Bariatric Surgery Induces Retinal Thickening Without Affecting the Retinal Nerve Fiber Layer Independent of Diabetic Status

Towards precision medicine in bariatric surgery prescription

Obesity is a complex, multifactorial and chronic disease. Bariatric surgery is a safe and effective treatment intervention for obesity and obesity-related diseases. However, weight loss after surgery can be highly heterogeneous and is not entirely predictable, particularly in the long-term after intervention. In this review, we present and discuss the available data on patient-related and procedure-related factors that were previously appointed as putative predictors of bariatric surgery outcomes. In addition, we present a critical appraisal of the available evidence on which factors could be taken into account when recommending and deciding which bariatric procedure to perform. Several patient-related features were identified as having a potential impact on weight loss after bariatric surgery, including age, gender, anthropometrics, obesity co-morbidities, eating behavior, genetic background, circulating biomarkers (microRNAs, metabolites and hormones), psychological and socioeconomic factors. However, none of these factors are sufficiently robust to be used as predictive factors. Overall, there is no doubt that before we long for precision medicine, there is the unmet need for a better understanding of the socio-biological drivers of weight gain, weight loss failure and weight-regain after bariatric interventions. Machine learning models targeting preoperative factors and effectiveness measurements of specific bariatric surgery interventions, would enable a more precise identification of the causal links between determinants of weight gain and weight loss. Artificial intelligence algorithms to be used in clinical practice to predict the response to bariatric surgery interventions could then be created, which would ultimately allow to move forward into precision medicine in bariatric surgery prescription.

How Does Weight Loss After Bariatric Surgery Impact the Ocular Parameters? A Review

Our review aimed to assess the effects of bariatric surgery-induced weight loss on ocular functions. We focused on retinochoroidal microcirculation, glaucomatous factors, and the condition of the eye surface pre- and postoperatively. The review covered 23 articles, including five case reports. Bariatric surgery positively impacts retinochoroidal microcirculation. The arterial perfusion and vascular density improve, venules constrict, and the arteriole-to-venule ratio increases. Weight loss positively correlates with intraocular pressure decrease. The impact of postoperative weight loss on the choroidal thickness (CT) and the retinal nerve fiber layer (RNFL) is still unclear. The correlation between ocular symptoms and hypovitaminosis A needs to be evaluated. Further research is required, especially regarding CT and RNFL, mainly focusing on long-term follow-up.

Bariatric surgery-what the ophthalmologist needs to know

The incidence of bariatric surgery is increasing due to obesity being one of our top public health challenges. As such, bariatric-related ophthalmic changes are a potentially new clinical area of knowledge, with increasing published evidence on post-bariatric complications experienced by patients and identified by clinicians. We reviewed the available literature and summarised the different complications and potential recommendations. A search strategy was conducted with PubMed, Cochrane, Medline, Embase, Allied and Complementary Medicine and DH-DATA databases to look for papers answering our research question: "What are the ophthalmological complications for patients after bariatric surgery?". Our search gave a total of 59 relevant papers. Bariatric surgery, particularly subtypes that cause direct bypass of nutrients from the stomach, lead to nutritional deficiencies. Vitamin A, crucial for proper functioning of body systems and specialised cells, manifests ophthalmologically as corneal ulceration, nyctalopia, conjunctival xerosis and more. Thiamine levels are also depleted, leading to Wernicke's Encephalopathy. Pre-existing diabetic retinopathy is also noted to worsen sub acutely, although evidence is conflicting. Patients undergoing surgery to treat idiopathic intracranial hypertension would have reduced IOP and resolving papilloedema. Other comorbidities of obesity like HBA1C levels, obstructive sleep apnoea, and metabolic syndrome also resolve post-surgery. History taking remains the cornerstone of medical practice. From the evidence, we suggest consideration of pre-surgery screening for ophthalmic pathology and post-operative monitoring of disease progression. Real-world data needs to continuously be analysed to create definitive management pathways that can help clinicians recognise ophthalmic complications early, improving patient outcomes.

Evaluation of the alteration in retinal features following bariatric surgery in patients with morbid obesity

Aim: The aim of the study is to evaluate the effect of bariatric surgery on the retina and choroid in non-diabetic and non-hypertensive patients with morbid obesity using optic coherence tomography (OCT) retrospectively. Material and Method: Seventy-four eyes of seventy-four patients who have been underwent sleeve gasterectomy for morbid obesity in Balıkesir University Medicine Faculty & February 2019 and November 2020 were evaluated. All participants has a detailed ophthalmologic examination including best-corrected visual acuity (BCVA), intraocular pressure (IOP), slit-lamp biomicroscopy, retinal examination through non-dilated pupil via 90 D fundus lens, the retinal thickness (central, perifoveal, and parafoveal superior/nasal/inferior/temporal quadrants), and choroidal thickness through optic coherence tomography (RTVue XR Avanti, Optovue) in immediate preoperative and postoperative sixth-month. All values were compared. Results: The macular thickness was increased significantly in all quadrants in postoperative visits (p0.05). The correlation between preoperative BMI and preoperative choroidal thickness was significant (R: 0.416, p

Changes in the Macular Vascular Density After Bariatric Surgery Measured by Optical Coherence Tomography Angiography

Purpose

To evaluate the effect of the weight loss, 3 months after bariatric surgery, on the macular thickness and macular vascular density by optical coherence tomography angiography (OCTA).

Methods

Forty obese patients were included in this prospective study. Body mass index (BMI), macular thickness (whole, fovea, parafovea and perifovea), macular vascular density (VD) in superficial capillary plexus (whole, fovea, parafovea and perifovea), and macular vascular density in deep capillary plexus (whole, fovea, parafovea and perifovea) were measured before and 3 months after bariatric surgery.

Results

The BMI was significantly reduced postoperatively to 43.75±4.4 kg/m² compared to the preoperative results, 55.31±5.1 kg/m² (p<0.05). There was significant increase in macular thickness in the fovea and parafovea postoperatively (p<0.05) but no significant increase in the perifovea. There was significant increase in macular vascular density in the deep capillary plexus postoperatively (p<0.05) but no significant increase in the macular vascular density in the superficial capillary plexus postoperatively (p>0.05). Significant correlations were detected between the BMI changes and changes in different macular parameters.

Conclusion

Bariatric surgery showed significant effect on certain indices in macular thickness and macular vascular density, especially in the deep capillary plexus. Therefore, OCTA is considered a valuable tool to assess the short-term changes in macular microcirculation following significant weight reduction.