A traffic perimetry test that adheres to the European visual field requirements

PURPOSE

European visual requirements for driving generally follow the standards of the European Union (EU), but the lack of a uniform perimetry algorithm leads to differing practices in enforcing visual field regulations. The purpose of this study was to develop a perimetry algorithm for group 1 driving licenses (car and motorcycle) that adheres to the European requirements.

METHODS

We determined the features of a traffic perimetry algorithm complying with the EU directive 2009/113/EC and the underlying scientific report by the Eyesight Working Group. The final algorithm was a binocular, supra-threshold test with 37 central and 86 peripheral test points within 140º x 40º. It was created as a custom test for an Octopus 900 perimeter and tested on participants with known visual field defects. Findings were compared with the Esterman program in reference to British and Norwegian regulations, which both recommend the Esterman program for assessing fitness to drive but differ in definition of negative and positive results.

RESULTS

Twenty-five participants were examined. In comparison with the traffic perimetry algorithm, sensitivity and specificity of the British regulations were 0.78 (95% confidence interval (CI) 0.40-0.97) and 1.00 (95% CI 0.79-1.00). Similarly, sensitivity and specificity of the Norwegian regulations were 0.89 (95% CI 0.52-1.00) and 0.81 (95% CI 0.54-0.96).

CONCLUSION

The lack of a perimetry algorithm that conforms to the scientific recommendations challenges the fundamental right of European drivers for legal equality. This study demonstrates a binocular supra-threshold test that adheres to the European visual field requirements for group 1 driving licenses.

Bilateral calcification of the optic nerve sheath: A diagnostic dilemma

Purpose

To present a case of symptomatic optic nerve sheath calcification and highlight clues and pitfalls for the final diagnosis: bilateral optic nerve sheath meningioma.

Observations

A 48-year-old man presented with painless vision loss in his left eye and findings consistent with left optic nerve atrophy. Magnetic resonance imaging (MRI) displayed thinning of the left optic nerve without contrast-enhancement or evidence of compressive lesions. A supplementary computed tomography angiography (CTA) exposed scattered dural calcification, which included the optic nerves. This was regarded as an incidental finding. The initial diagnosis was ischemic optic neuropathy. Over the next two years, the vision loss in the left eye progressed. A CT of the orbits revealed extensive calcification surrounding both optic nerves. A second MRI was unchanged in comparison to the first MRI. The diagnosis was changed to idiopathic duro-optic calcification. The vision in the left eye further declined over another two years. Consecutive optical coherence tomography measurements of the peripapillary retinal nerve fiber layer suggested bilateral progressive thinning. A third MRI displayed progression of tubular contrast-enhancement surrounding the optic nerves. On the basis of this finding, the patient was finally diagnosed with a bilateral optic nerve sheath meningioma and received external beam radiotherapy.

Conclusion and importance

It is crucial to differentiate an optic nerve sheath meningioma from idiopathic calcification of the optic nerve. In the present case the initial MRI did not detect optic nerve sheath abnormalities. To better demonstrate characteristic calcification, additional CT imaging should be considered when a bilateral optic nerve sheath meningioma is suspected.

Transient smartphone blindness

BACKGROUND

The aetiology of transient monocular vision loss is not necessarily thromboembolic, and careful history-taking is crucial in making the correct diagnosis.

CASE PRESENTATION

A previously healthy woman in her thirties was referred to our outpatient stroke clinic on suspicion of recurring amaurosis fugax in her right eye. The ophthalmic and neurologic examinations were normal. A review of the medical history revealed that her symptoms occurred in connection with using her smartphone in bed, typically while lying on her left side with the left eye covered by the pillow. When standing up from the bed again with the lights turned off in the bedroom, she noticed vision loss in her right eye.

INTERPRETATION

We concluded that the patient had experienced transient smartphone blindness. This phenomenon can occur when monocularly using a smartphone under scotopic lighting conditions; only the occluded eye adapts to darkness, and the other eye is perceived to be blind if looking away from the bright smartphone screen.

Thirteen years of intravitreal anti-vascular endothelial growth factor therapy: the promises and burdens of a paradigm shift told from the perspective of the largest retina service in Norway

PURPOSE

To describe the first 13 years of anti-vascular endothelial growth factor (anti-VEGF) therapy from the perspective of a public ophthalmic department serving a local community of almost one million people.

METHODS

Retrospective registry study. Data from Oslo University Hospital, Norway were collected from 2006 through 2018. Hospital episode statistics were searched for episodes of care encompassing intravitreal anti-VEGF procedures. Patient-specific ID numbers, diagnoses, and drug codes were registered. In general, bevacizumab was used as first-line treatment, with aflibercept reserved for resistant cases from 2013.

RESULTS

The number of unique patients treated per year increased from 130 in 2006 to 3428 in 2018. In 2018, 2488 (73%) patients had also received treatment the previous year. The number of yearly injections increased from 228 in 2006 to 25 570 in 2018. In 2018 the diagnosis macular degeneration constituted 69% of injections, diabetic retinopathy constituted 15%, retinal vein occlusion constituted 13%, and other diagnoses constituted 3%. In the same year 49% of injections were with bevacizumab, 46% with aflibercept, 4% with ranibizumab, and 1% with dexamethasone implants. The bevacizumab to aflibercept ratio was almost 1:1 for macular degeneration and diabetic retinopathy; for retinal vein occlusion the ratio was 13:7.

CONCLUSION

In 13 years there was an approximately 100-fold increase in the number of yearly intravitreal injections. A majority of patients received long-term treatment. Macular degeneration was the most common diagnosis. Using bevacizumab as first-line treatment, with aflibercept reserved for resistant cases from 2013, eventually resulted in a nearly 1:1 ratio in drug usage.

In Vivo Evidence for Impaired Glymphatic Function in the Visual Pathway of Patients With Normal Pressure Hydrocephalus

Purpose

Impaired ability to remove toxic metabolites from central nervous system may be an important link between cerebral and ophthalmic degenerative diseases. The aim of the present study was to compare the glymphatic function in the visual pathway in patients with idiopathic normal pressure hydrocephalus (iNPH), a neurodegenerative dementia subtype, with a reference group.

Methods

We compared 31 subjects with Definite iNPH (i.e., shunt-responsive) with 13 references in a prospective and observational study. After intrathecal injection of the magnetic contrast agent gadobutrol (Gadovist, 0.5 mL, 1.0 mmol/mL, Bayer Pharma AG), serving as a tracer, consecutive magnetic resonance imaging (MRI) scans were obtained (next 24-48 hours). The normalized MRI T1 signal recorded in the cerebrospinal fluid (CSF) and along the visual pathway served as a semi-quantitative measure of tracer enrichment. Gadobutrol does not penetrate the blood-brain barrier and is thus confined to the extravascular space. Overnight measurements of pulsatile intracranial pressure were used as a surrogate marker for the intracranial compliance.

Results

The tracer enriched the prechiasmatic cistern similarly in both groups, but clearance was delayed in the iNPH group. Moreover, both delayed enrichment and clearance of the tracer were observed in the visual pathway in the iNPH subjects. The enrichment in the visual pathway and the CSF correlated. Individuals with elevated pulsatile intracranial pressure showed reduced enrichment within the visual pathway.

Conclusions

There was delayed enrichment and clearance of a tracer in the visual pathway of iNPH patients, which suggests impaired glymphatic function in the visual pathway in this disease.

Unilateral acute anterior uveitis is associated with ipsilateral changes in the tear fluid proteome that involves the LXR/RXR pathway

PURPOSE

To determine whether unilateral acute anterior uveitis (AAU) induces ipsilateral changes in the tear fluid proteome.

METHODS

Five patients (25-77 years old) with unilateral AAU were included. Tear fluid samples were obtained using Schirmer's test strips. The healthy eye served as control. Proteins were identified by liquid chromatography tandem mass spectrometry.

RESULTS

Two hundred forty-two tear fluid sample proteins were identified, of which 75 were present in at least three patients. Nine proteins were at least 1.5-fold increased, whereas eight were at least 1.5-fold decreased in tears from the diseased eye compared with the healthy eye. APOBEC3A was significantly increased (1.43-fold; P = 0.04), whereas TGM2 was significantly decreased (- 1.21-fold; P = 0.03) in tears from the diseased eye relative to the healthy eye. Ingenuity Pathway Analysis identified LXR/RXR (P < 1.02E-4) as a top canonical pathway.

CONCLUSION

Unilateral AAU induced detectable changes in the ipsilateral tear fluid proteome and involvement of the inflammation-associated LXR/RXR pathway.

Intravitreal therapy for retinal diseases in Norway 2011-2015

PURPOSE

During the past decade, intravitreally administered biologic drugs have advanced the treatment of retinal diseases, such as wet age-related macular degeneration (AMD), diabetic macular oedema and retinal venous occlusions. The drugs as well as the necessary disease management imply considerable economic burden on healthcare systems. This Norwegian study documents the rates of use of intravitreal therapies and intercounty variation over a 5-year period.

METHODS

We collected data from the Norwegian Patient Register for all episodes of care encompassing intravitreal therapy during the period 2011-2015. For each episode, we received information on patient age, sex, county of residence, diagnosis and name of drug injected.

RESULTS

During the study period, 21 277 patients had in total 236 857 episodes of care. The number of intravitreal injections doubled from 2011 to 2015, reaching 63 601 injections in 2015, of which 77% were for diagnosed wet AMD. In 2015, the age-adjusted number of episodes varied from 19 to 55 per 1000 population aged 50+ across Norway's 19 counties. The age-adjusted number of patients treated per 1000 population aged 50+ varied from 5.22 to 8.35.

CONCLUSION

The use of intravitreal injections increased rapidly with wet AMD as the most frequent diagnosis and with varying utilization across Norway's 19 counties. The causes of the varying use of intravitreal therapies could not be established but may reflect variation in disease prevalence, treatment capacity, travel distance to the nearest ophthalmic service and lack of national treatment guidelines. The geographic variation in utilization may challenge policy goals of equitable care and warrants further studies.

Multiple Vitelliform Lesions as a Retinal Manifestation of Alport Syndrome

Alport syndrome is associated with various ocular phenotypic features, including several retinal manifestations. The purpose of this case report was to describe a case of multiple vitelliform lesions in Alport syndrome. This particular finding has, to our knowledge, not been reported previously. A 63-year-old man with known Alport syndrome presented with symptomatic, bilateral anterior lenticonus. Fundoscopic examination revealed multiple vitelliform lesions, which were symmetrically distributed at the posterior poles. Additional retinal findings included an irregular foveal contour and central macular thinning in both eyes, as well as a multilayered retinoschisis in the left eye. The underlying pathophysiology of the vitelliform lesions may be a dysfunctional Bruch's membrane.

Off-label use of bevacizumab for wet age-related macular degeneration in Europe

PURPOSE

To analyse current off-label use of bevacizumab for wet age-related macular degeneration (AMD) in Europe.

METHODS

The study was conducted as a combined survey and literature review. It included the 22 most populous countries in Europe. In each country, ophthalmologists with particular knowledge about off-label treatment responded to a questionnaire.

RESULTS

Answers were obtained from twenty European countries. The off-label use of bevacizumab for wet AMD greatly differed between nations; the bevacizumab proportion varied from non-existent (0%) to very high (97%). There were also large disparities within single countries (e.g. 0-80%), which were attributable to differences in regional decision-making. Both governmental institutions and national ophthalmological societies expressed highly diverging opinions on the use of off-label treatment. Intravitreal administration of bevacizumab had been a matter of legal dispute in several countries. The question about responsibility for off-label therapy mainly remained unanswered.

CONCLUSIONS

There was a highly varying utilization of bevacizumab between European countries. Despite an intention of a consistent approach to medical regulations, Europe has not yet reached a professional or political consensus on the ophthalmic off-label use of bevacizumab.

The Human Visual Pathway Communicates Directly With the Subarachnoid Space

Purpose

Explore in vivo whether there is direct communication between the cerebrospinal fluid (CSF) and extravascular compartment of human visual pathway structures.

Methods

A prospective and observational study included 10 subjects who underwent intrathecal gadolinium-enhanced magnetic resonance imaging (MRI) for suspected CSF circulation disorder, but with a negative result and with no known ophthalmic diseases. After precontrast T1-weighted MRI, 0.5 mL of gadobutrol (Gadovist, 1.0 mmol/mL) was injected intrathecally. Gadobutrol distributes in the extravascular space, and served as a CSF tracer. Consecutive MRI scans were obtained throughout 24 to 48 hours. To assess gadobutrol contrast enrichment, regions of interest (ROIs) were placed at multiple locations along the visual pathway, from the primary visual cortex to the eye's vitreous body. CSF tracer dependent T1 signal was measured in each ROI. A linear mixed-model was used for statistical analyses.

Results

CSF tracer enrichment was found within the optic nerve, optic chiasm, optic tract, and primary visual cortex (P < 0.001). Peak tracer enrichment in the visual pathway generally occurred after 24 hours and was preceded by peak enhancement in the prechiasmatic cistern after 4 to 6 hours.

Conclusions

The results indicate direct communication between CSF of subarachnoid space and the extravascular space of the human visual pathway. Extravascular entry of the CSF tracer is a prerequisite for a glymphatic system, the present findings may suggest its presence. The existence of a glymphatic system in the human visual pathway could bring novel perspectives on the pathophysiology and treatment of ophthalmic diseases.

Patient-reported outcome measures in the management of neovascular age-related macular degeneration: a 1-year prospective study

Objective

To prospectively explore the following patient-reported outcome measures (PROMs) in the management of neovascular age-related macular degeneration (nAMD): (1) self-reported visual function, (2) symptom-state, (3) general-health and (4) satisfaction of treatment.

Methods and analysis

Corresponding to the four PROMs, participants responded to the following questionnaires: (1) National Eye Institute Visual-Functioning-Questionnaire (NEI-VFQ-25), (2) Patient-Acceptable-Symptom-Status (PASS 5), (3) EuroQol-Group-Questionnaire (EQ-5D-3L) and (4) Dimensions of Importance in Treatment of nAMD (DITAMD). Data were collected at baseline and after 3, 6 and 12 months of intravitreal antivascular endothelial growth factor treatment. Results were evaluated with t-tests and mixed linear regression analyses.

Results

The study included 197 patients. At baseline NEI-VFQ-25 (79.53±14.52) and EQ-5D (0.74±0.28) had relatively high scores, whereas PASS 5 was below 'acceptable' (3.30±0.80). At 12 months NEI-VFQ-25 and PASS 5 showed significant improvement, whereas EQ-5D and DITAMD remained unchanged. At baseline patients receiving treatment of the better-seeing eye (BSE) (n=52) reported significantly worse NEI-VFQ-25 and PASS 5 than patients for whom treatment only involved the worse-seeing eye (WSE), (n=145). In contrast to BSE patients, there was no improvement of NEI-VFQ-25 for WSE patients at 12 months, despite a significant improvement in best-corrected visual acuity (BCVA). Two independent variables, treatment including the BSE and BCVA for the treated eye, were found to predict both NEI-VFQ-25 and PASS 5.

Conclusion

After 12 months of nAMD treatment, there was a significant improvement in PASS 5 and NEI-VFQ-25, the latter depending on whether therapy included BSE. EQ-5D and DITAMD remained unaltered.

Endophthalmitis in Oslo, Norway

PURPOSE

To study the incidence, aetiology, pathogenic causes, treatment and visual outcomes of endophthalmitis (EO) at the Department of Ophthalmology, Oslo University Hospital (OUS), Norway.

METHODS

Retrospective registry study. Medical records of all EO patients treated at OUS over a 2-year period were reviewed.

RESULTS

The study identified 46 EO eyes of 44 patients; 19 eyes had postcataract surgery EO (PCE), and 6 eyes had postinjection EO (PIE). Of 4778 primary cataract surgeries performed at OUS, there was one PCE (incidence 0.21 per 1000; 95% CI 0.04-1.19 per 1000). Of 38 134 intravitreal injections performed at OUS, there were 3 PIE (incidence 0.08 per 1000; 95% CI 0.03-0.23 per 1000). Among 15 751 cataract surgeries performed at other ophthalmic centres in Oslo and Akershus County (OOC), there were 15 PCE (incidence 0.95 per 1000; 95% CI 0.58-1.57 per 1000). Of 3000 intravitreal injections performed at OOC, there was one PIE (incidence 0.33 per 1000; 95% CI 0.059-1.89 per 1000). For neither PCE nor PIE, there were significant differences in odds ratios between OUS and OOC. The odds ratio for PCE versus PIE was, however, 8.0 (95% CI 2.7-24.0; p < 0.001). Cultures were positive in 35 of 46 eyes (76%). The most common pathogen was Staphylococcus epidermidis. Twenty-two eyes (48%) achieved a clinically significant improvement in visual function (≥0.3 logMAR) following treatment.

CONCLUSION

The overall risk of PCE and PIE was low. It was, however, higher for PCE than PIE, probably reflecting the relative difference in invasiveness between the procedures.

Loss of horizontal macular ganglion cell complex asymmetry: an optical coherence tomography indicator of chiasmal compression

Objective

To estimate the macular ganglion cell complex (GCC) asymmetry in patients with suprasellar tumours, to compare its diagnostic performance to the nasal GCC thickness and visual field (VF) and to investigate how the parameters correlate with magnetic resonance imaging (MRI) findings.

Methods and analysis

Cross-sectional study of patients with suprasellar tumours affecting the optic chiasm. Macular optical coherence tomography (OCT) scans were evaluated for nasal GCC sector thinning and loss of normal GCC asymmetry between corresponding nasal-temporal sectors. Equivalently, VFs were analysed for defects compatible with chiasm dysfunction. The relationship between optic chiasm and tumour was measured on MRI.

Results

Thirty-three eyes of 33 patients were included. There were OCT findings in 14 eyes. Nasal GCC thinning was found in 9 eyes and loss of GCC asymmetry in 12 eyes; the two parameters were not significantly different with respect to number of positive findings (p=0.45). Loss of GCC asymmetry, however, occurred in 5 eyes among 24 without GCC thinning (proportion 0.21; 95% confidence interval 0.071 to 0.42). In 8 eyes, VF indicated pathology; of these, 7 had concurring OCT findings. The prevalence of OCT and VF findings increased significantly with suprasellar tumour extension on MRI.

Conclusion

The diagnostic capabilities of nasal GCC thinning and loss of GCC asymmetry were comparable, whilst their complementary performances increased the proportion of eyes in which OCT suggested compression. The prevalence of both OCT and VF findings grew with suprasellar tumour extension. In several cases, however, structural findings on OCT preceded detectable VF deficits.

Two-year functional and anatomical results after converting treatment resistant eyes with exudative age-related macular degeneration to aflibercept in accordance with a treat and extend protocol

PURPOSE

To study the effects of converting to aflibercept in accordance with a treat and extend (T&E) strategy in eyes with treatment resistant exudative age-related macular degeneration (AMD).

METHODS

Two-year prospective study of eyes with exudative AMD and persistent macular fluid despite monthly treatment with ranibizumab or bevacizumab. Eyes were converted to 2.0 mg aflibercept in accordance with a T&E protocol.

RESULTS

Fifty eyes from 47 patients were included. At baseline, the mean central retinal thickness (CRT) was 273 μm and mean best-corrected visual acuity (BCVA) 0.25 logarithm of the minimal angle of resolution (logMAR). The mean number of aflibercept injections the first year was 9.2. After 1 year, there was a reduction in mean CRT to 228 μm (p < 0.001); 22 eyes (44%) had a dry macula; and the mean BCVA was 0.24 logMAR (p = 0.531). The mean number of aflibercept injections the second year was 8.0 (p = 0.013 compared to first year). After 2 years, 24 eyes (48%) received treatment more frequently than every eighth week. The mean CRT was 225 μm (p < 0.001 compared to baseline); 31 eyes (62%) had a dry macula; and mean BCVA was 0.32 logMAR (p = 0.005 compared to baseline). Five eyes did not complete 2 years of aflibercept treatment after failing to improve.

CONCLUSION

A majority of eyes showed improved anatomic outcomes. There was a small decrease in mean BCVA after the second year of treatment. About half of the eyes required treatment more frequently than the recommended aflibercept label of an 8-week interval.