Myasthenia Gravis: Novel Findings and Perspectives on Traditional to Regenerative Therapeutic Interventions

The prevalence of myasthenia gravis (MG), an autoimmune disorder, is increasing among all subsets of the population leading to an elevated economic and social burden. The pathogenesis of MG is characterized by the synthesis of autoantibodies against the acetylcholine receptor (AChR), low-density lipoprotein receptor-related protein 4 (LRP4), or muscle-specific kinase at the neuromuscular junction, thereby leading to muscular weakness and fatigue. Based on clinical and laboratory examinations, the research is focused on distinguishing MG from other autoimmune, genetic diseases of neuromuscular transmission. Technological advancements in machine learning, a subset of artificial intelligence (AI) have been assistive in accurate diagnosis and management. Besides, addressing the clinical needs of MG patients is critical to improving quality of life (QoL) and satisfaction. Lifestyle changes including physical exercise and traditional Chinese medicine/herbs have also been shown to exert an ameliorative impact on MG progression. To achieve enhanced therapeutic efficacy, cholinesterase inhibitors, immunosuppressive drugs, and steroids in addition to plasma exchange therapy are widely recommended. Under surgical intervention, thymectomy is the only feasible alternative to removing thymoma to overcome thymoma-associated MG. Although these conventional and current therapeutic approaches are effective, the associated adverse events and surgical complexity limit their wide application. Moreover, Restivo et al. also, to increase survival and QoL, further recent developments revealed that antibody, gene, and regenerative therapies (such as stem cells and exosomes) are currently being investigated as a safer and more efficacious alternative. Considering these above-mentioned points, we have comprehensively reviewed the recent advances in pathological etiologies of MG including COVID-19, and its therapeutic management.

Postoperative Mycobacteroides abscessus subsp. abscessus endophthalmitis: Clinical analysis of 12 clustered adults and a proposed therapeutic algorithm

PURPOSE

Postoperative endophthalmitis caused by nontuberculous mycobacterium is a rare but devastating complication after intraocular surgery. However, optimal treatment strategies remain undetermined in view of its rarity.

METHODS

We investigated the cases of culture-proven postoperative Mycobacteroides abscessus subsp. abscessus endophthalmitis in southern Taiwan, focusing on clinical manifestations and microbiological study, and aimed to describe clinical staging and to propose a therapeutic modality for this disease.

RESULTS

Twelve cases, including two published cases, were treated in two medical centers in southern Taiwan between Aug. 2011 and Dec. 2016, and all ever received cataract surgery at one clinic. Their disease courses could be categorized into four distinct stages, i.e., the initial, quiescent, recurrent, and end stage, and some cases experienced 1-4 cycles of quiescent-recurrent stages. Although all eyes ended up with phthisis or were eviscerated, the affected eyes receiving pars plana vitrectomy (PPV) tended to become quiescent and survived longer than those without PPV (adjusted hazard ratio: 13.9, p < 0.05). Eight isolates of eight patients were available for microbiological study. All isolates were susceptible to amikacin, and inducible clarithromycin resistance was observed in 100% of isolates.

CONCLUSION

Despite the preservation of vision in postoperative M.abscessus endophthalmitis remained a challenge, a stage-based approach is proposed, which may facilitate decision-makings for the future study.

The relationship between age, axial length and retinal nerve fiber layer thickness in the normal elderly population in Taiwan: The Chiayi eye study in Taiwan

AIMS

To interpret how the thickness of the peripapillary retinal nerve fiber layer (RNFL) changes with increasing age, axial length, or anterior chamber depth as measured by spectral domain optical coherence tomography (OCT) in the normal elderly population in Taiwan.

METHODS

A total of 82 volunteers (143 eyes) were enrolled. Generalized estimating equations were used to evaluate the correlation.

RESULTS

The RNFL was significantly thinner in the superonasal (p = 0.004), inferotemporal (p = 0.046), and temporolower (p = 0.009) segments with age. The same trend was also observed in the superotemporal (p = 0.330) segment, although it was not statistically significant. The global RNFL thickness decreased by 4.97 μm per decade (β = -0.497; p = 0.021), and thinning was significant in the superonasal (-9.90 μm per decade, p < 0.001) and temporolower (-6.78 μm per decade, p < 0.001) segments; the same trend showed borderline significance in the superotemporal (-6.96 μm per decade, p = 0.073) and inferotemporal (-7.23 μm per decade, p = 0.059) segments. In eyes with longer axial length, the RNFLs significantly decreased in the non-temporal segments. Global RNFL thickness decreased by 3.086 μm for each additional millimeter of axial length (β = -3.086; p < 0.001).

CONCLUSIONS

Changes in RNFL thickness were correlated with age in the superonasal, superotemporal, inferotemporal, and temporolower segments, and were correlated with axial length in the non-temporal segments. Anterior chamber depth was not correlated with RNFL thickness.

Rapid regression of cystoid macular edema associated with cytomegalovirus retinitis in adult acute myeloid leukemia by intravitreal methotrexate combined with oral valganciclovir: A case report with comparison of binocular outcome

Cytomegalovirus (CMV) retinitis is a late complication of organ and hematopoietic stem cell transplant, the risk of which depends on the degree of immunosuppression. With the institution of preemptive ganciclovir therapy early after transplant, most patients survive episodes of life-threatening CMV infection during the early months (usually the first 3 months) after transplant and hence late onset of CMV disease, such as CMV retinitis, is being recognized more frequently. Direct involvement of the macula or optic head remains the leading cause of visual loss in patients with CMV retinitis, but there are few studies investigating the management of this condition.

Herein, we present the case of 28-year-old man who had acute myeloid leukemia and developed CMV retinitis with bilateral cystoid macular edema and optic swelling in the right eye 6 months after bone marrow transplant. He received treatment with intravitreal methotrexate in the right eye in combination with oral valganciclovir. Visual acuity improved 1 month after four weekly injections of intravitreal methotrexate 400 µg/0.1 mL. Resolved disc swelling and regression of macular edema were also observed. By comparing binocular outcome, we present our findings and discuss the possible efficacy and safety of this treatment with respect to regression of anatomical damage and improvement in visual acuity.

Axial length and subfoveal choroidal thickness in individuals with age-related macular degeneration

PURPOSE

To compare axial length (AL) and subfoveal choroidal thickness (SFCT) between individuals with age-related macular degeneration (AMD) and controls with no lesions.

METHODS

This was a case-control study. In total, 853 eyes of 484 patients (>65 years), including 397 eyes at various AMD stages and 456 eyes with no fundus lesions (controls) were recruited. Using color fundus photography, eyes were grouped according to AMD degree. AL was automatically measured using IOL Master and SFCT was manually measured by two independent observers. The associations among age, AL, SFCT, and each AMD grade were analyzed.

RESULTS

Out of 853 eyes, 456 had no lesions, 217 contained drusen only, 134 had early AMD, and 46 had late AMD. The eyes with late AMD were older (p = 0.007) and had longer AL (p ≥ 0.001) and thinner SFCT (p < 0.001) compared with groups of no fundus lesions, drusen only, and early AMD. SFCT in eyes with late AMD decreased by 19.20 μm (p = 0.049), 24.78 μm (p = 0.029), and 15.56 μm (p = 0.162) compared with groups of no fundus lesions, drusen only, and early AMD, respectively. SFCT decreased by 14.18 μm/mm increase in AL (p < 0.001). The odds ratio (OR) for late AMD by longer AL (≥25 mm) and thinner SFCT (<240 μm) was 4.54 (χ² = 9.36; p = 0.002) and 4.86 (χ² = 17.62; p < 0.001), respectively, and was 9.57 (χ² = 18.07; p < 0.001) when both AL ≥ 25 ≥m and SFCT < 240 μm.

CONCLUSION

Eyes with late AMD have distinct reduced SFCT and elongated AL. Eyes with thinner SFCT and longer AL showed high ORs for late AMD and even higher ORs when both factors were simultaneously present. These findings illustrate the crucial pathophysiological role of these two important ocular fac tors and arouse our attention to patients with both characteristics, especially in Asian countries where the prevalence of myopia are disturbingly high.