Ocular motor nerve palsy in patients with diabetes: High-resolution MR imaging of nerve enhancement.

OBJECTIVE: To evaluate the extent of signal abnormality in impaired ocular motor nerves using high signal and spatial resolution MRI sequences and to discuss the involvement of inflammatory or microvascular impairment in patients with diabetic ophthalmoplegia. METHODS: We conducted a retrospective study of 10 patients referred for acute ocular motor nerve palsy in the context of diabetes mellitus from September 15th, 2021 to April 24th, 2022. 3T MRI evaluation included diffusion, 3D TOF, FLAIR, coronal STIR and post-injection 3D T1 SPACE DANTE sequences. RESULTS: Ten patients were included: 9 males and 1 female aged from 46 to 79 years. Five patients presented with cranial nerve (CN) III palsy, and 5 presented with CN VI palsy. Third nerve palsy was pupil-sparing in 4 patients and pupil-involved in 1 patient. Pain was associated in all patients with CN III deficiencies and in 2 patients CN VI deficiencies. In all patients, MRI sequences ruled out mass effect and vascular pathology, such as acute stroke or aneurysm. Eight patients presented with STIR hypersignals, some with enlargement of the involved nerve. The diagnosis was confirmed through a post-injection 3D T1 SPACE DANTE sequence, which showed extended enhancement along the abnormal portion of the nerve. CONCLUSION: High-resolution MRI evaluation of diplopia in diabetic patients is used to rule out a diagnosis of acute stroke and contributes to the positive diagnosis of ocular motor nerve impairment, possibly combining the influences of inflammatory and microvascular phenomena. Dedicated MR imaging should be included in the initial diagnosis and longitudinal follow-up of patients with diabetic ophthalmoplegia.

[Eales' disease]. / La maladie de Eales.

The syndrome of recurrent vitreous hemorrhages in young men was described for the first time by Henry Eales in 1880. The association with a clinical manifestation of ocular inflammation was reported 5years later. Eales disease affects young adults who present with ischemic retinal vasculitis, with the peripheral retina most commonly affected. Most cases have been reported in South Asia. Although the etiology of this abnormality is unknown, it may be related to an immune sensitivity to Mycobacterium tuberculosis antigens. Its pathogenesis is related to extensive ischemia that affects the retina, secondary to an obliterative retinal vasculopathy with release of angiogenic factors of the VEGF type. Involvement of the retina is the hallmark of the disease, which manifests as follows: periphlebitis, retinal capillary ischemia most often affecting the periphery with secondary proliferative retinopathy and retinal and/or papillary neovascularization, recurrent vitreous hemorrhages and tractional retinal detachment. These complications are potentially blinding. The natural history of Eales disease varies, with temporary or permanent remission in some cases and continuous progression in others. Progression is often bilateral, which necessitates regular follow-up. The treatment of Eales disease depends on the stage of the disease and is not well defined. Observation only, pars plana vitrectomy surgery and/or intravitreal injections of anti-VEGF are recommended in cases of vitreous hemorrhage, associated with corticosteroids when retinal vasculitis is present. Laser pan-retinal photocoagulation is necessary when neovascularization is present.

High prevalence of undiagnosed diabetes and high risk for diabetes using HbA1c criteria in middle-aged patients undergoing cataract surgery.

AIM: This study assessed the prevalence of undiagnosed diabetes and a high risk for diabetes using glycated haemoglobin (HbA(1c)) values in middle-aged patients undergoing cataract surgery. METHODS: The study comprised 137 consecutive patients, aged 40 to 65 years, with no known diabetes undergoing cataract surgery at a French national eye centre. Fasting glucose, obesity parameters, and vascular and ocular cataract risk factors were recorded. HbA1c was measured on the day of cataract surgery. Prevalence of undiagnosed diabetes (HbA(1c) ≥ 6.5%) and a high risk of diabetes (≥ 6.0% but < 6.5%) in the study population was compared with recently published estimates from general French, Dutch and US populations. RESULTS: In the study population, undiagnosed diabetes was found in 12 patients (9%; 95% CI: 4-14%) and a high risk for diabetes in 47 (34%; 95% CI: 26-42%). These prevalences were four to 11 times higher than the corresponding population-based estimates, whereas obesity parameters recorded in the general populations and in our study population were similar according to HbA1c subcategories. Of the 125 patients with HbA1c less than 6.5%, values were higher in patients without ocular cataract risk factors (n = 73; 58%) than in those with cataract risk factors (n = 52; 42%) at 5.92 ± 0.30% and 5.57 ± 0.29%, respectively (P < 0.001), thereby suggesting a significant role for blood glucose levels in cataractogenesis. CONCLUSION: Middle-aged patients undergoing cataract surgery showed a high prevalence of diabetes and a high risk for diabetes not recognized before surgery, suggesting that this patient population should be targeted for diabetes screening and prevention.

Hypoglycaemia is associated with the absence of a decrease in diurnal macular thickness in patients with diabetic macular oedema.

AIM: Spontaneous diurnal variations measured by optical coherence tomography (OCT) have been reported in diabetic macular oedema (DME) together with a daytime decrease in central macular thickness (CMT). For this reason, this study aimed to investigate the influence of acute glucose and blood pressure changes on daytime variations in CMT in patients with DME. METHODS: In this prospective observational study of type 1 (n=4) and type 2 (n=18) diabetic patients with DME, OCT scans, capillary blood glucose, and systolic and diastolic blood pressure measurements were performed at 9 a.m., 12 a.m., 3 p.m., 6 p.m. and again at 9 a.m. the day after. At the same time, the study protocol included simultaneous ambulatory blood pressure and glucose monitoring over a 24-h period. Hypoglycaemic episodes, defined as glucose values<60mg/dL, were also recorded. RESULTS: CMT decreased consistently between 9 a.m. and 6 p.m. in 10 patients (from 374±82µm to 337±72µm; P=0.01) and increased or remained steady in 12 others (from 383±136µm to 390±149µm; P=0.58), with a significant difference in CMT absolute change between the two groups (P<0.001). In the study population as a whole, the lower the mean diurnal blood glucose, the smaller the decrease in CMT during the day (P=0.027). Also, eight (67%) of the 12 patients with a flat CMT profile experienced a diurnal hypoglycaemic event whereas none of those with a CMT decrease had hypoglycaemia (P=0.002). CONCLUSION: Hypoglycaemic events may explain the lack of diurnal CMT decrease in diabetic patients with DME. However, further studies need to be conducted to evaluate whether having no diurnal CMT decrease is associated with a poorer visual prognosis and whether it can be modified by better glucose control.