Progression of diabetic retinopathy after endophthalmitis

Targeting the Gut-Eye Axis: An Emerging Strategy to Face Ocular Diseases

The human microbiota refers to a large variety of microorganisms (bacteria, viruses, and fungi) that live in different human body sites, including the gut, oral cavity, skin, and eyes. In particular, the presence of an ocular surface microbiota with a crucial role in maintaining ocular surface homeostasis by preventing colonization from pathogen species has been recently demonstrated. Moreover, recent studies underline a potential association between gut microbiota (GM) and ocular health. In this respect, some evidence supports the existence of a gut-eye axis involved in the pathogenesis of several ocular diseases, including age-related macular degeneration, uveitis, diabetic retinopathy, dry eye, and glaucoma. Therefore, understanding the link between the GM and these ocular disorders might be useful for the development of new therapeutic approaches, such as probiotics, prebiotics, symbiotics, or faecal microbiota transplantation through which the GM could be modulated, thus allowing better management of these diseases.

Ocular surface microbiome in diabetes mellitus

This cross-sectional, age- and gender-matched study included 20 eyes of non-diabetic subjects (non-DM group) and 60 eyes of type 2 diabetes mellitus (DM group). Subgroups of DM were classified by diabetic retinopathy (DR) staging into no DR (DM-no DR), non-proliferative DR (DM-NPDR), proliferative DR (DM-PDR), and by glycemic control (well-controlled DM; HbA1c < 7%, poorly controlled DM; HbA1c ≥ 7%). Conjunctival swabs were performed for ocular surface microbiome analysis using conventional culture and next-generation sequencing analysis (NGS). A higher culture-positive rate was found in DM (15%) than in non-DM group (5%) (p value = 0.437). Pathogenic organisms and antibiotic-resistant strains were detected in the DR groups (DM-NPDR and DM-PDR). The NGS analysis showed that potentially pathogenic bacteria such as Enterobacteriaceae, Neisseriaceae, Escherichia-Shigella, and Pseudomonas predominated in DM, especially in DR. There was dissimilarity in the ocular surface microbiome between DM and non-DM groups. The subgroup analysis showed that the DR group had significantly different microbial community from DM-no DR and non-DM groups (p value < 0.05). The microbial community in the poorly controlled DM was also significantly different from well-controlled DM and non-DM groups (p < 0.001). Using the NGS method, our study is the first to signify the importance of DR and glycemic control status, which affect the changes in the ocular surface microbiome.

Risk factors for endophthalmitis after cataract surgery in diabetic patients: a case control study

AIM

To identify risk factors associated with post-cataract surgery endophthalmitis (PCE) in type 2 diabetic patients.

METHODS

A hospital-based retrospective case-control study was conducted on 194 type 2 diabetic patients undergoing cataract surgery in Rajavithi Hospital from January 2007 to December 2015. Fifteen patients with PCE were included as the case group and 179 patients without PCE were included as the control group. Potential factors associated with PCE among both groups including demographics, pre-operative characteristics, surgical settings and complications, were statistically analyzed using Chi-square testing and a logistic regression model.

RESULTS

Within the case group, 53% were females and the median age was 68y. Univariate analysis of pre-operative characteristics, surgical settings and complications revealed that recent pre-operative fasting plasma glucose, insulin therapy, presence of diabetic retinopathy, and severe non-proliferative or proliferative diabetic retinopathy were significantly associated with PCE. In a multivariate analysis adjusting for blood glucose level, insulin treatment was the only significant factor associated with an increased risk of PCE (OR 3.9, 95%CI 1.0-15.0, P=0.04) compared to patients without insulin treatment. The most common causative organisms were gram-positive bacteria (89%). Staphylococcus species represented the most common group (67%). Median best corrected visual acuity at 1-month and 3-month follow-up was equal at 0.7 logMAR (20/100).

CONCLUSION

The authors identify insulin treatment as the only risk factor associated with endophthalmitis after cataract surgery in type 2 diabetic patients. Further studies with serum levels of pre-operative glycated hemoglobin (HbA_1c) and post-operative fasting plasma glucose level are essential to truly demonstrate the role of peri-operative glycemic markers as a risk factor for PCE.

Clinical course and visual outcome in patients with diabetes mellitus and uveitis

Purpose

We report the clinical course and visual outcome of patients with diabetes mellitus (DM) who subsequently developed uveitis from any cause.

Methods

Longitudinal, retrospective case note review.

Results

A total of 36 patients (M/F: 18/18, 58 eyes) were included, Of the 36 patients, 35 had Type 2 DM and one had Type 1 DM. Mean age of onset of DM was 49 years and uveitis 55 years. The uveitis was bilateral in 22 (61%) patients. There were 19 patients with anterior uveitis, 12 with panuveitis and 5 with intermediate uveitis. Mean follow up was 4.4 years (range 1-18). Mean number of uveitis recurrences was 3 (range 1-7). Causes of vision of 6/18 or worse appeared related to the uveitis in 9 eyes and diabetes in 4 eyes. Cataract occurred in 22 eyes, glaucoma in 17 eyes, and cystoid macular oedema in 10 eyes. Diabetic retinopathy was detected in 38 (65.5%) eyes (29 non-proliferative including 6 with clinically significant macular oedema, and 9 proliferative). Progression of diabetic retinopathy to proliferative stage occurred in 7 eyes of 4 patients over a mean duration of 4.4 years. In 10 patients with active uveitis the mean HbA1c was 80 mmol/mol [9.5%], (range 49-137 [6.6-14.7]), and 67 mmol/mol [8.3%] (range 46-105 [6.4-11.8]) when the uveitis was quiescent, p = 0.01. Better glycaemic control was required in 10 patients during episodes of uveitis.

Conclusions

Patients with DM who develop uveitis may have a high complication rate, reduced vision and poor glycaemic control. Checking blood glucose during episodes of uveitis is important.

Exogenous endophthalmitis in diabetic patients: a systemic review

Diabetes mellitus is a systemic disease that increases the risk of infections. Exogenous endophthalmitis is an inflammatory disease to which diabetic patients are more predisposed to than nondiabetic patients undergoing any intraocular intervention. This might be because of the change in the immune and inflammatory factors that intervene in wound healing and in the bacterial flora of the ocular adnexa. We conducted a literature review to assess the risk of exogenous endophthalmitis in diabetic patients undergoing cataract extraction, pars plana vitrectomy, and intravitreal injections and to check whether its treatment differ from in non-diabetics. We found that diabetic patients are more predisposed to virulent organisms and that the incidence of ophthalmic symptoms was not substantially different in diabetic versus nondiabetic patients. Regarding treatment, all patients with light perception should receive pars plana vitrectomy, while those with hand motion and better vision should be given an intravitreal antibiotics injection. Some authors recommend vitrectomy to diabetic patients with even counting figure vision.

A role for excitatory amino acids in diabetic eye disease

Diabetic retinopathy is a leading cause of vision loss. The primary clinical hallmarks are vascular changes that appear to contribute to the loss of sight. In a number of neurodegenerative disorders there is an appreciation that increased levels of excitatory amino acids are excitotoxic. The primary amino acid responsible appears to be the neurotransmitter glutamate. This review examines the nature of glutamatergic signaling at the retina and the growing evidence from clinical and animal model studies that glutamate may be playing similar excitotoxic roles at the diabetic retina.

Rapid progression of diabetic retinopathy in eyes with posterior uveitis

PURPOSE

To report on two patients who developed rapid progression of asymmetric diabetic retinopathy (DRP) in eyes affected by posterior uveitis in contrast to their fellow eyes not affected by uveitis.

DESIGN

Observational case report.

METHODS

Two patients with diabetes mellitus (DM) and unilateral uveitis underwent repeated ophthalmologic examinations and fluorescein angiography.

RESULTS

Two patients with DM and unilateral posterior uveitis developed proliferative DRP in eyes with previous uveitis within 3 months after the uveitis subsided. In contrast, the retinal findings of nonuveitic eyes remained unchanged on follow-up of several years.

CONCLUSIONS

Since the pathogenesis of intraocular inflammation and diabetic retinopathy acts through similar biochemical mediators and pathways, it is feasible that posterior uveitis accelerates the progression of diabetic retinopathy. Our results support this hypothesis and point out a risk for rapid retinopathy development in eyes affected with posterior uveitis.

Diabetes and postcataract extraction endophthalmitis

This paper reports the results of an exploratory analysis among patients in the Endophthalmitis Vitrectomy Study to determine if there was a different response to treatment in diabetes and whether the signs and symptoms of endophthalmitis differ between diabetic and nondiabetic patients. Patients in this multicenter clinical trial were followed for 9 months after random assignment to either vitrectomy or tap/biopsy. Outcome measures included visual acuity assessed in standardized fashion. Fifty-eight of 420 study patients were diabetic. Diabetics presented with slightly worse vision and ocular media. Only 39% of diabetics compared with 55% of nondiabetics achieved 20/40 final vision. Both diabetic and nondiabetic patients who presented with vision of only light perception (LP) had better visual results with immediate vitrectomy. For those who presented with better than LP vision, diabetics achieved 20/40 more often with vitrectomy (57%) than with tap/biopsy (40%), but non diabetics did equally well with vitrectomy or tap/biopsy. In the diabetic group, small numbers did not allow adequate statistical power to test treatment difference. A new clinical trial is needed to determine if in fact there is a difference in response to treatment among diabetic and nondiabetic patients who present with better than LP vision.