Neuro-ophthalmology of diabetes

Neuro-ophthalmological manifestations of diabetes mellitus during COVID-19-related lockdown in India

Purpose

The coronavirus disease 19 (COVID-19) pandemic has resulted in a huge impact on the health care system. Diversion of health care workforce toward management of a high number of COVID-19 cases and lockdown restrictions have affected the follow-up of patients. The objective of this study was to analyze the impact of this situation on the control of diabetes, eventually resulting in related neuro-ophthalmological complications.

Methods

This retrospective case series included diabetic patients visiting the neuro-ophthalmology clinic at a tertiary care eye center in India from 25 March 2020 to 25 September 2020 during the lockdown. The incidence of diabetes-related neuro-ophthalmological complications, including third, fourth, sixth nerve palsies and non-arteritic anterior ischemic optic neuropathy (NAION) was evaluated and compared with that of the same period during 2019.

Results

Overall disease incidence rate was significantly higher in the year 2020 (60.2%) compared to the previous year of 2019 (29.8%). The proportion of third nerve palsy (4.8% vs 16.3%, P < 0.001) and NAION (0.3% vs 14.3%, P < 0.001) had increased. Even though the percentage of sixth nerve palsy was 25% in 2020, this was not significantly different from 2019. There was a reduction in the percentage of fourth nerve palsy cases from the year 2019 to 2020.

Conclusion

There was a significant increase in diabetes-related neuro-ophthalmic complications during the COVID-19 lockdown. This can possibly be attributed to worsening of glycemic control in diabetic patients.

Ocular manifestations of endocrine disorders

Endocrinopathies are prevalent diseases that typically affect multiple organs, and the eye and orbital tissues are often involved in endocrine disorders. Some conditions, such as diabetes and thyroid gland dysfunction, may cause serious eye pathology and even blindness. A clear insight into the pathogenesis of endocrinopathies and their ocular manifestations would enhance preventive and therapeutic measures and reduce the incidence of sight-threatening complications. This review discusses the ocular manifestations of several endocrine disorders that eye care providers are likely to encounter in clinical practice.

Non-arteritic ischaemic optic neuropathy (NAION) in patients under 50 years of age

PURPOSE

The goal of our study was to compare the case histories and clinical findings in three young patients (aged<50 years) who had undergone their first attack of non-arteritic ischaemic optic neuropathy (NAION). We intended to consider whether NAION at a relatively young age might comprise a separate pathological and diagnostic entity.

RESULTS

All three cases revealed some common characteristics. All of them experienced recurrent attacks with bilateral manifestations that led to severe loss of vision and visual field defects. The patients had also suffered from diabetes mellitus for a long time, but none of them had diabetic retinopathy.

CONCLUSION

The case histories of these relatively young patients showed some differences, including recurrences and more severe loss of vision, to those of elderly patients. However, all the signs we found had been reported previously, although much less frequently, in NAION cases among elderly patients. The clinical and laboratory findings definitely exclude the possibility of an alternative diagnosis. Hence, our results do not support the notion of a different pathomechanism of NAION at a young age and its existence as a separate disease entity.

Visual Outcome in Eyes With Asymptomatic Optic Disc Edema

BACKGROUND

Asymptomatic optic disc edema may last for months before conversion to anterior ischemic optic neuropathy (AION). Alternatively, the optic disc edema may resolve with preservation of normal vision. The conversion rate of asymptomatic optic disc edema to AION has not been prospectively studied. We prospectively followed patients with asymptomatic disc edema to determine this conversion rate.

METHODS

The cohort was followed from 1991 to 2000 at a single ophthalmology clinic in Israel. There were 23 patients aged 47-74 years with asymptomatic disc edema and no signs of optic nerve dysfunction in whom the disc edema had been incidentally discovered on routine fundus examination performed for diabetes, hypertension, or follow-up after AION in the fellow eye.

RESULTS

In 9 (36%) eyes, optic disc edema progressed to overt AION with a mean latency of 16.8 weeks (range 2-80 weeks). In 16 (64%) eyes, optic disc edema resolved without loss of vision with a mean latency of 15.5 weeks (range 4-44 weeks). The conversion rate to AION was 40% in patients who had had AION in the fellow eye, 31% in patients with diabetes, 43% in patients with diabetic retinopathy, and 0% in four amiodarone-treated patients.

CONCLUSION

Asymptomatic disc edema generally resolves with no visual loss, but one third of patients progress to full-blown AION. Diabetes mellitus is common in patients with asymptomatic optic disc edema. Perhaps patients diagnosed as having diabetic papillopathy actually have an impending AION that does not progress to overt disease.