Detection of capillary abnormalities in early diabetic retinopathy using scanning laser ophthalmoscopy and optical coherence tomography combined with adaptive optics.

This study tested if a high-resolution, multi-modal, multi-scale retinal imaging instrument can provide novel information about structural abnormalities in vivo. The study examined 11 patients with very mild to moderate non-proliferative diabetic retinopathy (NPDR) and 10 healthy subjects using fundus photography, optical coherence tomography (OCT), OCT angiography (OCTA), adaptive optics scanning laser ophthalmoscopy (AO-SLO), adaptive optics OCT and OCTA (AO-OCT(A)). Of 21 eyes of 11 patients, 11 had very mild NPDR, 8 had mild NPDR, 2 had moderate NPDR, and 1 had no retinopathy. Using AO-SLO, capillary looping, inflections and dilations were detected in 8 patients with very mild or mild NPDR, and microaneurysms containing hyperreflective granular elements were visible in 9 patients with mild or moderate NPDR. Most of the abnormalities were seen to be perfused in the corresponding OCTA scans while a few capillary loops appeared to be occluded or perfused at a non-detectable flow rate, possibly because of hypoperfusion. In one patient with moderate NPDR, non-perfused capillaries, also called ghost vessels, were identified by alignment of corresponding en face AO-OCT and AO-OCTA images. The combination of multiple non-invasive imaging methods could identify prominent microscopic abnormalities in diabetic retinopathy earlier and more detailed than conventional fundus imaging devices.

Validation of retinal oximetry vessel selection using fluorescein angiography in patients with optic disc drusen.

Retinal oximetry could provide insights into the pathophysiology of optic nerve disease, including optic disc drusen (ODD). Vessel selection for oximetry analysis is based on morphological characteristics of arterioles and venules and supported by an overlay of estimated blood oxygen saturations. The purpose of this cross-sectional study was to determine the validity of this vessel selection procedure by comparing it with vessel selection supported by video fluorescein angiography (FA). The study included 36 eyes of 36 patients with ODD who underwent retinal oximetry (Oxymap retinal oximeter T1) followed by FA (Heidelberg Spectralis). Two trained graders selected vessel segments in a pre-defined measurement area around the optic disc. One of these graders additionally performed the vessel segment selection with the support of FA images. When performed by the same grader, FA-supported and non-FA-supported vessel selection did not lead to significant differences in total vessel segment length, estimated oxygen saturations or vessel diameters (all p > 0.05). Inter-grader differences were found for arterial and venous segment lengths and arterial saturation (p < 0.05). A similar tendency was found for the arteriovenous saturation difference (p = 0.10). In conclusion, identifying vessel segments for retinal oximetry analysis based on vessel morphology and supported by a color-coded saturation overlay appears to be a valid method without the need for invasive angiography. A numerically small inter-grader variation may influence oximetry results. Further studies of retinal oximetry in ODD are warranted.

Short-term outcomes of treatment switch to faricimab in patients with aflibercept-resistant neovascular age-related macular degeneration.

PURPOSE: To report short-term outcomes of treatment switch to faricimab in real-world patients with aflibercept-resistant neovascular age-related macular degeneration (AMD). METHODS: Single-center, retrospective cohort study with chart-review using electronic injection database, electronic medical records, and optical coherence tomography (OCT) data from May to September 2023. RESULTS: A total of 50 eyes of 46 patients were analyzed. Faricimab treatment led to absence of fluid in 32% of the eyes and a reduction of fluid in 84% of the eyes. There was a statistically significant decrease in central retinal thickness (CRT) and pigment epithelial detachment (PED) height in those that responded to the switch (median difference: - 31 µm, IQR: 55, p < 0.0001 and median difference: - 21 µm, IQR: 36, p < 0.0001, respectively) and a statistically significant increase in CRT (median difference: + 19 µm, IQR: 20, p = 0.0143) and no change in PED height (median difference: + 22 µm, IQR: 64, p = 0.1508) in those that did not. Best-corrected visual acuity (BCVA) showed marginal decrease with low statistical significance. No ocular or systemic safety events were observed. CONCLUSIONS: Our findings suggest that switching to faricimab is generally safe and effective in patients with neovascular AMD who are otherwise difficult to treat and have residual fluid despite frequent injections with aflibercept. We observed a high rate of morphological response to the treatment switch, improvement of anatomical parameters with about one-third of patients having dry macula following a single injection, and a marginal change in BCVA. Sustainability of these results requires further investigation. STUDY REGISTRATION: ClinicalTrials.gov registration number: NCT06124677. Date of registration: 09/11/2023, retrospectively registered.

Endophthalmitis following same-day bilateral anti-VEGF injections: a systematic review.

PURPOSE: To review the risk of endophthalmitis in same-day bilateral anti-VEGF injections. METHODS: We searched 12 literature databases for studies on the risk of endophthalmitis after same-day bilateral intravitreal anti-VEGF injections. Data extraction was made independently by two authors and discussed afterward until reaching consensus. RESULTS: Seventeen studies were included with a total of 138,478 intravitreal anti-VEGF injections (69,239 bilateral injections sessions) given in at least 7579 patients. In total, 33 cases of endophthalmitis had occurred, and no cases were bilateral. The incidence of endophthalmitis ranged from 0 to 0.53% per intravitreal injection across studies. CONCLUSIONS: We suggest that clinicians can consider same-day treatment of both eyes of patients in need of bilateral intravitreal anti-VEGF injection therapy, but larger studies are needed to quantify the exact risk of endophthalmitis.

Systemic adverse events and all-cause mortality following same-session bilateral intravitreal anti-VEGF injections: a systematic review.

PURPOSE: To review the risk of systemic adverse events and all-cause mortality following same-day bilateral anti-VEGF injections. METHODS: Twelve literature databases were searched for studies on same-session bilateral intravitreal anti-VEGF injections. Studies reporting on systemic adverse events and mortality were included. Data extraction was made independently by two authors and discussed afterwards until consensus was reached. RESULTS: Seven studies were included with a total of 13,406 intravitreal anti-VEGF injections (6703 bilateral injections sessions) given to 689 patients. Across all studies, mean age of patients ranged from 55.7 to 82.5 years, and mean follow-up times ranged from 1.3 to 41 months. Six studies reported on systemic adverse events: Two cases of non-fatal cardiac adverse events were reported after 12,964 injections (6482 bilateral injection sessions) in 626 patients. Four studies reported on death: 12 deaths were recorded after 6233 bilateral injection sessions in a total population of 554 subjects. CONCLUSIONS: We suggest that the risk of non-fatal systemic adverse events and death after same-session bilateral anti-VEGF injection is reasonably low, but larger studies with follow-ups of several years are needed to quantify the exact risk. STUDY REGISTRATION: Prospectively registered in PROSPERO, registration ID: CRD42023428254, registration date: 20/05/2023.

Long-term follow-up of a bilateral acute posterior multifocal placoid pigment epitheliopathy following COVID-19 infection: a case report.

BACKGROUND: Acute posterior multifocal placoid pigment epitheliopathy (APMPPE) is a rare inflammatory eye disorder that is characterized by the presence of multiple placoid lesions in the posterior pole of the eye. Relentless placoid chorioretinitis (RPC) is an inflammatory chorioretinopathy that combines clinical features of APMPPE and serpiginous chorioretinitis, which is a progressive condition with a high risk of visual disability. Patients with COVID-19 can develop various ocular manifestations, however, there have been limited reports of APMPPE and RPC associated with the infection. We report a case of a patient who developed APMPPE after a COVID-19 infection and subsequently progressed into RPC. CASE PRESENTATION: A 17-year-old male presented with a one-week history of painless gradual visual loss in both eyes. Two months prior to the visual symptoms, the patient had a SARS CoV-2 infection, confirmed by polymerase chain reaction test. Clinical findings with fundoscopy, optical coherence tomography and fluorescein angiography were consistent with APMPPE. Due to the severely affected vision in both eyes, the patient was started on 50 mg oral prednisolone daily, after which vision began to improve rapidly. Two months after symptom onset during steroid taper, the impression of continued inflammatory activity and new lesions in the retinal periphery of both eyes suggested RPC. Adalimumab 40 mg every other week was initiated with 12.5 mg prednisolone daily followed by slow tapering. Vision improved and five months after the start of the adalimumab treatment, the steroid was discontinued and there were no signs of active inflammation. The patient has been followed for a total of 21 months since presentation, had full visual recovery and good tolerance of the immunosuppressive treatment. CONCLUSION: COVID-19 might cause long-lasting activity of APMPPE. The scarcity of reports compared with the number of confirmed COVID-19 infections worldwide suggests a rare entity. The association of APMPPE with a variety of infections may suggest a common immunological aberrant response that might be triggered by various factors. Further examinations and case reports are needed to understand the role of biological therapy in the treatment of such cases.

Evaluation of a retinal oximetry image quality indicator in patients with cataract.

PURPOSE: To evaluate a new automated retinal oximetry image quality indicator with cataract as a clinical model. METHODS: Sixty-one eyes in 61 patients were imaged by the Oxymap T1 Retinal Oximeter at baseline and 25 eyes were also examined 3 weeks after cataract surgery. Image quality (0-10 on a continuous scale) was compared with standardized AREDS cataract grading and Pentacam lens densitometry. Associations with retinal oximetry measurements and visual acuity were examined. RESULTS: Image quality correlated with total, nuclear and posterior subcapsular cataract grades (ANOVA, p < 0.05), tended to be associated with lens densitometry and it improved from 4.3 ± 1.4 to 5.7 ± 1.0 (p < 0.05) after cataract surgery. Very low image quality, below 3, led to vessel detection failure in retinal oximetry images. Higher image qualities were linearly associated with higher measured retinal oxygen saturations (r = 0.52 in arteries and r = 0.46 in veins; p < 0.001). CONCLUSION: Retinal oximetry image quality deteriorated with increasing cataract density and improved after cataract surgery, supporting its use as a measure of optical clarity. The numerical quality indicator demonstrated a threshold below which images of poor optical quality should be discarded. Image quality affects the estimates of retinal oximetry parameters and should therefore be included in future analyses.

Comparison of temporal artery ultrasound versus biopsy in the diagnosis of giant cell arteritis.

BACKGROUND/OBJECTIVES: Giant cell arteritis (GCA) is a medical and ophthalmological emergency due to risk of stroke and sudden irreversible loss of vision. Fast and accurate diagnosis is important to prevent complications and long-term high dose glucocorticoids toxicity. Temporal artery biopsy is gold standard for diagnosing GCA. However, temporal artery ultrasound is a fast and non-invasive procedure which may provide a supplement or an alternative to biopsy. This study assesses the diagnostic performance of ultrasound and biopsy in the diagnosis of GCA. SUBJECTS/METHODS: Examination results of patients suspected of having GCA in the period from August 2018 to June 2019 were reviewed. Patients underwent clinical examination and blood tests. Within a few days of starting glucocorticoid treatment, temporal ultrasound and unilateral biopsy were performed. Experienced physicians established the final clinical diagnosis at 6-months follow-up. RESULTS: Seventy-eight patients underwent both ultrasound and biopsy. Thirty-five (45%) received the final clinical diagnosis of GCA. Compared with the final clinical diagnosis, biopsy had a sensitivity of 69% (51-83%) and a specificity of 100% (92-100%), and ultrasound a sensitivity of 63% (45-79%) and a specificity of 79% (64-94%). Area under the receiver operating characteristics curves were 0.84 and 0.71 for biopsy and ultrasound respectively (p = 0.048). False negative rate of ultrasound was 4 out of 78 (5%). CONCLUSION: Sensitivity of ultrasound is almost on par with that of biopsy although the overall diagnostic accuracy of ultrasound was slightly lower. We find that ultrasound is a reliable tool for first line diagnosis of GCA.

Multimodality Imaging in Cranial Giant Cell Arteritis: First Experience with High-Resolution T1-Weighted 3D Black Blood without Contrast Enhancement Magnetic Resonance Imaging.

In order to support or refute the clinical suspicion of cranial giant cell arteritis (GCA), a supplemental imaging modality is often required. High-resolution black blood Magnetic Resonance Imaging (BB MRI) techniques with contrast enhancement can visualize artery wall inflammation in GCA. We compared findings on BB MRI without contrast enhancement with findings on 2-deoxy-2-[18F]fluoro-D-glucose positron emission tomography/low-dose computed tomography (2-[18F]FDG PET/CT) in ten patients suspected of having GCA and in five control subjects who had a 2-[18F]FDG PET/CT performed as a routine control for malignant melanoma. BB MRI was consistent with 2-[18F]FDG PET/CT in 10 out of 10 cases in the group with suspected GCA. In four out of five cases in the control group, the BB MRI was consistent with 2-[18F]FDG PET/CT. In this small population, BB MRI without contrast enhancement shows promising performance in the diagnosis of GCA, and might be an applicable imaging modality in patients.

Bilateral Vertebral Artery Vasculitis-A Rare Manifestation of Giant Cell Arteritis and a Difficult Diagnosis Made Possible by 2-[18F]FDG PET/CT.

Giant cell arteritis (GCA) is the most common form of large vessel vasculitis. GCA is a medical and ophthalmological emergency, and rapid diagnosis and treatment with high-dose corticosteroids is critical in order to reduce the risk of stroke and sudden irreversible loss of vision. GCA can be difficult to diagnose due to insidious and unspecific symptoms-especially if typical superficial extracranial arteries are not affected. In these cases, verification of clinical diagnosis using temporal artery biopsy is not possible. This example illustrates the diagnostic value of hybrid imaging with 2-deoxy-2-[18F]fluoro-D-glucose positron emission tomography/computed tomography (2-[18F]FDG PET/CT), and the limitations of the temporal artery biopsy in bilateral vertebral GCA, causing transient ischemic attack in the visual cortex. In addition it indicates that inflammation in the artery wall can be visualized on 2-[18F]FDG PET/CT despite long term and ongoing high dose glucocorticoid treatment.

Macular perfusion velocities in the ocular ischaemic syndrome.

PURPOSE: To assess retinal perfusion in eyes with unilateral ocular ischaemic syndrome (OIS) and to compare with control subjects. METHODS: Retrospective case series. Linear blood flow velocities in macular vessels were estimated using motion-contrast fundus photography in eight patients with unilateral OIS (eight OIS eyes, seven fellow eyes) and 12 control subjects. The diagnosis of OIS was supported by carotid artery Doppler ultrasonography and pneumoplethysmographic measurement of ocular systolic perfusion pressure. RESULTS: Macular arterial blood flow velocity (median, range) was 1.8 (1.4-2.7) mm/s in OIS eyes, 4.0 (2.9-5.3) mm/s in fellow eyes (p = 0.016) and 3.8 (2.3-5.1) mm/s in control eyes (p = 0.0004 and p = 0.67 versus OIS and fellow eyes, respectively). Macular venous blood flow velocity was 1.5 (1.0-2.1) mm/s in OIS eyes, 2.6 (2.0-2.9) mm/s in fellow eyes (p = 0.016) and 2.7 (1.8-3.5) mm/s in control eyes (p = 0.0007 and p = 0.64). Arterial velocities were below or equal to the lowest value observed in control subjects (≤2.3 mm/s) in seven of eight eyes with OIS. Visual acuity 0.7 or worse was found in two OIS eyes with arterial velocities below 1.7 mm/s and venous velocities below 1.3 mm/s and together with neovascular glaucoma or polycythemia vera (one eye each). CONCLUSION: Motion-contrast imaging revealed markedly reduced macular perfusion velocities in OIS eyes compared with unaffected fellow eyes and healthy control eyes. The method appears to provide a clinically meaningful quantitative measure of macular hypoperfusion.

Non-invasive imaging of retinal blood flow in myeloproliferative neoplasms.

PURPOSE: To study the circulation in the retinal vessels in patients with blood dyscrasia due to myeloproliferative neoplasms using non-invasive retinal imaging. METHODS: Prospective consecutive case series of seven treatment-naïve patients with chronic myeloid leukaemia (n = 2), polycythemia vera (n = 4), essential thrombocytosis (n = 1) examined before and after cytoreductive treatment. We investigated retinal circulation with motion-contrast imaging, retinal oximetry and spectral-domain optical coherence tomography. RESULTS: Retinal venous blood velocity increased by 8.14% (CI95 3.67% to 12.6%, p = 0.004) and retinal arterial oxygen saturation increased by 7.23% (CI95 2.9% to 11.6%, p = 0.010) at follow-up (mean 12 weeks, range 5-14 weeks) where complete haematological remission had been achieved by cytoreductive treatment. Abnormal optical coherence tomography reflectivity patterns were present at baseline in patients with chronic myeloid leukaemia and were replaced by normal patterns at follow-up. Retinopathy, in the form of cotton-wool spots and retinal haemorrhages, was found at presentation in the two patients with chronic myeloid leukaemia and in one patient with polycythemia vera. The retinopathy had resolved at follow-up in all patients. CONCLUSION: With non-invasive retinal imaging, we were able to demonstrate increased retinal venous blood velocity, increased retinal arterial blood oxygenation and normalization of intravascular reflectivity patterns after successful treatment of myeloproliferative neoplasms. Larger prospective studies are needed to assess the prognostic value of these non-invasive imaging methods in predicting circulatory complications in myeloproliferative neoplasms.

Dark adaptation in relation to choroidal thickness in healthy young subjects: a cross-sectional, observational study.

BACKGROUND: Dark adaptation is an energy-requiring process in the outer retina nourished by the profusely perfused choroid. We hypothesized that variations in choroidal thickness might affect the rate of dark adaptation. METHOD: Cross-sectional, observational study of 42 healthy university students (mean age 25 ± 2.0 years, 29 % men) who were examined using an abbreviated automated dark adaptometry protocol with a 2° diameter stimulus centered 5° above the point of fixation. The early, linear part of the rod-mediated dark adaptation curve was analyzed to extract the time required to reach a sensitivity of 5.0 × 10(-3) cd/m2 (time to rod intercept) and the slope (rod adaptation rate). The choroid was imaged using enhanced-depth imaging spectral-domain optical coherence tomography (EDI-OCT). RESULTS: The time to the rod intercept was 7.3 ± 0.94 (range 5.1 - 10.2) min. Choroidal thickness 2.5° above the fovea was 348 ± 104 (range 153-534) µm. There was no significant correlation between any of the two measures of rod-mediated dark adaptation and choroidal thickness (time to rod intercept versus choroidal thickness 0.072 (CI95 -0.23 to 0.38) min/100 µm, P = 0.64, adjusted for age and sex). There was no association between the time-to-rod-intercept or the dark adaptation rate and axial length, refraction, gender or age. CONCLUSION: Choroidal thickness, refraction and ocular axial length had no detectable effect on rod-mediated dark adaptation in healthy young subjects. Our results do not support that variations in dark adaptation can be attributed to variations in choroidal thickness.

Retinal characteristics during 1 year of insulin pump therapy in type 1 diabetes: a prospective, controlled, observational study.

PURPOSE: To investigate changes in retinal metabolism, function, structure and morphology in relation to initiation of insulin pump therapy (continuous subcutaneous insulin infusion, CSII). METHODS: Visual acuity, retinopathy level, dark adaptation kinetics, retinal and subfoveal choroidal thickness, macular perfusion velocities, retinal vessel diameters and blood oxygen saturations were measured at baseline and after 1, 4, 16, 32 and 52 weeks in 31 patients with type 1 diabetes who started CSII and 20 patients who continued multiple daily insulin injections (MDI). RESULTS: One year of CSII reduced haemoglobin A1c (HbA1c ) by 1.6% (17.8 mmol/mol) compared with 0.3% (3.1 mmol/mol) in the MDI group (p < 0.0001). Central retinal thickness increased by 1.5% in the CSII group (within-group p = 0.0098; between-group p = 0.063) without producing macular oedema. No detectable change was found in any other primary outcome measure. The proportion of patients with retinopathy worsening did not differ between groups. At baseline, longer disease duration was associated with higher retinal artery oxygen saturation (p = 0.014) and lower macular venous perfusion velocity (p = 0.045). CONCLUSION: One year of CSII led to an HbA1c reduction relative to continued MDI and a small increase in retinal thickness but not to early retinopathy worsening or to changes in retinal vascular, structural or functional characteristics. Longer duration of type 1 diabetes appears to be associated with lower macular venous perfusion velocity and higher retinal artery oxygen saturation. The latter could potentially reflect cumulative glycaemia.

Retinal hemodynamic oxygen reactivity assessed by perfusion velocity, blood oximetry and vessel diameter measurements.

PURPOSE: To test the oxygen reactivity of a fundus photographic method of measuring macular perfusion velocity and to integrate macular perfusion velocities with measurements of retinal vessel diameters and blood oxygen saturation. METHODS: Sixteen eyes in 16 healthy volunteers were studied at two examination sessions using motion-contrast velocimetry and retinal oximetry with vessel diameter corrections. To test oxygen reactivity, participants were examined during normoxia, after 15 min of hyperoxia and finally after 45 min of normoxia. Repeatability was assessed by intraclass correlation coefficients (ICC) and limits of agreement. RESULTS: Fifteen minutes of hyperoxia was accompanied by mean reductions in arterial and venous perfusion velocities of 14% and 16%, respectively (p = 0.0080; p = 0.0019), constriction of major arteries and veins by 5.5% and 8.2%, respectively (p < 0.0001), increased retinal arterial oxygen saturation from 95.1 ± 5.0% to 96.6 ± 6.4% (p = 0.038) and increased retinal venous oxygen saturation from 62.9 ± 6.7% to 70.3 ± 7.8% (p = 0.0010). Parameters returned to baseline levels after subsequent normoxia. Saturation and vessel diameter ICCs were 0.88-0.98 (range). For perfusion velocities, short-term ICCs were 0.79-0.82 and long-term ICCs were 0.06-0.11. Intersession increases in blood glucose were associated with reductions in perfusion velocities (arterial p = 0.0067; venous p = 0.018). CONCLUSION: Oxygen reactivity testing supported that motion-contrast velocimetry is a valid method for assessing macular perfusion. Results were consistent with previous observations of hyperoxic blood flow reduction using blue field entoptic and laser Doppler velocimetry. Retinal perfusion seemed to be regulated around individual set points according to blood glucose levels. Multimodal measurements may provide comprehensive information about retinal metabolism.