Ocular repercussions in COVID-19 patients: structural changes of the retina and choroid

BACKGROUND

Neurotropic capabilities of SARS-COVs allow viruses to reach the central nervous system by hematogenous neuronal dissemination. The human retina, as an extension of the Central Nervous System, may have some neurodegenerative and/or vascular modifications related to COVID-19.

OBJECTIVES

To evaluate choroidal and inner neural layers in participants previously recovered from COVID-19 compared to the control group using optical coherence tomography.

METHODS

With a cross-sectional approach, the sample (n = 96), constituted by patients who have recovered from COVID-19 (n = 56) and healthy participants control group (n = 40) were ophthalmologically characterized. The neurodegenerative and vascular histological assessment was performed using SD-OCT and the mean thickness was measured in Early Treatment Diabetic Retinopathy Study (ETDRS) subfields. Retinal nerve fiber layer, Ganglion cell layer and subfoveal choroidal thickness were obtained through semi-automatic measurement.

RESULTS

A total of 40 controls (27 women [67.5%]) and 56 COVID-19 participants (34 women [60.8%]) were included in this first report. There were retinal thickness significant differences in nearly all inner ETDRS subfields: nasal 3 mm (p = .025), I3 (p = .049), and temporal 3 mm (p = .009). Also, a decrease in neural layers was found in the nasal 3 mm (p = .049) and temporal 3 mm (p = .029) during ganglion cell layer assessment. The peripapillary retinal nerve fiber layer thickness was thinner in the COVID-19 group in superior temporal (p = .019), nasal (p = .002), inferior temporal (p = .046) and global (p = .014). Concerning the subfoveal choroidal measurement, an increase was observed in the COVID-19 group (p = .002).

CONCLUSION

Participants who had recovered from COVID-19 showed a non-glaucomatous neuropathy trend pattern. We found differences closer to the classic description of the "bow-tie" observed in other neurological as compressive neuropathies at the chiasma location. OCT assessment also showed an increase in choroidal thickness as a result of vascular changes.

Ultrathin DSAEK versus DMEK - Review of systematic reviews

The efficacy and safety of Descemet's membrane endothelial keratoplasty (DMEK) and ultrathin Descemet stripping automated endothelial keratoplasty (UT-DSAEK) have been recently compared in several systematic reviews (SRs). The aim of this study was to assess the evidence quality of such SRs, in order to obtain a scientifically rigorous comparison between the two techniques. We performed a systematic review of SRs and meta-analyses comparing the efficacy and safety between UT-DSAEK and DMEK up to 24th March 2023, using 3 electronic databases (PubMed, Cochrane Library, Google Scholar) plus manual reference search. Specific outcomes analyzed included best-corrected visual acuity (BCVA), endothelial cell density (ECD), rebubbling rate, and other postoperative complications. Of 90 titles/abstracts screened, four SRs met the inclusion criteria. All SRs adequately analyzed potential bias of the included studies. One SR raised concern for potential literature search bias and two SRs have heterogeneity in some outcomes analyzed. All SRs found higher BCVA after DMEK, but one SR reported significant heterogeneity. All SRs found significant heterogeneity in ECD analysis, with one SR providing inconsistent analysis of this outcome. Three SRs analyzed rebubbling rates, favoring UT-DSAEK over DMEK. Three SRs concluded a higher overall complication rate after DMEK, although rebubbling may be a confounding factor. This systematic review clarifies the strengths and weaknesses of published SRs and reinforces the conclusion that DMEK leads to superior visual outcomes compared to UT-DSAEK, with the trade-off of higher rebubbling rates and possibly other postoperative complications. Studies with longer follow-up are needed to ascertain these differences between procedures.

Descemet’s Membrane Endothelial Keratoplasty for Corneal Endothelial Failure Secondary to Three Types of Phakic Intraocular Lens – Retrospective Study

Purpose

To analyze the outcomes of Descemet's membrane endothelial keratoplasty (DMEK) for corneal endothelial failure secondary to phakic intraocular lens implantation (PIOL) at a reference center for corneal transplantation in Spain.

Design

Retrospective, single-surgeon case series.

Methods

Single-center analysis of patients who underwent DMEK for PIOL-related corneal decompensation between July 2011 and July 2020 with at least 6 months of follow-up postoperatively. Primary outcome was final best-corrected visual acuity (BCVA, logMAR) compared to pre-DMEK BCVA. Secondary outcomes analyzed included post-DMEK refractive spherical equivalent, endothelial cell loss (%ECL), and graft failure.

Results

Sixteen eyes (14 patients) underwent DMEK for PIOL-related corneal decompensation. Mean (SD) time to PIOL explantation was 9.3 (5.0) years, and median (P25-P75) time between PIOL explantation and DMEK surgery was 3 (2-4) months. Median pre-DMEK BCVA was 0.80 (1.08-0.60) logMAR. A statistically significant improvement in BCVA was observed 1 month after DMEK (p = 0.001), and median final BCVA was 0.15 (0.0-0.35) logMAR (p = 0.002). Mean %ECL was 55.6 (18.7) % at 2-year follow-up and 61.7 (11.7) % in eyes with over 4 years of follow-up. Two eyes required re-bubbling (12.5%), one of which ended in primary graft failure (6.2%) and one eye had late endothelial graft failure (LEGF) at 4-year follow-up (1/15 grafts, 6.7%).

Conclusion

In patients with PIOL-related corneal decompensation, DMEK leads to good and clinically significant refractive and visual outcomes in the medium-long term, with a good safety profile. Prospective studies are encouraged to ascertain whether these cases are at increased risk of accelerated endothelial cell loss and LEGF.

Outcomes of cystoid macular edema following Descemet's membrane endothelial keratoplasty in a referral center for keratoplasty in Spain: retrospective study

The aim of this study was to analyze the outcomes of eyes with visually significant cystoid macular œdema (vs-CMO) after Descemet membrane endothelial keratoplasty (DMEK) in a referral center for keratoplasty in Spain. We conducted a retrospective, single-surgeon case series of eyes that developed post-DMEK vs-CMO performed between January 2011 and December 2020. Data collected included: indication for DMEK; biometric data; ocular comorbidities; past medical history; time to detection of vs-CMO after DMEK (T, weeks); best-corrected visual acuity (BCVA, logMAR) and central retinal thickness (CRT, µm) at diagnosis of vs-CMO, after resolution of CMO, and at last follow-up; and management strategy. Main outcomes analyzed were incidence of vs-CMO, improvement in BCVA and CRT after treatment of vs-CMO. Of 291 consecutive DMEK surgeries, 14 eyes of 13 patients (4.8%) developed vs-CMO. Five patients (38.5%) had history of CMO, and 28.6% of eyes had ophthalmic comorbidities. Median (P25-P75) T was 4 (3-10) weeks. Treatment success was observed in 12/13 eyes (92.3%), two of which required second-line treatment. In successful cases (median time-to-resolution 3.0 (2.0-3.5) months), median BCVA improved from 0.60 (0.40-0.80) logMAR to 0.30 (0.15-0.40) logMAR (p = 0.002) after treatment, and median CRT improved from 582.5 (400.0-655.0) µm to 278.0 (258.0-294.0) µm (p = 0.005). In our study, we found a 4.8% rate of post-DMEK vs-CMO, with most cases occurring in the first 3 months after surgery. Good functional and anatomical outcomes are expected in most eyes, without treatment-related complications or implications in graft outcomes. Additional studies are encouraged to determine a standardized protocol for post-DMEK vs-CMO.

Same-day initiation of oral pre-exposure prophylaxis among gay, bisexual, and other cisgender men who have sex with men and transgender women in Brazil, Mexico, and Peru (ImPrEP): a prospective, single-arm, open-label, multicentre implementation study

BACKGROUND

Although gay, bisexual, and other cisgender men who have sex with men (MSM) and transgender women have the highest HIV burden in Latin America, pre-exposure prophylaxis (PrEP) implementation is poor. We aimed to assess the feasibility of same-day oral PrEP delivery in Brazil, Mexico, and Peru.

METHODS

Implementation PrEP (ImPrEP) was a prospective, single-arm, open-label, multicentre PrEP implementation study conducted in Brazil (14 sites), Mexico (four sites), and Peru (ten sites). MSM and transgender women were eligible to participate if they were aged 18 years or older, HIV-negative, and reported one or more prespecified criteria. Enrolled participants received same-day initiation of daily oral PrEP (tenofovir disoproxil fumarate [300 mg] coformulated with emtricitabine [200 mg]). Follow-up visits were scheduled at week 4 and quarterly thereafter. We used logistic regression models to identify factors associated with early loss to follow-up (not returning after enrolment), PrEP adherence (medication possession ratio ≥0·6), and long-term PrEP engagement (attending three or more visits within 52 weeks). This study is registered at the Brazilian Registry of Clinical Trials, U1111-1217-6021.

FINDINGS

From Feb 6, 2018, to June 30, 2021, 9979 participants were screened and 9509 were enrolled (Brazil n=3928, Mexico n=3288, and Peru n=2293). 543 (5·7%) participants were transgender women, 8966 (94·3%) were cisgender men, and 2481 (26·1%) were aged 18-24 years. There were 12 185·25 person-years of follow-up. 795 (8·4%) of 9509 participants had early loss to follow-up, 6477 (68·1%) of 9509 were adherent to PrEP, and 5783 (70·3%) of 8225 had long-term PrEP engagement. Transgender women (adjusted odds ratio 1·60, 95% CI 1·20-2·14), participants aged 18-24 years (1·80, 1·49-2·18), and participants with primary education (2·18, 1·29-3·68) had increased odds of early loss to follow-up. Transgender women (0·56, 0·46-0·70), participants aged 18-24 years (0·52, 0·46-0·58), and those with primary education (0·60, 0·40-0·91) had lower odds of PrEP adherence. Transgender women (0·56, 0·45-0·71), participants aged 18-24 years (0·56, 0·49-0·64), and those with secondary education (0·74, 0·68-0·86) had lower odds of long-term PrEP engagement. HIV incidence was 0·85 per 100 person-years (95% CI 0·70-1·03) and was higher for transgender women, participants from Peru, those aged 18-24 years, Black and mixed-race participants, and participants who were non-adherent to PrEP.

INTERPRETATION

Same-day oral PrEP is feasible for MSM and transgender women in Latin America. Social and structural determinants of HIV vulnerability need to be addressed to fully achieve the benefits of PrEP.

FUNDING

Unitaid, WHO, and Ministries of Health in Brazil, Mexico, and Peru.

TRANSLATIONS

For the Portuguese and Spanish translations of the abstract see Supplementary Materials section.

Self-testing for SARS-CoV-2 in São Paulo, Brazil: results of a population-based values and attitudes survey

Background

Brazil is among the countries in South America where the COVID-19 pandemic has hit the general population hardest. Self-testing for SARS-CoV-2 infection is one of the community-based strategies that could help asymptomatic individuals at-risk of COVID-19, as well as those living in areas that are difficult for health personnel to reach, to know their infectious status and contribute to impeding further transmission of the virus.

Methods

A population-based survey was conducted in November 2021, to assess the acceptability of rapid SARS-CoV-2 antigen self-testing among the population of São Paulo. Survey respondents were approached at more than 400 different street-points that were randomly selected using a five-stage randomization process. A 35-item structured questionnaire was used. Dependent variables for our analyses were the likelihood to use and willingness to pay for self-testing, and the likelihood of taking preventive measures to prevent onward transmission of SARS-CoV-2 following a reactive self-test result. Bivariate and multivariate regression analyses were performed.

Results

Overall, 417 respondents (44.12% female) participated; 19.66% had previously had COVID-19 disease. A minority (9.59%) felt at high-risk of COVID-19. The majority of both females and males (73.91% and 60.09%, respectively) were in favor of the idea of SARS-CoV-2 self-testing. Overall, if self-tests were available, almost half of the sample would be very likely (n = 54, 12.95%) or likely (n = 151, 36.21%) to use one if they felt they needed to. Upon receiving a positive self-test result, the majority of respondents would communicate it (88.49%), request facility-based post-test counseling (98.32%), self-isolate (97.60%), and warn their close contacts (96.64%).

Conclusion

Rapid SARS-CoV-2 antigen self-testing could be an acceptable screening tool in São Paulo. The population would be empowered by having access to a technology that would allow them to test, even if asymptomatic, when traveling, or going to work or school. If there is a surge in the incidence of cases, self-testing could be a good approach for mass case detection by Brazil’s already overstretched Unified Health System.

DMEK for the treatment of interface fluid syndrome secondary to failed DSAEK graft: A case report and review of the literature

Purpose

Observations

Conclusions and Importance

Acute corneal allograft rejection following SARS-CoV-2 vaccination-A systematic review

All documented cases of acute corneal allograft rejection following SARS-CoV-2 vaccination were examined, to characterize possible risk factors and graft outcomes. Comprehensive search (4 electronic databases: PubMed, CENTRAL, ClinicalTrials.gov, Google Scholar, plus manual search in articles' reference lists) until March 1st 2022 to identify studies reporting acute corneal allograft rejection following SARS-CoV-2 vaccination; study protocol was developed in line with PRISMA statement. We analysed demographics, allograft type, rejection prophylaxis regime at the time of vaccination, transplantation-to-vaccination time (G-Vt), vaccination-to-immune reaction onset time (V-Rt), management, best-corrected visual acuity before and after rejection, and graft survival. Of 169 titles/abstracts screened, 16 studies (n  = 36 eyes) met the inclusion criteria. Fourteen eyes (38.9%) had received >1 graft, and 11.1% of cases had history of immune reactions; 52.9% of cases occurred after the first dose. Median (P25-P75) G-Vt was 48 (10-78) months; median V-Rt was 9 (7-14) days. In eyes with resolved rejection, median time-to-resolution was 3 (1-4) weeks. Four eyes (11.1%) had partial resolution of corneal decompensation, and 5 grafts (13.9%) failed. Acute corneal allograft rejection after SARS-CoV-2 vaccination is a rare event, but may occur any time post-keratoplasty. Early recognition and prompt, aggressive treatment is warranted to optimize vision and graft survival. Well-known risk factors for rejection may be confounding factors, including the high proportion of cases with a history of previous grafts and the rejection prophylaxis regimes at the time of vaccination. Increasing immunosuppressants in the peri-vaccination period may decrease the risk of immune reactions, especially in high-risk cases.

Photorefractive keratectomy after DMEK for corneal decompensation by phakic IOL

PURPOSE

To provide the first description of photorefractive keratectomy (PRK) for the correction of mild residual refractive error after Descemet membrane endothelial keratoplasty (DMEK).

METHODS

Case report.

RESULTS

A 45 year-old woman presenting with phakic intraocular lens (PIOL)-related corneal decompensation underwent staged DMEK surgery following PIOL explantation and cataract surgery. Eighteen months after DMEK, uncorrected distance visual acuity (UDVA) was 20/60 and best-corrected visual acuity (BCVA) was 20/22, with a stable refraction. The patient requested refractive surgery to decrease spectacle dependance, and wavefront-optimized PRK was performed. At last follow-up observation thirty-three months after PRK (54 months after DMEK surgery), UDVA was 20/20, the cornea remained clear without signs of rejection or endothelial failure, and the endothelial cell loss rate was not accelerated after PRK.

CONCLUSION

Since long-term visual and refractive stability can be expected after DMEK, PRK may be a particular safe and effective approach for the correction of mild residual refractive errors after DMEK. However, we consider that surgeons must exercise caution when considering keratorefractive surgery in these eyes due to postoperative changes in corneal curvature and thickness, and further studies are encouraged.

Secondary Endothelial Keratoplasty-A Narrative Review of the Outcomes of Secondary Corneal Endothelial Allografts

BACKGROUND

We review the literature on the efficacy and safety outcomes of secondary Descemet stripping endothelial keratoplasty (DSEK) and Descemet membrane endothelial keratoplasty (DMEK).

METHODS

Literature search of English-written publications up to September 27, 2020 in PubMed database, using the terms "endothelial keratoplasty" in combination with keywords "secondary" or "repeat." In addition, we manually searched the references of the primary articles.

RESULTS

Twenty-seven studies (n = 651 eyes) were retained and reviewed, including 10 studies on repeat DSEK, 8 studies on repeat DMEK, 6 studies of DMEK following DSEK, and 3 studies of DSEK after failed DMEK. All studies reported significant improvement in visual acuity after secondary endothelial keratoplasty (EK). Twelve studies compared visual outcomes between primary and secondary EK, reporting conflicting findings. Sixteen studies reported endothelial cell loss rates after secondary EK, and only 1 study reported significantly increased endothelial cell loss rates compared with primary EK. Allograft rejection episodes occurred in 1.8% of eyes (range, 0%-50%). Six studies compared complication rates between primary and secondary EK eyes, and only 1 study found a higher median number of complications. However, 2 studies reported higher regraft failure rates compared with primary EK eyes.

CONCLUSIONS

Secondary EK is surgically feasible and renders significant visual improvement after failed primary EK, although it is not clear whether visual outcomes and allograft survival are comparable with primary EK, raising the question of whether secondary EK eyes are "low risk" as primary EK eyes. Further larger, prospective studies are encouraged to obtain additional quality data on secondary corneal endothelial allotransplantation.

Retinal and choroidal thickness changes in systemic lupus erythematosus patients: a longitudinal study

BACKGROUND/OBJECTIVES

To prospectively evaluate changes in peripapillary retinal nerve fibre layer (pRNFL), in all macular layers and in choroidal thickness (CT) in a cohort of systemic lupus erythematosus (SLE) patients without ophthalmologic manifestations. To associate those changes with ophthalmic characteristics, disease activity state, medication and systemic comorbidities.

SUBJECTS/METHODS

Prospective cohort study of 68 previously diagnosed SLE patients. In two study visits (V1 and V2) at least 12 months apart, patients underwent a complete ophthalmologic examination including spectral domain-optical coherence tomography (SD-OCT) and an autoimmune disease specialist assessment. Automatic retinal segmentation was performed. pRNFL was determined globally and in the six peripapillary sectors and each macular layer thickness was determined in the nine early treatment diabetic retinopathy study (ETDRS) subfields. CT was manually measured at 13 locations in the posterior pole. Only one eye per patient was randomly selected for inclusion. Generalised linear mixed effects models were employed.

RESULTS

Sixty-five patients completed the study. The median follow-up time was twelve months. At V2, pRNFL was significantly thinner globally (p = 0.006) and in the temporal inferior sector (p = 0.017). Patients under chronic medication with anticoagulants or antihypertensives had significantly thinner pRNFL in some locations. No significant changes were observed in macular layers or choroidal thickness between study visits.

CONCLUSIONS

SLE patients presented early SD-OCT signs of neurodegeneration, evidenced by a progressive reduction in pRNFL thickness. Regardless of study visit, baseline chronic medication with anticoagulants or antihypertensives was associated with lower pRNFL thickness, accounting for a deleterious effect of cardiovascular risk factors.

Corneal Subbasal Nerve Plexus Evaluation by in Vivo Confocal Microscopy in Multiple Sclerosis: A Potential New Biomarker

Purpose/Aim: Our study aims to evaluate corneal subbasal nerve plexus morphology by in vivo corneal confocal microscopy (CCM) in Multiple Sclerosis (MS) patients and to explore its potential ability to distinguish between MS patients and healthy subjects.Materials and methods: Cross-sectional study, including 60 MS patients and 22 healthy subjects. Expanded Disability Status Scale (EDSS) was used to assess neurological disability. All participants underwent full ophthalmology evaluation, CCM and optical coherence tomography (OCT). Corneal nerve fibre density (CNFD), branch density (CNBD), fibre length (CNFL) and fibre tortuosity (CNFT) were analysed. Generalized additive regression models were used to analyse the data.Results: Compared to controls, MS patients had lower CNFD, CNBD and CNFL (p < .001) and higher CNFT (p = .002). The area under the ROC curve to distinguish MS patients from healthy controls with CNFD and CNBD was 0.84 (95%CI: 0.75 to 0.93; 95%CI: 0.75 to 0.92, respectively). A nonlinear association between EDSS and CNFD was found, with an initial density increase followed by a significant decrease until more severe disability status. EDSS was associated with CNFL and CNBD, with values being significantly lower for patients with an EDSS > 2.5 (-2.06 mm/mm2; 95%CI: -3.84 to -0.28; p = .027 and -8.70 branches/mm2; 95%CI: -14.69 to -2.71; p = .006, respectively). An optic neuritis (ON) history did not influence CCM parameters.Conclusions: Our results confirm CCM parameters' potential to differentiate MS patients from healthy subjects, not being influenced by a previous ON history. A significant relationship between patient's disability and corneal nerve morphology was also found.

A Review of Neuro-Ophthalmological Manifestations of Human Coronavirus Infection

Introduction

Human coronavirus (HCoVs) are a group of viruses with recognized neurotropic and neuroinvasive capabilities. The reports on the neurological and ocular findings are increasing day after day and several central and peripheral neurological manifestations are already described. However, none specifically describes the neuro-ophthalmological manifestation of HCoVs. This is the first article specifically reviewing neuro-ophthalmological manifestations of HCoVs infection.

Methods

PubMed and Google Scholar databases were searched using the keywords: coronaviridae, coronavirus, COVID-19, SARS-CoV-2, SARS-CoV-1, MERS, ocular, ophthalmology, ophthalmological, neuro-ophthalmology, neurological, manifestations. A manual search through the reference lists of relevant articles was also performed. There were no restrictions concerning language or study type and publications not yet printed but available online were considered.

Results

Coronavirus eye involvement is not frequent and includes mostly a typical viral follicular conjunctivitis. Recently, retinal anatomical alterations were described using optic coherence tomography. Neuro-ophthalmological symptoms and signs can appear isolated or associated with neurological syndromes. The manifestations include headache, ocular pain, visual impairment, diplopia, and cranial nerve palsies secondary to Miller Fisher syndrome, Guillain-Barré syndrome, or encephalitis, and nystagmus.

Conclusion

Neurological and neuro-ophthalmological syndromes, symptoms, and signs should not be neglected and a complete ophthalmological examination of these patients should be performed to fully describe ocular manifestations related to HCoVs. We believe that major ocular and neuro-ophthalmological manifestations reports lack due to safety issues concerning detailed ophthalmological examination; on the other hand, in a large number of cases, the presence of life-threatening coronavirus disease hinders ocular examination and ophthalmologist’s visit to the intensive care unit.

COVID-19: An Ophthalmologist’s Perspective

In just one hundred years, the world has been through five pandemics. Lessons of the past have not prevented a new virus from being responsible for a fifth wave of deaths worldwide, even with scientific advances and the rapid response of societies that, for the most part, anticipated the political and economic response. A century after the end of the Spanish Flu (1918/19), in December 2019, the world has watched the beginning of the second pandemic of the 21st century, coronavirus disease 2019 (COVID-19) caused by a new severe acute respiratory coronavirus syndrome-2 (SARS-CoV-2).The eye can not only be the entry point for coronaviruses, but also a target organ. Conjunctivitis, uveitis, vasculitis, retinitis and optic neuritis have all been documented in animal models studies.In this article, we review the possible roles of the visual system/ocular tissues as an entryway, and the potential ophthalmic manifestations of human SARS-CoV-2 infections. This review article will also highlight the most effective ways for protecting and preventing the spread of the virus.

Optic neuropathy due to chronic lymphocytic leukemia: The first manifestation of the disease

Purpose

Chronic lymphocytic leukemia (CLL) is the most common lymphoproliferative disorder in the western world. The involvement of the central nervous system (CNS) or the optic nerve in CLL, however, is rare. We report a case of a previously untreated patient with CLL whose first manifestation of the disease was a progressive visual loss caused by optic neuropathy.

Observations

Clinical manifestations, optical coherence tomography (OCT), and automated visual fields pointed to the diagnosis of neuropathy. Leukemic involvement of the CNS was confirmed after cells suggestive of CLL were found by cerebrospinal fluid analysis. Optic nerve infiltration is thought to be the cause of this optic neuropathy, and the clinical course and treatment are described herein.

Conclusions

When readily diagnosed, optic nerve infiltration is a rare, yet manageable complication of CLL.

Ocular involvement in systemic lupus erythematosus patients: a paradigm shift based on the experience of a tertiary referral center

Objective

To evaluate ocular involvement in a cohort of systemic lupus erythematosus (SLE) patients of a tertiary referral center and to compare the results with the existing literature.

Methods

Patients underwent a complete ophthalmological evaluation, including visual acuity, slit-lamp examination, fluorescein staining, Schirmer-I test, Goldmann applanation tonometry, fundoscopy, 10-2 automated threshold visual fields, fundus autofluorescence and spectral-domain optical coherence tomography to screen for hydroxychloroquine (HCQ) macular toxicity.

Results

A total of 161 patients (16 men and 145 women) were enrolled in this study. The mean age was 47.6 years and the mean disease duration was 11.5 years. Fifty patients (31.1%) had at least one ocular manifestation of SLE. The most frequent manifestation was dry eye syndrome (12.4%), immediately followed by cataracts (11.2%) and HCQ macular toxicity (11.2%). Among patients with HCQ maculopathy, two presented with an atypical spectral-domain optical coherence tomography pattern. Five patients (3.1%) presented with glaucoma, two patients (1.2%) presented with SLE retinopathy while only one presented with lupus choroidopathy (0.6%).

Conclusions

Compared with previous studies, we conclude there has been a significant reduction in disease-related ocular complications, particularly those associated with poor systemic disease control. On the other hand, drug and age-related complications are assuming a prominent role in the ophthalmic care of these patients.

Choroidal thickness changes in systemic lupus erythematosus patients

Purpose

To compare choroidal thickness (CT) between patients with systemic lupus erythematosus (SLE) without ophthalmologic manifestations and a control group. To study the effects in CT of disease duration, activity index, medication and systemic comorbidities.

Methods

Cross-sectional study where spectral-domain optical coherence tomography with enhanced depth imaging was used to measure CT in 13 locations, subfoveally and at 500-µm intervals along a horizontal and a vertical section from the fovea. Linear regression models were used.

Results

Sixty-eight SLE patients and fifty healthy controls were enrolled. CT multivariable analysis revealed lower values in SLE patients (12.93-26.73 µm thinner) in all locations, except the inferior quadrants (6.48-10.44 µm thicker); however, none of these results reached statistical significance. Contrary to the control group, the normal topographic variation in CT between macular quadrants and from the center to the periphery was not observed in the SLE group. Multivariable analysis in the SLE group alone revealed a significant negative association with anticoagulants (50.10-56.09 µm thinner) and lupus nephritis (40.79-58.63 µm thinner). Contrary to controls, the CT of SLE patients did not respond to changes in mean arterial pressure.

Conclusion

CT in SLE appears to be thinner, particularly in the subset of patients with nephritis and taking anticoagulants, suggesting more advanced systemic vascular disease. Choroidal responses to hemodynamic changes may also be altered in SLE.

Late-onset Leber's hereditary optic neuropathy: the role of environmental factors in hereditary diseases

Leber's hereditary optic neuropathy (LHON) is an optic neuropathy of mitochondrial inheritance, characterised by incomplete penetrance and variable expressivity. Typically, young male patients present with sequential, severe, rapidly progressive loss of central vision, with characteristic funduscopic findings. However, LHON may present at any age, in both genders, and fundus examination may be normal. Evidence has emerged to support the role of environmental factors in triggering LHON, by disrupting the normal mechanisms of mitochondrial function. We present two clinical cases of LHON of late onset, and provide a literature review on atypical cases of LHON and the role of environmental triggers.

Rho kinase inhibitors-a review on the physiology and clinical use in Ophthalmology

The Rho kinase (ROCK) signaling pathway is involved in several cellular events that include cell proliferation and cytoskeleton modulation leading to cell adhesion. The ROCK pathway in the human eye has been hypothesized to play important roles in corneal endothelial cell physiology and pathologic states. In addition, ROCK signaling has been identified as an important regulator of trabecular meshwork (TM) outflow, which is altered in glaucomatous eyes. These roles in corneal and glaucomatous disease states have led to the growing interest in the development of drugs selectively targeting this pathway (ROCK inhibitors). The authors provide a review of the literature on the pathobiology of the ROCK signaling in corneal endothelial disease, glaucoma, and vitreoretinal disease, as well as the clinical usefulness of ROCK inhibitors in Ophthalmology.

Nanotechnology-Ocular Devices for Glaucoma Treatment: A Literature Review

Nanotechnology enabled the development of materials and devices with great utility in different fields of medicine. By using engineered-based nano-devices and structures, human biological systems may be controlled and repaired at a molecular scale, ultimately leading to a biological benefit. In particular, in the field of glaucoma treatment, nanotechnology may, for example, enhance drug residence time on the ocular surface and ocular bioavailability, as well as improve surgical success by both optimizing postoperative scarring and providing a wider safety window. Further studies are still needed to entirely explain the pharmacodynamics of nanotechnology-based therapeutic approaches and prove their biological consequences in human eyes. This review aims to summarize the literature concerning the advances in nanotechnology, specifically regarding ocular devices applied to the treatment of glaucoma.

The role of ophthalmic imaging in central nervous system degeneration in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is an autoimmune connective tissue disorder that can involve any organ system. Central nervous system involvement can be a severe life threatening complication, ultimately resulting in severe neurodegenerative changes. Magnetic resonance imaging suggests that neurodegeneration, which may have deleterious effects on brain function, may occur early in SLE and experimental models suggest that neuroprotection may be feasible and beneficial. The retina is an extension of the brain. Recent ophthalmic imaging technologies are capable of identifying early changes in retinal and choroidal morphology and circulation that may reflect CNS degeneration. However, their utility in monitoring CNS involvement in SLE has been poorly studied as these have only been performed in small cohorts, in a cross-sectional design, non-quantitatively and without correlation to disease activity. The authors aim to review the current understanding of neurodegeneration associated with SLE, with particular focus on the visual pathway. We describe the neuropathology of the visual system in SLE and the evidence for retinal and choroidal neurodegenerative and microvascular changes using optical coherence tomography technology. We aim to describe the potential role of optical imaging modalities in NPSLE diagnosis and their likely impact on the study of neuronal function.

Retinal Neurodegeneration in Diabetic Patients Without Diabetic Retinopathy

Purpose

To compare the thickness of all retinal layers between a nondiabetic group and diabetic patients without diabetic retinopathy (DR).

Methods

Cross-sectional study, in which all subjects underwent an ophthalmic examination including optical coherence tomography. After automatic retinal segmentation, each retinal layer thickness (eight separate layers and overall thickness) was calculated in all nine Early Treatment Diabetic Retinopathy Study (ETDRS) areas. The choroidal thickness (CT) also was measured at five locations. Generalized additive regression models were used to analyze the data.

Results

A total of 175 patients were recruited, 50 nondiabetic subjects and 125 diabetic patients without DR, stratified into three groups according to diabetes duration: group I (<5 years, n = 55), group II (5-10 years, n = 39), and group III (>10 years, n = 31). Overall, groups I and III of diabetic patients had a decrease in the photoreceptor layer (PR) thickness, when compared with the nondiabetic subjects in six ETDRS areas (P < 0.0007). Patients with more recent diagnosis (group I) had thinner PR than those with moderate duration (group II). Interestingly, patients with longer known disease (group III) had the thinnest PR values. There were no overall differences in the remaining retinal parameters.

Conclusions

Retinal thickness profile is not linear throughout disease duration. Even in the absence of funduscopic disease, PR layer in diabetic patients seems to differ from nondiabetic subjects, thus suggesting that some form of neurodegeneration may take place before clinical signs of vascular problems arise.

OCT in Alzheimer's disease: thinning of the RNFL and superior hemiretina

BACKGROUND

Peripapillary retinal nerve fiber layer (pRNFL) and internal macular layer thinning have been demonstrated in Alzheimer's disease (AD) with optical coherence tomography (OCT) studies. The purpose of this study is to compare the pRNFL thickness and overall retinal thickness (RT) in AD patients with non-AD patients, using spectral domain optical coherence tomography (SD-OCT) and determine the sectors most characteristically affected in AD.

METHODS

A cross-sectional study was performed to determine the pRNFL and overall macular RT thicknesses in AD and non-AD patients, attending a tertiary hospital center. For pRNFL, the global and six peripapillary quadrants were calculated, and for overall RT values, the nine Early Treatment Diabetic Retinopathy Study (ETDRS) areas were used. A multiple regression analysis was applied to assess the effects of disease, age, gender, spherical equivalent, visual acuity, intraocular pressure, axial length and blood pressure on pRNFL and overall macular RT.

RESULTS

A total of 202 subjects, including 50 eyes of 50 patients with mild AD (mean age 73.10; SD = 5.36 years) and 152 eyes of 152 patients without AD (mean age 71.03; SD = 4.62 years). After Bonferroni correction, the pRNFL was significantly thinner for the AD group globally and in the temporal superior quadrant (10.76 μm and 20.09 μm mean decrease, respectively). The RT thickness was also decreased in superior sectors S3 and S6 (mean thinning of 9.92 μm and 11.65 μm, respectively). Spearman's correlation coefficient showed a direct association between pRNFL in the temporal superior quadrant and RT in superior S6 and S3 sectors (r_S = 0.41; p < 0.001 and r_S = 0.28; p < 0.001, respectively).

CONCLUSIONS

Patients with AD showed a significant thickness reduction in global and temporal superior quadrants in pRNFL and in superior pericentral and peripheral sectors of RT. These findings may reflect a peripapillary and retinal changes characteristic of AD, suggesting the importance of SD-OCT as a potential adjuvant in early diagnosis of AD. Further studies are needed to understand which retinal layers and macular sectors are more useful as potential ocular biomarker over time in AD.

Retina and Choroid of Diabetic Patients Without Observed Retinal Vascular Changes: A Longitudinal Study

PURPOSE

To identify changes in choroidal thickness (CT) and all retinal layers of diabetic patients without diabetic retinopathy (DR) after 1 year of follow-up.

DESIGN

Prospective observational cohort study.

METHODS

Overall, 125 diabetic patients without DR were included. Two visits were scheduled: the first visit (V1) and a second visit after 12 months (V2). At both visits, patients received a complete ophthalmologic evaluation that included OCT. Each retinal layer thickness was calculated for 9 ETDRS sectors, and CT was measured at 13 locations. Generalized linear mixed-effects models were used.

RESULTS

Of the 125 patients, 103 completed the study, and 9 of the 103 developed DR (8.7%). CT was significantly higher at V2 than at V1, with an average value of 10-17 μm at almost half the locations (500, 1000, and 1500 μm temporal; 500 and 1000 μm nasal; and 1000 μm superior to the fovea) (P < .001-.003). The thicknesses of the ganglion cell layer (I3 and N6 sectors), inner plexiform layer (S6 and N6 sectors), inner nuclear layer (T6 and N6 sectors), and outer plexiform layer (S6 sector), as well as the overall retinal thickness (RT) (S3, N3, I3, S6, and T6 sectors), were decreased at V2 (P < .001). Visible retinopathy was negatively associated with overall RT (central, S3, T3, I3, and N3 sectors, P = .004-.024) and the thickness of the ONL (T6 and I6 sectors, P = .007 and P = .009) and photoreceptor layer (N6 sector, P = .038). The presence of DR decreased the overall RT by 13.04-16.63 μm.

CONCLUSIONS

Diabetic patients without DR showed a thicker choroid and a thinner retina, particularly in inner layers, after 1 year of follow-up. These structural changes may correspond to the early neurodegenerative phase of DR.

Choroidal thinning: Alzheimer's disease and aging

INTRODUCTION

The purpose of this study was to measure and to compare macular choroidal thickness (CT) between patients with mild Alzheimer's disease (AD), patients without AD, and elderly patients.

METHODS

CT was measured manually in 13 locations at 500-μm intervals of a horizontal and a vertical section from the fovea. Linear regression models were used to analyze the data.

RESULTS

Fifty patients with a diagnosis of mild AD (73.1 years), 152 patients without AD (71.03 years), and 50 elderly without AD (82.14 years) were included. In the AD patients, CT was significantly thinner in all 13 locations (P < .001-comparing with age-match group), and comparing with the elderly group, a more pronounced difference was found in two locations temporal to the fovea.

DISCUSSION

Patients with AD showed a significant choroidal thinning even when compared with elderly subjects. The reduction of CT may aid in the diagnoses of AD, probably reflecting the importance of vascular factors in their pathogenesis.

Telemedicine multimedia system to support neurodegenerative diseases participatory management

Parkinson's disease (PD) is a highly prevalent and disabling condition that requires a constant monitoring of patient's condition. Nevertheless, in Portugal appointments with specialist only occur every 6 months and the patient's capability to recall important past events is not always accurate besides often being a misinterpretation of their symptoms. In this paper we present a user-centred process for the design of a multimedia platform for the self-management of PD.

Alzheimer's disease: A review of its visual system neuropathology. Optical coherence tomography-a potential role as a study tool in vivo

Alzheimer's disease (AD) is a prevalent, long-term progressive degenerative disorder with great social impact. It is currently thought that, in addition to neurodegeneration, vascular changes also play a role in the pathophysiology of the disease. Visual symptoms are frequent and are an early clinical manifestation; a number of psychophysiologic changes occur in visual function, including visual field defects, abnormal contrast sensitivity, abnormalities in color vision, depth perception deficits, and motion detection abnormalities. These visual changes were initially believed to be solely due to neurodegeneration in the posterior visual pathway. However, evidence from pathology studies in both animal models of AD and humans has demonstrated that neurodegeneration also takes place in the anterior visual pathway, with involvement of the retinal ganglion cells' (RGCs) dendrites, somata, and axons in the optic nerve. These studies additionally showed that patients with AD have changes in retinal and choroidal microvasculature. Pathology findings have been corroborated in in-vivo assessment of the retina and optic nerve head (ONH), as well as the retinal and choroidal vasculature. Optical coherence tomography (OCT) in particular has shown great utility in the assessment of these changes, and it may become a useful tool for early detection and monitoring disease progression in AD. The authors make a review of the current understanding of retinal and choroidal pathological changes in patients with AD, with particular focus on in-vivo evidence of retinal and choroidal neurodegenerative and microvascular changes using OCT technology.

Diabetic choroidopathy: a review of the current literature

Diabetic retinopathy is an increasingly prevalent disease, and a leading contributor to the burden of all-cause blindness worldwide. In addition to retinal changes, choroidal abnormalities are common in patients with diabetes. The first studies concerning this vascular structure were based on histologic, indocyanine angiography and laser Doppler flowmetry techniques, but the development of new optical coherence tomography (OCT) technologies and imaging software for enhanced depth imaging (EDI)-OCT in recent years has made it possible to provide more detailed images of the choroidal anatomy and topography.In diabetic patients, several choroidal changes have been described in the literature throughout the years; the recent focus is choroidal thickness, which is significantly different from that in healthy patients. However, understanding choroidal manifestations of diabetic eye disease remains a real challenge, and this gap is hindering efforts towards better defining choroidal evaluation as a predictive factor for disease evolution and treatment response.This review aims to summarize the recent literature concerning changes in choroidal structure in diabetic patients, the relationship to diabetic retinal disease progression, and finally, the current and potential application of the measurement of variations in choroidal thickness for patient management.

Diabetes Mellitus as a Risk Factor in Glaucoma's Physiopathology and Surgical Survival Time: A Literature Review

Glaucoma is a multifactorial condition under serious influence of many risk factors. The role of diabetes mellitus (DM) in glaucoma etiology or progression remains inconclusive. Although, the diabetic patients have different healing mechanism comparing to the general population and it has a possible-negative role on surgical outcomes. This review article attempts to analyze the association of both diseases, glaucoma and DM, before and after the surgery. The epidemiological studies, based mainly in population prevalence analyzes, have shown opposite outcomes in time and even in the most recent articles also the association remains inconclusive. On the contrary, the experimental models based on animal induced chronic hyperglycemia have shown an important association of both diseases, explained by common neurodegenerative mechanisms. Diabetic patients have a different wound healing process in the eye viz-a-viz other organs. The healing process is more and it results in lower surgical survival time, higher intraocular pressure (IOP) levels and, therefore, these patients usually need more medication to lower the IOP. Both randomized and nonrandomized retrospective and experimental molecular studies have shown the association between DM and glaucoma. Further studies are needed to get better explanations about outcomes on more recent surgical procedures and with the exponential use of antifibrotics. How to cite this article: Costa L, Cunha JP, Amado D, Pinto LA, Ferreira J. Diabetes Mellitus as a Risk Factor in Glaucoma's Physiopathology and Surgical Survival Time: A Literature Review. J Curr Glaucoma Pract 2015;9(3):81-85.

Macular Ganglion Cell Layer and Peripapillary Retinal Nerve Fibre Layer Thickness in Patients with Unilateral Posterior Cerebral Artery Ischaemic Lesion: An Optical Coherence Tomography Study

The purpose of this study is to evaluate the macular ganglion cell layer (GCL) and peripapillary retinal nerve fibre layer (RNFL) thickness in patients with unilateral posterior cerebral artery (PCA) ischaemic lesions using spectral-domain optical coherence tomography (SD-OCT). A prospective, case-control study of patients with unilateral PCA lesion was conducted in the neuro-ophthalmology clinic of Centro Hospitalar Lisboa Central. Macular and peripapillary SD-OCT scans were performed in both eyes of each patient. Twelve patients with PCA lesions (stroke group) and 12 healthy normal controls were included in this study. Peripapillary RNFL comparison between both eyes of the same subject in the stroke group found a thinning in the superior-temporal (p = 0.008) and inferior-temporal (p = 0.023) sectors of the ipsilateral eye and nasal sector (p = 0.003) of the contralateral eye. Macular GCL thickness comparison showed a reduction temporally in the ipsilateral eye (p = 0.004) and nasally in the contralateral eye (p = 0.002). Peripapillary RNFL thickness was significantly reduced in both eyes of patients with PCA compared with controls, affecting all sectors in the contralateral eye and predominantly temporal sectors in the ipsilateral eye. A statistically significant decrease in macular GCL thickness was found in both hemiretinas of both eyes of stroke patients when compared with controls (p < 0.05). This study shows that TRD may play a role in the physiopathology of lesions of the posterior visual pathway.

Wrist rigidity assessment during Deep Brain Stimulation surgery

Parkinson's Disease (PD) patients often need Deep Brain Stimulation (DBS) surgery when they become intolerant to drugs or these lose efficiency. A stimulation electrode is implanted in the basal ganglia to promote the functional control of the deregulated dopaminergic motor pathways. The stimulation target is defined by medical imaging, followed by electrophysiological inspection for fine electrode position trimming and electrical stimulation tuning. Intra-operative stimulation of the target and the evaluation of wrist rigidity allows to choose the stimulation parameters which best alleviate PD symptoms without side effects. Neurologists impose a passive wrist flexion movement and qualitatively describe the perceived decrease in rigidity under different voltages, based on its experience and with subjectivity. We designed a novel, comfortable and wireless wearable motion sensor to classify the wrist rigidity by deriving a robust signal descriptor from angular speed values and a polynomial mathematical model to classify signals using a quantitative continuous scale. The descriptor significantly (p<0.05) distinguished between non-rigid and rigid states, and the classification model labelled correctly 83.9% of the evaluated signals against the blind-agreement of two specialists. Additionally, we developed a methodology to detect cogwheel rigidity from the angular speed signal with high sensitivity (0.93). Our system provides a reliable evaluation of wrist rigidity, improving upon the inherent subjective clinical evaluation while using small, simple and easy to use motion sensor.

Choroidal Thickness in Nonarteritic Anterior Ischaemic Optic Neuropathy: A Study with Optical Coherence Tomography

Nonarteritic anterior ischemic optic neuropathy (NA-AION) is the most common nonglaucomatous optic neuropathy in adults over 50 years of age. It is usually related to cardiovascular risk factors. The primary objective of this study was to evaluate choroidal thickness in patients with chronic NA-AION, and the secondary objective was to evaluate macular thickness in these patients. This cross-sectional study compared two groups: group 1 included 20 eyes of 20 patients with chronic NA-AION, and group 2 included 31 eyes of 31 healthy controls. In both groups, the choroidal thickness was measured using the enhanced depth imaging program of Heidelberg Spectralis® optical coherence tomography (Heidelberg Engineering, Heidelberg, Germany). The macular thickness was also measured using the automatic software of the same device. The mean follow-up time after NA-AION in group 1 was 57.17 ± 26.92 months. The mean choroidal thickness of the posterior pole was 244.38 ± 61.03 µm in group 1 and 214.18 ± 65.97 µm in group 2 (p = 0.004). The mean macular thickness was higher in group 2. Macular thickness is reduced in eyes that had an episode of NA-AION, whereas choroidal thickness is generally higher in these eyes when compared with normal eyes. The increase in choroidal thickness may be due to a local dysfunction in vascular autoregulatory mechanisms, which may predispose to ischemic phenomena.

Connectivity patterns of pallidal DBS electrodes in focal dystonia: a diffusion tensor tractography study

Deep brain stimulation (DBS) of the internal pallidal segment (GPi: globus pallidus internus) is gold standard treatment for medically intractable dystonia, but detailed knowledge of mechanisms of action is still not available. There is evidence that stimulation of ventral and dorsal GPi produces opposite motor effects. The aim of this study was to analyse connectivity profiles of ventral and dorsal GPi. Probabilistic tractography was initiated from DBS electrode contacts in 8 patients with focal dystonia and connectivity patterns compared. We found a considerable difference in anterior-posterior distribution of fibres along the mesial cortical sensorimotor areas between the ventral and dorsal GPi connectivity. This finding of distinct GPi connectivity profiles further confirms the clinical evidence that the ventral and dorsal GPi belong to different functional and anatomic motor subsystems. Their involvement could play an important role in promoting clinical DBS effects in dystonia.

Intraorbital abducens nerve schwannoma

BACKGROUND

Schwannomas of the abducens nerve are extremely rare tumors. The tumor may be located within the cavernous sinus or more often at the prepontine region. However, literature research has identified only one case of isolated schwannoma of the orbit, arising from the terminal branches of the abducens nerve to the lateral rectus muscle. This is only the second report of an abducens nerve schwannoma located entirely intraconal.

CASE DESCRIPTION

We report a case of an intraorbital abducens nerve schwannoma in a 42-year-old man with no signs of neurofibromatosis. The lesion resulted in progressive diplopia and focal abducens palsy. The clinical, radiologic, and pathologic features are presented.

RESULTS

We point the particular aspects and discuss the possible treatments and approaches to preserve nerve function.

CONCLUSIONS

Being a benign lesion, one of the goals has always been total removal. The knowledge of the correct anatomic features made us believe that the VI nerve function could be preserved. Our case is the first example of a total removal with eye abduction preserved. Because of that, we believe that it is reasonable to aim for these goals in future cases.

A new and fast nonlinear method for association analysis of biosignals

In this paper, we present some original theoretical aspects of a fast nonlinear association measure based on the work of Cramér. The features of this new measure--the V measure--when applied to biosignals are also shown using simulated time series. A comparative study with other well-known association measures available in the literature of biosignals is presented. V was found to be twice as fast and more robust to nonlinearities than the classical cross-correlation ratio (r2) and more than 100 times faster than the nonlinear regression coefficient (h2), presenting similar behavior in the presence of nonlinear simulated situations. This new measure is very fast and versatile. It is appropriate to deal with nonlinear relations presenting usually a sharp peak in the association function enabling a high degree of selectivity for maxima detection. It seems to constitute an improvement over linear methods of association which is faster and more robust to the existing nonlinearities. It can be used as an alternative to more complex nonlinear association measures when computational speed is an important feature.

SIGIF: a digital signal interchange format with application in neurophysiology

In this paper, the authors describe a biomedical digital-signal interchange format. The format supports both raw and processed data, multiple segments, several signal structures and representations, and an open architecture. Its versatility and adaptability allows the software to take advantage of any particular features of the acquisition hardware. The format has been used and improved in routine work during a five-year period involving the cooperation between two hospitals and one engineering research center. In order to support the format, an object oriented C language library has been developed and is also shortly described.

Scalp EEG recording: interictal/ictal location and spreading of epileptiform events

The relevance of scalp EEG recording on the selection of patients for epilepsy surgery usually is based on the concordance between the location of the epileptogenic focus and the presumed ictal origin of clinical seizures visually identified or video recorded. Bilateralisation and/or spreading of the epileptiform events are among the causes of the relative lack of agreement between scalp topography and origin of EEG potentials. Computer methods mainly if they are adaptive and use multistrategic approaches improve the accuracy on the detection of the epileptogenic focus, extracting relevant information on the location and spreading of epileptiform events.

The role of computer based techniques in patient monitoring: technical note

In this paper the requirements of Neurophysiology and Neurotraumatology monitoring are analyzed. As a result a set of designated systems were developed by the authors a short description of which is given in the paper. Finally the future perspectives and problems to be faced are briefly described.