Unraveling Azospirillum's colonization ability through microbiological and molecular evidence

It is known that members of the bacterial genus Azospirillum can promote the growth of a great variety of plants, an ability harnessed by the industry to create bioproducts aimed to enhance the yield of economically relevant crops. Its versatile metabolism allows this bacterium to adapt to numerous environments, from optimal to extreme or highly polluted. The fact of having been isolated from soil and rhizosphere samples collected worldwide and many other habitats proves its remarkable ubiquity. Azospirillum rhizospheric and endophytic lifestyles are governed by several mechanisms, leading to efficient niche colonization. These mechanisms include cell aggregation and biofilm formation, motility, chemotaxis, phytohormone and other signaling molecules production, and cell-to-cell communication, in turn, involved in regulating Azospirillum interactions with the surrounding microbial community. Despite being infrequently mentioned in metagenomics studies after its introduction as an inoculant, an increasing number of studies detected Azospirillum through molecular tools (mostly 16S rRNA sequencing) as part of diverse, even unexpected, microbiomes. This review focuses on Azospirillum traceability and the performance of the available methods, both classical and molecular. An overview of Azospirillum occurrence in diverse microbiomes and the less-known features explaining its notorious ability to colonize niches and prevail in multiple environments is provided.

Evaluation of contrast sensitivity in non-high-risk proliferative diabetic retinopathy treated with panretinal photocoagulation with and without intravitreal injections of ranibizumab

PURPOSE

To evaluate contrast sensitivity in non-high-risk, treatment-naïve proliferative diabetic retinopathy patients treated with panretinal photocoagulation and intravitreal injections of ranibizumab) versus panretinal photocoagulation alone.

METHODS

Sixty eyes of 30 patients with bilateral proliferative diabetic retinopathy were randomized into two groups: one received panretinal photocoagulation and ranibizumab injections (study group), while the other received panretinal photocoagulation alone (control group). All eyes were treated with panretinal photocoagulation in three sessions according to the Early Treatment Diabetic Retinopathy Study guidelines. Contrast sensitivity measurements were performed under photopic conditions (85 cd/m2) with the Visual Contrast Test Sensitivity 6500 chart, allowing for the evaluation of five spatial frequencies with sine wave grating charts: 1.5, 3.0, 6.0, 12.0, and 18.0 cycles per degree (cpd). Outcomes were measured in contrast sensitivity threshold scores among and within groups, from baseline to 1, 3, and 6 months.

RESULTS

Fifty-eight eyes (28 in the study group and 30 in the control group) reached the study endpoint. A comparative analysis of changes in contrast sensitivity between the groups showed significant differences mainly in low frequencies as follows: at month 1 in 1.5 cpd (p=0.001) and 3.0 cpd (p=0.04); at month 3 in 1.5 cpd (p=0.016), and at month 6 in 1.5 cpd (p=0.001) and 3.0 cpd (p=0.026) in favor of the study group.

CONCLUSIONS

In eyes of patients with non-high-risk proliferative diabetic retinopathy, panretinal photocoagulation treatment with ranibizumab appears to cause less damage to contrast sensitivity compared with panretinal photocoagulation treatment alone. Thus, our evaluation of contrast sensitivity may support the use of ranabizumab as an adjuvant to panretinal photocoagulation for the treatment of proliferative diabetic retinopathy.

Effects of cannabis and its components on the retina: a systematic review

Purpose: Cannabis is the most prevalent drug in the world and its consumption is growing. Cannabinoid receptors are present in the human central nervous system. Recent studies show evidence of the effects of cannabinoids on the retina, and synthesising the results of these studies may be relevant for ophthalmologists. Thus, this review adopts standardised, systematic review methodology to investigate the effects of exposure to cannabis and components on the retina.Methods: We searched five online databases for the combined terms for outcome ("retina") and exposure ("cannabis"). Eligibility of studies were conducted by two independent reviewers, and risk of bias was assessed.Results: We retrieved 495 studies, screened 229 studies, assessed 52 studies for eligibility, and included 16 studies for qualitative analysis. The cannabinoids most frequently investigated were delta-9-tetrahydrocannabinol (THC), abnormal cannabidiol, synthetic cannabinoid, and cannabidiol (CDB). The outcomes most studied were neuroretinal dysfunction, followed by vascular effects. The studies also included investigation of neuroprotective and anti-inflammatory effects and teratogenic effects.Conclusions: This review suggests that cannabinoids may have an important role in retinal processing and function.

Short-term effects of intravitreal bevacizumab in contrast sensitivity of patients with diabetic macular edema and optimizing glycemic control

AIMS

To analyze contrast sensitivity of intravitreal bevacizumab injections with optimizing glycemic control versus optimizing glycemic control (in combination with sham injections) in eyes with Diabetic Macular Edema (DME).

DESIGN

Prospective, interventional, masked, randomized controlled trial.

METHODS

Forty-one eyes of 34 patients with type 2 diabetes mellitus and DME with glycated hemoglobin (HbA1c) < 11% received either intravitreal bevacizumab injection (Group 1) or sham injection (Group 2) at 0 and 6 weeks along with optimizing glycemic control. Mean change in best-corrected visual acuity (BCVA), contrast sensitivity (CS), optical coherence tomography (OCT)-measured by central macular thickness (CMT) were compared and correlated at baseline, 2, 6 and 12 weeks.

RESULTS

The study showed a mean CS improved in group 1 from 1.14 ± 0.36 logCS to 1.32 ± 0.24 logCS and also in group 2 from 1.11 ± 0.29 logCS to 1.18 ± 0.29 logCS at 12 weeks (P = 0.12). CS and CMT promptly decreased in group 1 compared to group 2 at 2 weeks (ΔCS = 0.15 ± 0.25 vs. 0.03 ± 0.15 logCS; P = 0.04; ΔCMT = 116 ± 115 vs. 17 ± 71 μm; P = 0.01). There was a mean reduction of approximately 0.5% in HbA1c levels in both groups at 12 weeks (P = 0.002).

CONCLUSION

The use of bevacizumab in combination with optimizing glycemic control results in earlier improvement of contrast sensitivity in type 2 diabetes patients with DME. However, the optimizing glycemic control itself has shown also to be effective at 12 weeks. ClinicalTrials.gov Identifier: NCT02308644.

The effect of laser pan-retinal photocoagulation with or without intravitreal bevacizumab injections on the OCT-measured macular choroidal thickness of eyes with proliferative diabetic retinopathy

OBJECTIVES:

To investigate the effect of laser pan-retinal photocoagulation with or without intravitreal bevacizumab injections on macular choroidal thickness parameters in eyes with high-risk proliferative diabetic retinopathy.

METHODS:

High-risk proliferative diabetic retinopathy patients undergoing laser treatment were prospectively enrolled in this study. One eye was randomly selected for laser treatment combined with bevacizumab injections, study group, whereas the corresponding eye was subjected to laser treatment alone, control group. Spectral-domain optical coherence tomography with enhanced depth imaging was used to measure the macular choroidal thickness prior to and 1 month after treatment. Measurements in both groups were compared. Clinicaltrials.gov: NCT01389505.

RESULTS:

Nineteen patients (38 eyes) with a mean±standard deviation age of 53.4±9.3 years were evaluated, and choroidal thickness measurements for 15 patients were used for comparison. The greatest measurement before treatment was the subfoveal choroidal thickness (341.68±67.66 μm and 345.79±83.66 μm for the study and control groups, respectively). No significant difference between groups was found in terms of macular choroidal thickness measurements at baseline or after treatment. However, within-group comparisons revealed a significant increase in choroidal thickness parameters in 10 measurements in the study group and in only 5 temporal measurements in the control group when 1-month follow-up measurements were compared to baseline values.

CONCLUSIONS:

The macular choroidal thickness does not appear to be significantly influenced by laser treatment alone but increases significantly when associated with bevacizumab injections in patients with proliferative diabetic retinopathy and macular edema. Because bevacizumab injections reduce short-term laser pan-retinal photocoagulation-induced macular edema, our findings suggest that the choroid participates in its pathogenesis.

Metamizole versus placebo for panretinal photocoagulation pain control: a prospective double-masked randomized controlled study

BACKGROUND

Diabetic retinopathy is one of most common and threatening ocular diseases. Many of these patients need to be submitted to panretinal photocoagulation (PRP), experiencing a significant level of pain. The purpose of this study is to evaluate the effectiveness of oral metamizole in reducing pain during PRP in patients with proliferative diabetic retinopathy (PDR) and very severe non-proliferative diabetic retinopathy (VSNDR).

METHODS

Patients from a single center with PDR or VSNDR and indication of bilateral PRP were recruited for a double-masked, controlled, prospective study. The treated eyes were randomly assigned in two groups, and each patient had one eye assigned per group. Group A received 1000 mg of metamizole and group B received a placebo pill 40 min before the laser treatment. The groups were switched for the treatment of the fellow eye. Each patient scored the pain sensation immediately after each PRP section using Scott's visual analogue scale (VAS). The paired Student t test was used to measure the significance between the two groups VAS scores, with significance level adopted of p < 0.05.

RESULTS

Twenty-one patients were recruited. The level of pain was significantly lower when submitted to PRP after oral metamizole treatment compared to placebo (p = 0.002). The mean pain scores for groups A and B were 4.72 ± 1.708 and 5.89 ± 1.967, respectively. The minimum/maximum scores within groups A and B were 1/8 and 1/10, respectively.

CONCLUSIONS

The use of 1000 mg of metamizole 40 min before PRP significantly reduces the pain associated with the procedure in patients with PDR or VSNDR.

Case report: pneumatic retinopexy for the treatment of progressive retinal detachment in senile retinoschisis

Retinoschisis is an abnormal separation of the retinal layers and is asymptomatic in most cases. Enlargement of the area of retinoschisis and retinal tear and detachment are possible complications of the disease, and the treatment of retinoschisis is controversial. In this case report, we present a case of retinal detachment associated with senile retinoschisis in which pneumatic retinopexy was chosen as the treatment of choice and was performed successfully in one of the eyes. After a literature review on retinoschisis and pneumatic retinopexy for the treatment of associated retinal detachment, we found only one case that was successfully treated without drainage of subretinal fluid, using air as the filler. However, no previous reports have been found in the literature on the effectiveness of pneumatic retinopexy using C3F8 as the sole treatment for progressive retinal detachment in senile retinoschisis.

Efficacy of topical dorzolamide therapy for cystoid macular edema in a patient with MFRP-related nanophthalmos-retinitis pigmentosa-foveoschisis-optic disk drusen syndrome

PURPOSE

Mutations in the MFRP (membrane-type frizzled-related protein) gene leads to an entity characterized by retinitis pigmentosa, nanophthalmos, optic disk drusen, and macular changes, originally described as foveoschisis. Despite the association of MFRP gene mutation and increase in macular thickness, no treatment modality has been described for cystoid macular edema related to this particular entity so far.

METHODS

In this case report, a 52-year-old woman presented with nanophthalmos, optic disk drusen, retinitis pigmentosa, and increase in macular thickness. Genetic analysis revealed an MFRP gene mutation. The patient was treated with topical carbonic anhydrase inhibitors.

RESULTS

A progressive decrease in macular thickness and cystic changes was observed during the 2-month course of topical carbonic anhydrase inhibitor treatment, and best-corrected visual acuity improved from 20/100 to 20/50. Macular thickness remained stable after 6 months of follow-up.

CONCLUSION

Cystoid macular edema is part of the macular changes noted in the MFRP mutation-related nanophthalmos-retinitis pigmentosa-foveoschisis-optic disk drusen, syndrome. Taking into account that resolution of cystoid macular edema in patients with retinitis pigmentosa may delay an irreversible decrease in visual acuity, treatment should be considered when cystic changes are suspected. Topical carbonic anhydrase inhibitor was effective in decreasing macular thickness and cystic changes in the patient reported.

Choroidal bulging in patients with Vogt-Koyanagi-Harada disease in the non-acute uveitic stage

Background

Detection of choroidal inflammation in Vogt-Koyanagi-Harada (VKH) disease is still a challenge. Progression to sunset glow fundus has been observed despite apparent good clinical control of inflammation. Indocyanine green angiography (ICGA) permits choroid inflammation detection, though it is invasive, time consuming, and costly. The purpose of the present study is to report a sign indicative of probable inflammation on enhanced depth imaging spectral-domain optical coherence tomography (EDI-OCT): a localized increase in choroidal thickness with bulging of the outer retina (‘choroidal bulging’) in patients with VKH disease in the non-acute uveitic stage.

Findings

This is a retrospective observational study. The choroidal bulging was a particular finding observed in four eyes of three patients with VKH disease in the non-acute uveitic stage (median disease duration 55.3 ± 40.3 months, range 10 to 108). This study is part of an ongoing longitudinal study in patients with VKH disease carried out in the Uveitis Service, Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo, São Paulo, Brazil. In all eyes, the choroidal bulging was identified in the presence of anterior chamber cells and/or on fundus angiographic (fluorescein and indocyanine green) findings, indicative of disease activity. Changes in the thickness of the choroidal bulging accompanied the variation in the clinical and angiographic signs of inflammation.

Conclusion

The choroidal bulging is a particular finding detected on EDI-OCT that may indicate ongoing inflammation in the posterior segment of the eye. This EDI-OCT feature may assist in the treatment-monitoring of patients with Vogt-Koyanagi-Harada disease in the non-acute uveitic stage.

Effect of a single intravitreal bevacizumab injection on contrast sensitivity and macular thickness in eyes with macular edema from central retinal vein occlusion: a prospective, nonrandomized, three-month follow-up study

PURPOSE

To evaluate the results of intravitreal bevacizumab (IVB) injection on contrast sensitivity (CS), best-corrected visual acuity (BCVA), foveal thickness (FT) and macular volume (MV) as measured by optical coherence tomography in patients with macular edema (ME) from central retinal vein occlusion (CRVO).

METHODS

Sixteen consecutive eyes from 16 patients with ME from unilateral CRVO were treated with a single IVB injection. The CS, BCVA, FT and MV measurements were obtained before the treatment and 1 and 3 months after the injection.

RESULTS

CS demonstrated significant improvement at all spatial frequencies - 1.5, 3, 6, 12 and 18 cycles per degree (cpd) - 1 month after the injection and at 6 cpd at the 3-month follow-up. The mean BCVA measurements in log of the minimum angle of resolution (logMAR) units improved from 1.03 at baseline to 0.83 logMAR 1 month after the injection, but worsened to 0.97 logMAR at 3 months. The mean baseline FT ± standard deviation (SD; 620.06 ± 177.60 µm) was reduced significantly 1 month (270.93 ± 74.17 µm) and 3 months (535.56 ± 222.33 µm) after the treatment. The mean baseline MV ± SD (12,765.56 ± 3,769.70 mm(3)) was reduced significantly at the 1-month (8,324.93 ± 932.04 mm(3)) and 3-month (11,319.44 ± 3,044.74 mm(3)) follow-up visits.

CONCLUSIONS

IVB improved CS, BCVA, FT and MV within a short time period (1 month). Although VA was not improved at 3 months, improvements were observed for CS, FT and MV, which indicates that, despite ME recurrence, there still was some benefit to visual function.

Retinal involvement of Paracoccioidomycosis: A Case Report

Purpose: to describe the clinicopathologic features and treatment of a rare case of systemic paracoccidioidomycosis with choroidal and retinal involvement. Design: retrospective interventional case report. Participant: A 36-year-old young man with visual impairment in left eye with anterior uveitis and presence of whitish perimacular choroidal nodule, multiple underlying whitish spots and mid-periphery exudative retinal detachment. A primary extensive work-up for systemic infectious, autoimmune, neoplasic or inflammatory conditions was performed and high-resolution computer tomography scan demonstrated asymmetric parietal thickening of the trachea and bilateral diffuse multiple lobular opacities. Pulmonary bronchoscopy/biopsy of larynx, trachea and bronchial tube were also performed. Histopathological evaluation showed characteristic of Paracoccidioidomycosis. Intervention: Patient was treated with oral sulphadiazine (1.5 g/day). Main Outcome Measures: Anterior uveitis, retinal examination, histopathological evaluation and primary clinical outcome were observed during systemic treatment. Results: After 3 months of irregular treatment, choroidal lesions decreased in size forming atrophic scars and fibrotic spots; however visual acuity did not show any improvement. Conclusion: We report a rare case of systemic paracoccidioidomycosis with choroidal and retinal involvement treated with oral sulphadiazine.

Unusual macular thickness in Alport syndrome: case report

This case report describes the presence of bilateral macular atrophy in a patient with Alport syndrome and compares this finding with literature. At fundoscopy, there was a discrete circumscribed macular thinning showing intense retinal pigment epithelium color and the presence of whitish circular retinal lesions ("dots" and "flecks") at nasal mid periphery of both eyes. Optical coherence tomography showed bilateral partial atrophy of the neurosensory retina in the macula, with a greater extent in the temporal region. This case describes a rare ophthalmological finding in Alport syndrome and important to be recognized for a precise diagnosis as well as for determining visual prognosis.

Indocyanine green angiography findings in patients with long-standing Vogt-Koyanagi-Harada disease: a cross-sectional study

BACKGROUND

To investigate indocyanine green angiography (ICGA) findings in patients with long-standing Vogt-Koyanagi-Harada (VKH) disease and their correlation with disease activity on clinical examination as well as with systemic corticosteroid therapy.

METHODS

Twenty-eight patients (51 eyes) with long-standing (≥6 months from disease onset) VKH disease whose treatment was tapered based only in clinical features were prospectively included at a single center in Brazil. All patients underwent standardized clinical evaluation, which included fundus photography, fluorescein angiography and ICGA. Clinical disease activity was determined based in the Standardization in Uveitis Nomenclature Working Group. Fisher exact test and logistic regression models were used for statistical analysis.

RESULTS

Disease-related choroidal inflammation on ICGA was observed in 72.5% (31 of 51 eyes). Angiographic findings suggestive of (choroidal and/or retinal) disease activity were not observed on FA. Clinically active disease based on clinical evaluation was observed in 41.2% (21 of 51 eyes). In these 21 eyes, disease-related choroidal inflammation on ICGA was observed in 76.2% (16 of 21 eyes); in the remaining eyes (without clinical active disease) disease-related choroidal inflammation on ICGA was observed in 70.0% (21 of 30 eyes). In respect to systemic corticosteroid therapy, 10 patients (18 of 51 eyes) were under treatment with prednisone. In these 10 (18 of 51 eyes) patients, disease-related choroidal inflammation on ICGA was observed in 83.3% (15 of 18 eyes); in the remaining patients (33 of 51 eyes) disease-related choroidal inflammation on ICGA was observed in 66.7% (22 of 33 eyes).

CONCLUSION

ICGA findings suggestive of disease-related choroidal inflammation were observed in a considerable proportion of patients with long-standing VKH disease, independent of the inflammatory status of the disease on clinical examination or current use of systemic corticosteroid. Therefore, the current study reinforces the crucial role of ICGA to assist the management and treatment of patients with long-standing VKH disease.

Combined laser and intravitreal triamcinolone for proliferative diabetic retinopathy and macular edema: one-year results of a randomized clinical trial

PURPOSE

To evaluate laser combined with intravitreal triamcinolone acetonide (IVTA) for the management of patients with proliferative diabetic retinopathy (PDR) and clinically significant macular edema (CSME).

DESIGN

Randomized clinical trial.

METHODS

settings: Single center. study population: Twenty-two patients with bilateral treatment-naïve moderate PDR and CSME. intervention: Laser (panretinal and macular) photocoagulation was performed in each eye, followed by IVTA in one randomly assigned eye. Best-corrected visual acuity (BCVA), fundus photography, and optical coherence tomography were performed at baseline and at months 1, 3, 6, 9, and 12. main outcome measures: Changes in BCVA, central macular thickness (CMT), and total macular volume (TMV).

RESULTS

The mean logarithm of the minimal angle of resolution (logMAR) BCVA improved significantly, and mean CMT and TMV were significantly reduced in the IVTA group compared with the laser-only group (controls) at all study follow-up visits (P < .001). The mean logMAR BCVA (Snellen equivalent) was 0.44 (20/50(-2)) for the IVTA group and 0.38 (20/50(+1)) for the controls at baseline, and 0.12 (20/25(-1)) for the IVTA group and 0.32 (20/40(-1)) for the controls at 12 months (P < .001). The mean CMT and TMV were, respectively, 360 microm and 8.59 mm(3) for the IVTA group and 331 microm and 8.44 mm(3) for the controls at baseline, and 236 microm and 7.32 mm(3) for the IVTA group and 266 microm and 7.78 mm(3) for the controls at 12 months (P < .001).

CONCLUSIONS

The combination of laser photocoagulation with IVTA was associated with improved BCVA and decreased CMT and TMV when compared with laser photocoagulation alone for the treatment of moderate PDR with CSME.

How much information do medical practitioners and endocrinologists have about diabetic retinopathy?

OBJECTIVE

The objective of this study was to use a questionnaire to evaluate knowledge concerning diabetic retinopathy among the physicians present at the 12th Latin American Congress on Diabetes held in São Paulo, Brazil, September 2004.

METHODS

A questionnaire about their experience and management of patients with diabetes mellitus and the ophthalmologic examination was administered to 168 endocrinologists attending the meeting.

RESULTS

Among the 168 physicians, only 36.9% correctly referred patients with diabetes type 1 to an ophthalmologist, whereas 86.9% referred patients with the type 2 disorder as recommended by the American Academy of Ophthalmology. Regarding the correct indication for screening for diabetic retinopathy, more physicians who had received their degree less than 5 years previously implemented this practice (54.8%), as opposed to those who had received their MD 20 years or more ago (22.6%). Regarding their experience in funduscopy during their specialty training, 52.4% claimed to have experience, but only 21.4% of those interviewed performed this examination on their patients. According to 84.5% of the interviewees, the fundus examination influenced their clinical treatment program.

CONCLUSION

Our study demonstrates that medical knowledge among medical practitioners and endocrinologists on preventive measures and periodicity of diabetic retinopathy examinations appears to be far from ideal for diabetes type 1, but satisfactory for diabetes type 2. Therefore, refresher courses emphasizing the correct management of diabetic patients are necessary, because the social and economic impact of retinopathy is significant.

Chloroquine-induced bull’s eye maculopathy in rheumatoid arthritis: related to disease duration?

Chloroquine diphosphate has been used in the treatment of various rheumatic diseases, including rheumatoid arthritis. The most important of its side effects is retinopathy. If not diagnosed early, this lesion can evolve into irreversible bull's eye maculopathy and visual loss. The aim of this study was to define the outcome of chloroquine-induced maculopathy after cessation of chloroquine therapy and also to identify the risk factors involved in case of retinopathy evolution. The design of this cohort study was longitudinal and retrospective. Over the period spanning 2000 to 2005, out of 607 medical records of patients with rheumatoid arthritis followed in our Division of Rheumatology, 27 had been diagnosed with chloroquine-induced maculopathy through clinical funduscopy with pupil dilation. In all cases, there was immediate chloroquine intake cessation. After a mean time of 5 years, 16 of these patients were available for follow-up and underwent a new ophthalmologic evaluation by funduscopy, using biomicroscopy and angiofluorescein when necessary. Sequelae maculopathy were reconfirmed in all 16 cases, but progression to advanced stage (bull's eye maculopathy) was found in half of the cohort, even though chloroquine had been suspended. All patients complained of visual alterations, but without progression. Comparison between patient groups with and without bull's eye maculopathy revealed a statistically significant longer rheumatoid arthritis disease history in the former group. Also, the bull's eye group had higher dose intakes of chloroquine and over a longer period compared to the other group, but not statistically significant. This study corroborates the progression of maculopathy even after cessation of chloroquine intake, pointing out the need for careful screening in the high-risk patients. Furthermore, it indicates that duration of rheumatoid arthritis disease could be a possible factor linked to worse prognosis of chloroquine-induced maculopathy.

Mitomycin C as adjunctive therapy with glaucoma implant surgery

Twenty-one eyes of 21 patients with refractory glaucoma underwent glaucoma surgery involving placement of a modified Molteno implant and intraoperative application of mitomycin C. Sixteen eyes (76.2%) had an intraocular pressure (IOP) of 21 mm Hg or less after a mean follow up of 9.4 +/- 6.4 months; additional medication was needed in six eyes. Major complications included early flat anterior chamber (42.9%), implant plate erosion (9.5%), tube erosion (4.8%), late hypotony (4.8%), tube-corneal touch (4.8%), and phthisis bulbi after choroidal hemorrhage (4.8%). Only one patient had a high IOP due to decreased filtration through the implant. These results suggest that glaucoma implant surgery with the adjunctive use of mitomycin C may be useful in eyes with refractory glaucoma.