Reduction of intraocular pressure after bariatric surgery

Incidence of ocular pathology following bariatric surgery for with morbid obesity across a large United States National Database

BACKGROUND/OBJECTIVES

Bariatric surgery, as indicated for treatment of morbid obesity, has been studied in association with short term effects on ocular pathology. However, effects of surgery on postoperative disease incidence is largely unknown.

SUBJECTS/METHODS

In this retrospective cohort study, the TriNetX United States Collaborative Network national database, was queried for patients with an ICD-10 code for morbid obesity and a procedural code for bariatric surgery. Patients were propensity score matched across baseline demographics at the time of surgery and compared to those presenting with an ICD10 code for morbid obesity with no records of a procedural code for bariatric surgery, identifying 42,408 patients per cohort. New diagnoses or procedural codes found after the surgical index date for diabetic retinopathy, age-related macular degeneration, glaucoma, low vision, and blindness along with pertinent treatment metrics were monitored.

RESULTS

Bariatric surgery was found to be associated with reduced future risk of diabetic retinopathy (RR: 0.283; 95% CI: 0.252-0.319), macular edema (RR: 0.224; 95% CI: 0.170-0.297), vitreous hemorrhage (RR: 0.459; 95% CI: 0.323-0.653), ocular hypertension (RR: 0.387; 95% CI: 0.387-0.487), glaucoma (RR: 0.360; 95% CI: 0.326-0.399), use of ocular pressure lowering medications (RR: 0.565; 95% CI: 0.496-0.644), age-related macular degeneration (RR: 0.628; 95% CI: 0.447-0.882), cataract surgery (RR: 0.524; 95% CI: 0.448-0.612), and low vision and blindness (RR: 0.328; 95% CI: 0.294-0.365) compared to patients not surgically managed.

CONCLUSIONS

The present analysis comprising a large US cohort of patients suggests that bariatric surgery is associated with a decreased risk of future ocular morbidity and mortality.

Evaluating the impact of caloric restriction, body mass index and exercise on primary open-angle glaucoma: A review

This literature review evaluates any possible links between primary open-angle glaucoma (POAG) and caloric restriction (CR), body mass index (BMI), and exercise, aiming to map the extent of the literature. Its primary objective is to recognise the nature and breadth of research evidence, identify possible gaps in these topics and develop future studies. The databases searched were MEDLINE (PudMed), Scopus and ScienceDirect, in April 2023 for articles published in English, with no date restriction. A total of 447 search results were retrieved. Of these, 73 were related to CR, 249 to BMI, and 125 to exercise. Records identified included systematic reviews, meta-analyses, randomised controlled trials, cohort studies and animal studies. CR has been shown to halt the degeneration of retinal ganglion cells and protect against various glaucomatous processes in animal models. Low BMI has been shown to be associated with an increased risk of POAG and a faster rate of visual field deterioration in POAG. However, the association between high BMI and POAG is not consistent. Exercise has been shown to cause mechanical, vascular, and neurobiological changes affecting the pathophysiology of POAG. The present review helps identify key characteristics and factors relating to the impacts of CR, BMI, or exercise on POAG.

Impact of obesity on peripapillary choroidal thickness, macular choroidal thickness, and lamina cribrosa morphology

BACKGROUND

Obesity is known to be a significant risk factor for many ocular diseases. In order to understand the mechanism of obesity-related ocular diseases, we examined the lamina cribrosa morphology, peripapillary choroidal thickness (PPCT), and macular choroidal thickness (MCT) in obese women using optical coherence tomography (OCT).

METHODS

This comparative cross-sectional study included the right eyes of 72 obese women and 63 healthy women classified based on body mass index (BMI). Each participant underwent a thorough ophthalmological examination and enhanced depth (EDI) OCT imaging, including measurements of PPCT from a total of 12 regions, MCT from a total of 7 regions, Bruch's membrane opening (BMO), lamina cribrosa thickness (LCT), lamina cribrosa depth (LCD), intraocular pressure (IOP), and central corneal thickness (CCT).

RESULTS

The mean age and BMI of the obese group were 32.36±7.38 years and 35.11±4.39 kg/m², while those of the control group were 31.64±7.78 years and 20.88±1.72 kg/m² (p = 0.658, and p<0.001, respectively). PPCT N1000, PPCT N1500, PPCT S1500, and PPCT T1500 were statistically significantly thinner in the obese group than the control group (p values were 0.039, 0.012, 0.027, and 0.036, respectively). IOP and CCT were significantly higher in the obese group than the control group (p = 0.016, and p = 0.019, respectively). There was no statistically significant difference between the two groups in terms of MCT, BMO, LCT, and LCD.

CONCLUSION

We discovered thinning in the PPCT, which indicates microvascular abnormalities in the optic disc head. Microvascular alteration in the peripapillary region may be a potential initial event in the pathogenesis of several obesity-related ocular diseases, especially glaucoma.

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.

Phenotypic and Genetic Links between Body Fat Measurements and Primary Open-Angle Glaucoma

The phenotypic and genetic links between body fat phenotypes and primary open-angle glaucoma (POAG) are unclear. We conducted a meta-analysis of relevant longitudinal epidemiological studies to evaluate the phenotypic link. To identify genetic links, we performed genetic correlation analysis and pleiotropy analysis of genome-wide association study summary statistics datasets of POAG, intraocular pressure (IOP), vertical cup-to-disc ratio, obesity, body mass index (BMI), and waist-to-hip ratio. In the meta-analysis, we first established that obese and underweight populations have a significantly higher risk of POAG using longitudinal data. We also discovered positive genetic correlations between POAG and BMI and obesity phenotypes. Finally, we identified over 20 genomic loci jointly associated with POAG/IOP and BMI. Among them, the genes loci CADM2, RP3-335N17.2, RP11-793K1.1, RPS17P5, and CASC20 showed the lowest false discovery rate. These findings support the connection between body fat phenotypes and POAG. The newly identified genomic loci and genes render further functional investigation.

A Glaucoma Patient with an Intraocular Pressure Decrease following Total Gastrectomy and Postoperative Anticancer Treatment

We herein report a case of glaucoma with an intraocular pressure (IOP) decrease following total gastrectomy (TG) and anticancer treatment for gastric cancer. A 62-year-old male underwent trabeculectomy of the left and right eyes in August 2011 and July 2012, respectively. During the follow-up, IOP of the right eye was 9-12 mmHg (with bimatoprost, dorzolamide, and timolol maleate), and that of the left eye ranged between 14 and 26 mmHg (with bimatoprost, dorzolamide, timolol maleate, and brimonidine tartrate). In December 2014, TG was performed due to gastric cancer. After surgery, the patient received S-1+CDDP, weekly PAC, and CPT-11 therapies. The patient died on March X, 2017. Before TG, the body mass index (BMI) was 29.5 but decreased to 24.8 before the start of the two courses of weekly PAC therapy. IOP of the right eye was 6 mmHg (with bimatoprost), and that of the left eye was 10 mmHg (with bimatoprost, dorzolamide, and brimonidine tartrate), showing decreases. After the initiation of weekly PAC therapy, BMI was approximately 19. IOP of the right eye ranged between 6 and 10 mmHg until the final ophthalmological examination (January 11, 2017), while that of the left eye ranged between 8 and 15 mmHg. In this patient with glaucoma, IOP was not controlled by eye drop treatment, and TG for gastric cancer and postoperative treatment with anticancer drugs resulted in weight loss and a decrease in IOP.

The effect of body mass index reduction on intraocular pressure in a large prospective cohort of apparently healthy individuals in Israel

PURPOSE

To investigate the effect of change in body mass index (BMI) on intraocular pressure (IOP) in a large cohort of apparently healthy volunteers who underwent an annual comprehensive screening examinations.

METHODS

This study included individuals who were enrolled in the Tel Aviv Medical Center Inflammation Survey (TAMCIS) and had IOP and BMI measurements at their baseline and follow up visits. Relationships between BMI and IOP and the effect of change in BMI on IOP were investigated.

RESULTS

A total of 7,782 individuals had at least one IOP measurement at their baseline visit, and 2,985 individuals had ≥2 visits recorded. The mean (SD) IOP (right eye) was 14.6 (2.5) mm Hg and mean (SD) BMI was 26.4 (4.1) kg/m2. IOP positively correlated with BMI levels (r = 0.16, p<0.0001). For individuals with morbid obesity (BMI≥35 kg/m2) and ≥2 visits, a change in BMI between the baseline and first follow-up visits correlated positively with a change in the IOP (r = 0.23, p = 0.029). Subgroup analysis of subjects who had a reduction of at least 2 BMI units showed a stronger positive correlation between change in BMI and change in IOP (r = 0.29, p<0.0001). For this subgroup, a reduction of 2.86 kg/m2 of BMI was associated with a reduction of 1 mm Hg in IOP.

CONCLUSIONS

BMI loss correlated with reduction in IOP, and this correlation was more pronounced among morbidly obese individuals.

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.

The Correlation Between Body Weight and Intraocular Pressure

INTRODUCTION: Preflight body weight is a strong predictor of visual changes in spaceflight. To understand the effect of body weight on the eye, we examined the effect of increased body mass index on intraocular pressure on Earth.METHODS: We conducted a systematic review to summarize the relationship between weight parameters (including body mass index (BMI) and obesity indices), and intraocular pressure (IOP). Study selection and data extraction were performed in duplicate using EMBASE, MEDLINE, and CENTRAL, from database inception to the second week of April 2020.RESULTS: A total of 66 individual studies were included for qualitative analysis from the 1364 studies eligible for title and abstract screening. A total of 39 studies were available for quantitative analysis. The average BMI was 25.9 (range, 20.148.8) and the average IOP was 14.9 mmHg (range, 11.627.8). The overall pooled RR between BMI and elevated intraocular pressure (IOP) was 1.06 (95 CI%, 1.041.07), meaning for each unit increase in BMI one is 6 more likely of having higher IOP than baseline. Two studies assessed the effects of bariatric surgery, and both showed significant decreases in IOP postoperatively.CONCLUSION: A higher BMI was associated with increased IOP in ground-based studies. IOP also decreased with weight loss. These data support the idea that alterations in body weight affect intraocular pressures. Further research is needed to understand the relationship between body weight, IOP, and microgravity-induced visual changes. This finding may also be useful clinically.Khan S, Kirubarajan A, Lee M, Pitha I, Buckey JC Jr. The correlation between body weight and intraocular pressure. Aerosp Med Hum Perform. 2021; 92(11):886-897.

Short-term effect of weight loss after bariatric surgery on IOP, RNFL thickness, and the optic nerve head blood flow measured by OCTA

PURPOSE

To study the influence of weight reduction after bariatric surgery on the intraocular pressure (IOP), retinal nerve fiber layer (RNFL) thickness, and blood flow of optic nerve head by optical coherence tomography angiography (OCTA).

METHODS

This prospective observational cohort study included 60 obese patients. Body mass index (BMI), IOP, RNFL, and ganglion cell complex (GCC) thickness, rim area, and radial peripapillary capillary (RPC) vessel density were assessed before and 3 months after bariatric surgery.

RESULTS

The BMI and the IOP showed significant postoperative reduction to 40.45 ± 4.3 kg/m² and 14.83 ± 2.5 mmHg while the preoperative results were 51.13 ± 4.83 kg/m² and 16.95 ± 4.2 mm (p < 0.0001), respectively. No statistically significant change was detected in the RNFL, GCC thickness, rim area, or the RPC vessel density (p > 0.05). No statistically significant correlation was detected between the BMI changes and changes in the IOP, RNFL thickness, rim area, GCC thickness, or RPC vessel density.

CONCLUSION

No significant effect of bariatric surgery on the RNFL thickness and the optic nerve head blood flow measured by OCTA despite a significant IOP reduction 3 months post-surgical. OCTA can be a useful tool to assess the short-term influence of significant weight reduction on the retinal microcirculation.

SUMMARY

Despite a significant BMI and IOP reduction following bariatric surgery in obese patients, the vascular flow of the ONH, measured by OCTA, and the RNFL thickness were not significantly affected. The former might be attributed to the complex autoregulatory mechanisms related to the ONH and its microcirculation.

Non-drug interventions in glaucoma: Putative roles for lifestyle, diet and nutritional supplements

Glaucoma is a major ocular neurodegenerative disease characterized by progressive retinal ganglion cells degeneration and sight loss. Current treatment options have been limited to reducing intraocular pressure (IOP), known as the leading risk factor for this disease; however, glaucoma can develop even with low or normal IOP and progress despite controlling IOP values. Lifestyle, dietary habits, and supplementation may influence some of the risk factors and pathophysiological mechanisms underlying glaucoma development and progression; thus, the role of this complementary and alternative medicine in glaucoma has received great interest from both patients and ophthalmologists. We provide a summary of the current evidence concerning the relationship between lifestyle, dietary habits, and effects of supplements on the incidence and progression of glaucoma and their targets and associated mechanisms. The data suggest the existence of a therapeutic potential that needs to be further explored with both preclinical and rigorous clinical studies.

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.

Evaluation of the choroidal thickness and retinal nerve fiber layer and visual fields in morbid obesity: Does bariatric surgery affect retinal structure and function?

Purpose

The study aimed to investigate the changes in choroidal thickness (CT), retinal nerve fiber layer thickness (RNFL), and visual field parameters in morbidly obese patients following bariatric surgery.

Methods

The study included 40 morbidly obese patients with body mass indexes (BMI) ≥40 who had undergone bariatric surgery (Group 1) and 40 age-and sex-matched healthy subjects with normal BMI values (Group 2). RNFL and CT measurements by optical coherence tomography (OCT) and visual field test were performed preoperatively and the 1^st, 6^th, and 12th months postoperatively. CT measurements were obtained from the subfoveal, nasal (N), and temporal (T) regions at distances of 500 μm and 1,000 μm from the fovea.

Results

No significant pathology was detected during ophthalmological examinations following bariatric surgery. The BMIs were found to be significantly lower in all of the periods after bariatric surgery (P < 0.0001). The CT measurements decreased significantly in all periods after bariatric surgery (P < 0.0001). No differences were found in terms of the mean RNFL thicknesses in all postoperative periods (P = 0.125). Visual field tests showed no significant changes during scheduled visits. (P = 0.877). No visual field defect was detected in any patient during the follow-up periods after bariatric surgery.

Conclusion

These results have suggested that CT is positively correlated with BMI and decreased with a reduction in BMI progressively. Nutritional disorders resulting from malabsorption have not caused any nutritional optic neuropathy and visual field defect for at least the first postoperative year after bariatric surgery.

Does Bariatric Surgery Affect Intraocular Pressure?

PURPOSE

The effect of body mass index (BMI) reduction following bariatric surgery on intraocular pressure (IOP) is not well established. We evaluated association between BMI reduction and IOP measurements and other ocular and metabolic parameters 1 year after bariatric surgery.

MATERIALS AND METHODS

A retrospective study with over 1-year follow-up on patients who underwent weight reduction bariatric surgery between January 2016 and December 2016 at Wolfson Medical Center, Israel. Patient data was extracted from outpatient's bariatric and ocular clinic records. Metabolic, ocular, and clinical parameters were assessed including BMI changes, IOP, central corneal and retinal nerve fiber layer thickness, optical coherence tomography, and biometry results.

RESULTS

Of 22 bariatric surgery patients, 15 underwent laparoscopic sleeve gastrectomy (LSG) and 7 laparoscopic mini gastric bypass (MGB). All were followed up for over 1 year after surgery. Average BMI decreased from 41.9 ± 7.3 to 25.5 ± 5.7 kg/m² at 1-year follow-up (p < 0.001). Mean IOP decreased significantly by 21% after 1 year (p < 0.001). Decrease in IOP 1 year after surgery was correlated with decrease in IOP at 3-month follow-up (r = 0.677, p = 0.001), preoperative IOP (r = 0.837, p < 0.001), and corneal thickness (r = 0.589, p = 0.006), with no correlation between reduction in IOP and baseline weight, BMI, or the reduction in either (p > 0.05). Central corneal thickness and retinal nerve fiber layer thickness were also significantly decreased (p = 0.038) and (p = 0.018), respectively.

CONCLUSION

BMI reduction achieved by bariatric surgery was associated with significant and continued decline in IOP beyond 1 year after surgery. Clinical implications highlight the importance of considering bariatric surgery in patients with ocular hypertension.

Ophthalmologic evaluation of severely obese patients undergoing bariatric surgery: A pilot, monocentric, prospective, open-label study

Purpose

The aim of this study was to investigate the pathogenic role of obesity on blinding eye diseases in a population of severely obese patients with no history of eye diseases, and to verify whether weight loss induced by bariatric surgery may have a protective effect.

Methods

This was a pilot, monocentric, prospective, and open label study conducted at the University Hospital of Pisa. Fifty-seven severely obese patients with a mean body mass index value of 44.1 ± 6 kg/m² were consecutively recruited and received a complete ophthalmological evaluation and optical coherence tomography. Twenty-nine patients who underwent gastric bypass were evaluated also 3 months, and 1 year after surgery.

Results

At baseline, blood pressure value were directly and significantly related to intraocular pressure values (p<0.05, R = 0.35). Blood pressure values were also significantly and inversely related to retinal nerve fiber layer thickness, particularly in the temporal sector (RE p<0.05 r-0.30; LE p<0.01, R = -0.43). Moreover, minimum foveal thickness values were significantly and inversely associated with body mass index (RE p<0.02, R = -0.40; LE p<0.02, R = -0.30). A significant reduction of body mass index (p<0.05) and a significant (p<0.05) improvement of blood pressure was observed three months and one year after gastric bypass, which were significantly associated with an increase in retinal nerve fiber layer thickness and minimum foveal thickness values in both eyes (p<0.05).

Conclusions

The results of this study suggest that obese patients may have a greater susceptibility to develop glaucomatous optic nerve head damage and age-related macular degeneration. Moreover, weight reduction and improvement of comorbidities obtained by bariatric surgery may be effective in preventing eye disease development by improving retinal nerve fiber layer and foveal thickness.