COVID-19 and macular edema: a necessarily blindness?

Graefe's Archive for Clinical and Experimental Ophthalmology -     

Retinal disease in the C3 glomerulopathies and the risk of impaired vision

Background: Dense deposit disease and atypical hemolytic uremic syndrome are often caused by Complement Factor H (CFH) mutations. This study describes the retinal abnormalities in dense deposit disease and, for the first time, atypical haemolytic uremic syndrome. It also reviews our understanding of drusen pathogenesis and their relevance for glomerular disease. Methods: Six individuals with dense deposit disease and one with atypical haemolytic uremic syndrome were studied from 2 to 40 years after presentation. Five had renal transplants. All four who had genetic testing had CFH mutations. Individuals underwent ophthalmological review and retinal photography, and in some cases, optical coherence tomography, and further tests of retinal function. Results: All subjects with dense deposit disease had impaired night vision and retinal drusen or whitish-yellow deposits. Retinal atrophy, pigmentation, and hemorrhage were common. In late disease, peripheral vision was restricted, central vision was distorted, and there were scotoma from sub-retinal choroidal neovascular membranes and atypical serous retinopathy. Drusen were present but less prominent in the young person with atypical uremic syndrome due to a heterozygous CFH mutation. Conclusions: Drusen are common in forms of C3 glomerulopathy caused by compound heterozygous or heterozygous CFH mutations. They are useful diagnostically but also impair vision. Drusen have an identical composition to glomerular deposits. They are also identical to the drusen of age-related macular degeneration, and may respond to the same treatments. Individuals with a C3 glomerulopathy should be assessed ophthalmologically at diagnosis, and monitored regularly for vision-threatening complications.     

Diabetic macular ischaemia- a new therapeutic target?

Diabetic macular ischaemia (DMI) is traditionally defined and graded based on the angiographic evidence of an enlarged and irregular foveal avascular zone. However, these anatomical changes are not surrogate markers for visual impairment. We postulate that there are vascular phenotypes of DMI based on the relative perfusion deficits of various retinal capillary plexuses and choriocapillaris. This review highlights several mechanistic pathways, including the role of hypoxia and the complex relation between neurons, glia, and microvasculature. The current animal models are reviewed, with shortcomings noted. Therefore, utilising the advancing technology of optical coherence tomography angiography (OCTA) to identify the reversible DMI phenotypes may be the key to successful therapeutic interventions for DMI. However, there is a need to standardise the nomenclature of OCTA perfusion status. Visual acuity is not an ideal endpoint for DMI clinical trials. New trial endpoints that represent disease progression need to be developed before irreversible vision loss in patients with DMI. Natural history studies are required to determine the course of each vascular and neuronal parameter to define the DMI phenotypes. These DMI phenotypes may also partly explain the development and recurrence of diabetic macular oedema. It is also currently unclear where and how DMI fits into the diabetic retinopathy severity scales, further highlighting the need to better define the progression of diabetic retinopathy and DMI based on both multimodal imaging and visual function. Finally, we discuss a complete set of proposed therapeutic pathways for DMI, including cell-based therapies that may provide restorative potential.     

Anti-tubercular therapy in the treatment of tubercular uveitis: A systematic review and meta-analysis

We quantitatively evaluated the efficacy of antitubercular therapy (ATT) in tubercular uveitis (TBU) patients. Main outcome measures include inflammation recurrence, inflammation reduction, complete resolution of inflammation, improved visual acuity (VA), ability to taper corticosteroids to < 10 mg/day without inflammatory progression, and use of adjunctive immunosuppressants while on ATT. This review is prospectively registered in PROSPERO (CRD42020206845). Forty-nine studies reporting data for 4,017 TBU patients were included. In comparative studies, the odds ratio (OR) of inflammatory recurrence was 0.33 (95%CI:0.19-0.60) for TBU patients treated with ATT±corticosteroid versus no ATT. For TBU patients treated with ATT±corticosteroid, the pooled absolute incidences of inflammatory recurrence, inflammatory reduction, complete resolution of inflammation, and visual acuity improvement were 13% (n=310/2,216; 95%CI:9-18), 81% (n=217/276; 95%CI: 62-95), 83% (n=1,167/1,812; 95%CI: 77-89), and 65% (n=347/542; 95%CI:51-78), respectively. Corticosteroids were tapered to <10 mg/day without inflammatory progression in 91% (n=326/395; 95%CI:78-99) of patients, 9% (n=121/1,376; 95%CI:6-13) of whom were administered concomitant immunosuppressive agents alongside ATT. We conclude that treatment of TBU with ATT±corticosteroid is associated with a high level of control or improvement of inflammation. More prospective studies with detailed reporting of ATT regimens, patient subgroups, and outcomes are required to better evaluate ATT effectiveness.     

The relationship between nasal and conjunctival cultures of antimicrobial-resistant isolates of methicillin-resistant Staphylococcus aureus

PurposeNasal screening is performed to avoid the complications of postoperative surgical site infections (SSI), especially those due to antimicrobial-resistant species such as methicillin-resistant Staphylococcus aureus (MRSA). This study examined the relationship between bacterial isolates from the conjunctiva and the nasal cavity.MethodsAll patients were diagnosed with ocular surface infections, and the organisms in the conjunctiva and the nasal cavity were isolated. We investigated the relationship of the following antimicrobial-resistant bacteria between the conjunctiva and the nose: MRSA, methicillin-resistant CNS (MRCNS), levofloxacin-resistant (LVFX-R) Corynebacterium spp. Data were analyzed using Fisher’s exact test, and the odds ratio was examined.ResultsThis study included 188 eyes of 188 subjects (87 males and 101 females; mean age 58.5 years, range 11–97 years). MRSA (4 eyes), MRCNS (29 eyes), and LVFX-R Corynebacterium spp. (41 eyes) were identified from the conjunctiva, and MRSA (6 eyes), MRCNS (38 eyes), and LVFX-R Corynebacterium spp. (41 eyes) were identified from the nasal cavity. There was a significant relationship detected between the conjunctiva and the nose for MRSA, MRCNS, and LVFX-R Corynebacterium spp. MRSA displayed high sensitivity (0.750, 95% confidence interval [CI]; 0.301 to 0.987) and specificity (0.984, 95% CI; 0.953 to 0.996) in nasal cavity cultures, and the odds ratio was 181.00 times (95% CI; 18.41 to 2320).ConclusionThis study showed a significant relationship between conjunctival and nasal cultures of MRSA, MRCNS, and LVFX-R Corynebacterium spp., suggesting that nasal cavity culture is a potentially useful screening method for detecting resistant bacteria, especially MRSA, in the conjunctiva.