying mechanisms involved and its relationship with ocular hemodynamics remain unknown. Herein, a validated mathematical modeling approach was used for a physiology-enhanced (pe-) analysis of the Mont Blanc study (MBS), estimating the effects of altitude on IOP, blood pressure (BP), and retinal hemodynamics. In the MBS, IOP and BP were measured in 33 healthy volunteers at 77 and 3466 m above sea level. Pe-retinal hemodynamics analysis predicted a statistically significant increase (p < 0.001) in the model predicted blood flow and pressure within the retinal vasculature following increases in systemic BP with altitude measured in the MBS. Decreased IOP with altitude led to a non-monotonic behavior of the model predicted retinal vascular resistances, with significant decreases in the resistance of the central retinal artery (p < 0.001) and retinal venules (p = 0.003) and a non-significant increase in the resistance in the central retinal vein (p = 0.253). Pe-aqueous humor analysis showed that a decrease in osmotic pressure difference (OPD) may underlie the difference in IOP measured at different altitudes in the MBS. Our analysis suggests that venules bear the significant portion of the IOP pressure load within the ocular vasculature, and that OPD plays an important role in regulating IOP with changes in altitude.

RPE65-Associated Retinopathies in the Italian Population: A Longitudinal Natural History Study.

Purpose: To investigate the course of inherited retinal degenerations (IRD) due to mutations in the RPE65 gene. Methods: This longitudinal multicentric retrospective chart-review study was designed to collect best corrected visual acuity (BCVA), Goldman visual field, optical coherence tomography (OCT), and electroretinography (ERG) measurements. The data, including imaging, were collected using an electronic clinical research form and were reviewed at a single center to improve consistency. Results: From an overall cohort of 60 Italian patients with RPE65-associated IRD, 43 patients (mean age, 27.8 ± 19.7 years) were included and showed a mean BCVA of 2.0 ± 1.0 logMAR. Time-to-event analysis revealed a median age of 33.8 years and 41.4 years to reach low vision and blindness based on BCVA, respectively. ERG (available for 34 patients) showed undetectable responses in most patients (26; 76.5%). OCT (available for 31 patients) revealed epiretinal membranes in five patients (16.1%). Central foveal thickness significantly decreased with age at a mean annual rate of -0.6%/y (P = 0.044). We identified 43 different variants in the RPE65 gene in the entire cohort. Nine variants were novel. Finally, to assess genotype-phenotype correlations, patients were stratified according to the number of RPE65 loss-of-function (LoF) alleles. Patients without LoF variants showed significantly (P < 0.05) better BCVA compared to patients with one or two LoF alleles. Conclusions: We described the natural course of RPE65-associated IRD in an Italian cohort showing for the first time a specific genotype-phenotype association. Our findings can contribute to a better management of RPE65-associated IRD patients.

A rare case of endophthalmitis after bleb needle revision for glaucoma Xen® gel stent.

PURPOSE: To describe the first case of endophthalmitis caused by Sphingobacterium spiritivorum, a glucose non-fermenting Gram-negative rod, in a patient previously implanted with a Xen® gel stent. CASE REPORT DESCRIPTION: An 83-year-old patient, affected by open-angle glaucoma and with a previous surgery of combined cataract extraction and Xen gel stent implantation, developed endophthalmitis 1 month after bleb needle revision with 5-fluorouracil injection. At presentation, best corrected visual acuity was hand movement, hypopyon was evident into the anterior chamber and a flat bleb with no sign of leakage was present over the Xen gel implant. OUTCOME: Immediate pars plana vitrectomy was performed, with intravitreal antibiotic administration and silicon oil tamponade. S. spiritivorum was isolated from vitreous bacterial culture. According to the antibiogram, patient was treated with topical fortified ceftazidime eyedrops and appropriate systemic antibiotics (intravenous meropenem, 500 mg every 8 h for 7 days, followed by oral cotrimoxazole, 160 + 800 mg, twice a day for 10 days). After 2 weeks of treatment, ocular inflammation was resolved, best corrected visual acuity was 0.1 (Snellen chart) and intraocular pressure was 18 mm Hg without topical hypotensive therapy. CONCLUSION: S. spiritivorum was isolated for the first time as a causative agent of endophthalmitis in humans. Bleb needle revision in patients with Xen gel implant is not free of complications, and an attentive follow-up is required.

Efficacy and Safety of PreserFlo® MicroShunt After a Failed Trabeculectomy in Eyes with Primary Open-Angle Glaucoma: A Retrospective Study.

INTRODUCTION: To evaluate the efficacy and safety of PreserFlo® MicroShunt in primary open angle glaucoma (POAG) eyes after a single failed trabeculectomy. METHODS: Retrospective review of POAG eyes with a failed trabeculectomy that underwent PreserFlo® MicroShunt implantation from March 2019 to November 2019, in two Italian glaucoma centers. Pre- and postoperative data were collected and compared. RESULTS: A total of 31 surgeries in 31 patients were reviewed. Mean preoperative IOP and mean preoperative number of medications were 24.12 ± 3.14 mmHg and 3.29 ± 0.64, respectively, and decreased to 12.56 ± 2.64 mmHg and 0.46 ± 0.77 at the 12-month postoperative follow-up visit (p < 0.01). The most frequent adverse events were transient hypotony (6 eyes, 19.3%) and choroidal effusion (3 eyes, 9.6%). In all cases spontaneous resolution was observed, with no intervention. CONCLUSION: In POAG eyes with a single failed trabeculectomy, the PreserFlo® MicroShunt was safe and effective in reducing the IOP after a 12-month follow-up. The PreserFlo® MicroShunt may represent a viable choice as a second surgery.

A Comparison of Hyper-Reflective Retinal Spot Counts in Optical Coherence Tomography Images from Glaucomatous and Healthy Eyes.

PURPOSE: To compare the number of hyper-reflective retinal spots (HRS) in optical coherence tomography (OCT) images of healthy controls and patients affected with primary open angle glaucoma (POAG). METHODS: Thirty patients affected with POAG and 34 healthy controls were recruited and underwent raster OCT examination of the macular region. Among the acquired B-scans, the one with the lowest foveal thickness was selected, and a central area of 3000 µm was defined (region of interest, ROI), in order to identify HRS. HRS were defined as small point-like hyper-reflective elements, detectable at the visual inspection of the OCT image. HRS were independently counted by two investigators in the ROI of each OCT scan. RESULTS: Inter-rater agreement for HRS counting was good to excellent (ICC = 0.96, 95% CI: 0.83-0.99). More HRS were found in the OCT images from glaucoma patients, in comparison with healthy controls (average value: 90.5 ± 13.02 and 74.72 ± 11.35, for glaucoma and healthy subjects, respectively; p < 0.01). Significant correlations between the average number of HRS and visual field mean deviation (MD, p = 0.01) and pattern standard deviation (PSD, p < 0.01) were found. CONCLUSIONS: OCT images from glaucoma patients showed a higher number of HRS when compared with healthy controls. As HRS have been hypothesized to be a sign of neuroinflammation, these results may support the role of neuroinflammation in glaucoma etiopathogenesis.

Pre-operative conjunctival flora in patients with local and/or systemic risk factors for post cataract surgery infection in Northern Italy.

PURPOSE: To investigate the pre-operative conjunctival flora in patients undergoing cataract surgery with major local and/or systemic risk factors for developing post-operative infection. METHODS: A total of 83 patients underwent bacterial culture and sensitivity testing of conjunctival swabs obtained from both eyes because of local risk factors at the pre-operative visit (i.e. chronic blepharitis, conjunctivitis, or lacrimal system disease), and/or systemic risk factors (i.e. autoimmune or skin disorders) for developing post-operative infection. If the swab was found positive, an antimicrobial susceptibility test was performed, and a specific antibiotic therapy was administered. Surgery was performed when a repeat conjunctival swab (after antibiotic treatment) showed negative cultures. RESULTS: Cultures were found positive in 25.3% of patients. Staphylococcus aureus (18%) and Staphylococcus epidermidis (15%) were the most frequently isolated microorganisms. Gram-negative bacteria, including Pseudomonas aeruginosa, were present in nine cases (8%). CONCLUSION: Present results showed a low rate of swab positivity compared to previous published data, and slightly different microbial flora. The differences observed may be caused by geographical factors and/or to the specific characteristics of the subgroup of studied patients. Considering that the surface microbial flora is one of the major causes of endophthalmitis, this information may be useful in selecting antibacterial regimens to prevent serious ocular infections, and restrain the increasing problem of antibiotic resistance.