Association of Dietary Vitamin K1 Intake With the Incidence of Cataract Surgery in an Adult Mediterranean Population: A Secondary Analysis of a Randomized Clinical Trial

Intraoperative quantitative crystalline lens nuclear opacities analysis based on crystalline lenSx platform

PURPOSE

The main objective is to quantify the lens nuclear opacity using spectral-domain optical coherence tomography (SD-OCT) and to evaluate its association with Lens Opacities Classification System III (LOCS-III) system, lens thickness (LT), and surgical parameters. The secondary objective is to assess the diagnostic model performance for hard nuclear cataract.

METHODS

This study included 70 eyes of 57 adults with cataract, with 49 (70%) and 21 (30%) in training and validation cohort, respectively. Correlations of the average nuclear density (AND) /maximum nuclear density (MND) with LOCS-III scores, LT, and surgical parameters were analyzed. Univariate and multivariate logistic regression analysis, receiver operating characteristic curves and calibration curves were performed for the diagnostic of hard nuclear cataract.

RESULTS

The pre-operative uncorrected distance visual acuity (UDVA), intraocular pressure (IOP), mean axial length (AL), and LT were 1.20 ± 0.47 log MAR, 15.50 ± 2.87 mmHg, 27.34 ± 3.77 mm and 4.32 ± 0.45 mm, respectively. The average nuclear opalescence (NO) and nuclear colour (NC) scores were 3.61 ± 0.94 and 3.50 ± 0.91 (ranging from 1.00 to 6.90), respectively. The average AND and MND were 137.94 ± 17.01 and 230.01 ± 8.91, respectively. NC and NO scores both significantly correlated with the AND (rNC = 0.733, p = 0.000; rNO = 0.755, p = 0.000) and MND (rNC = 0.643, p = 0.000; rNO = 0.634, p = 0.000). In the training cohort, the area under the curve (AUC) of the model was 0.769 (P < 0.001, 95%CI 0.620-0.919), which had a good degree of differentiation (Fig. 2a). The calibration curve showed good agreement between predicted and actual probability.

CONCLUSION

The nuclear density measurement on SD-OCT images can serve as an objective and reliable indicator for quantifying nuclear density.

A bibliometric and visualized analysis of the pathogenesis of cataracts from 1999 to 2023

Research on the pathogenesis of cataracts is ongoing and the number of publications on this topic is increasing annually. This study offers an overview of the research status, popular topics, and scholarly tendencies in the field of cataract pathogenesis over recent decades，which helps to guide future research directions, and optimize resource allocation. In the present study, we performed a bibliometric analysis of cataract pathogenesis. Publications from January 1, 1999, to December 20, 2023, were collected from the Web of Science Core Collection (WoSCC), and the extracted data were quantified and analyzed. We analyzed and presented the data using Microsoft Excel, VOSviewer, CiteSpace, and Python. In all, 4006 articles were evaluated based on various characteristics, including publication year, authors, countries, institutions, journals, citations, and keywords. This study utilized VOSviewer to conduct visualized analysis, including co-authorship, co-citation, co-occurrence, and network visualization. The CiteSpace software was used to identify keywords with significant bursts of activity. The number of annual global publications climbed from 76 to 277 between 1999 and 2023, a 264.47% rise. Experimental Eye Research published the most manuscripts (178 publications), whereas Investigative Ophthalmology & Visual Science received the most citations (6675 citations). The most influential and productive country, institution, and author were the United States (1244 publications, 54,456 citations), University of California system (136 publications, 5401 citations), and Yao Ke (49 publications, 838 citations), respectively. The top 100 ranked keywords are divided into four clusters through co-occurrence analysis: (1) secondary cataracts, (2) oxidative stress, (3) gene mutations and protein abnormalities, and (4) alteration of biological processes in lens epithelial cells. Further discussions on the four subtopics outline the research topics and trends. In conclusion, the specific mechanism of cataract formation remains a popular topic for future research and should be explored in greater depth.

Influence of Diet, Dietary Products and Vitamins on Age-Related Cataract Incidence: A Systematic Review

Cataract, defined as the opacification of the lens that prevents clear vision, is a leading cause of vision loss and impairment worldwide. Elderly people comprise the highest proportion of those suffering from this eye disease. According to the National Institute of Health (NIH), the risk of developing aged-related cataract (ARC) increases with every decade of life, starting from the age of 40. Despite progress in surgical treatment methods, life-style modifications may be beneficial in prevention or slowing down the progression of ARC. This systematic review aims to summarize studies on the significance of specific nutritional patterns, dietary products, vitamins, minerals, and carotenoids intake in the onset or progression of ARC. In this context, the presented paper thoroughly analyzes 24 articles, following the PRISMA guidelines. The results indicate significant protective effects of various dietary patterns, including the Korean balanced diet, vegetarian diet, "dairy products and vegetables", "traditional", "antioxidant", and "omega-3" patterns. Additionally, the consumption of fruits, vegetables, legumes, nuts, skimmed yoghurt, fish, coffee, and vitamins has shown positive effects on cataract incidence. Therefore, further research seems to be essential to gain a better understanding of these associations and to create uniform dietary recommendations for both the vulnerable population and ARC patients.

Vitamin K and the Visual System-A Narrative Review

Vitamin K occupies a unique and often obscured place among its fellow fat-soluble vitamins. Evidence is mounting, however, that vitamin K (VK) may play an important role in the visual system apart from the hepatic carboxylation of hemostatic-related proteins. However, to our knowledge, no review covering the topic has appeared in the medical literature. Recent studies have confirmed that matrix Gla protein (MGP), a vitamin K-dependent protein (VKDP), is essential for the regulation of intraocular pressure in mice. The PREDIMED (Prevención con Dieta Mediterránea) study, a randomized trial involving 5860 adults at risk for cardiovascular disease, demonstrated a 29% reduction in the risk of cataract surgery in participants with the highest tertile of dietary vitamin K1 (PK) intake compared with those with the lowest tertile. However, the specific requirements of the eye and visual system (EVS) for VK, and what might constitute an optimized VK status, is currently unknown and largely unexplored. It is, therefore, the intention of this narrative review to provide an introduction concerning VK and the visual system, review ocular VK biology, and provide some historical context for recent discoveries. Potential opportunities and gaps in current research efforts will be touched upon in the hope of raising awareness and encouraging continued VK-related investigations in this important and highly specialized sensory system.

Nutritional Strategies to Prevent Lens Cataract: Current Status and Future Strategies

Oxidative stress and the subsequent oxidative damage to lens proteins is a known causative factor in the initiation and progression of cataract formation, the leading cause of blindness in the world today. Due to the role of oxidative damage in the etiology of cataract, antioxidants have been prompted as therapeutic options to delay and/or prevent disease progression. However, many exogenous antioxidant interventions have to date produced mixed results as anti-cataract therapies. The aim of this review is to critically evaluate the efficacy of a sample of dietary and topical antioxidant interventions in the light of our current understanding of lens structure and function. Situated in the eye behind the blood-eye barrier, the lens receives it nutrients and antioxidants from the aqueous and vitreous humors. Furthermore, being a relatively large avascular tissue the lens cannot rely of passive diffusion alone to deliver nutrients and antioxidants to the distinctly different metabolic regions of the lens. We instead propose that the lens utilizes a unique internal microcirculation system to actively deliver antioxidants to these different regions, and that selecting antioxidants that can utilize this system is the key to developing novel nutritional therapies to delay the onset and progression of lens cataract.

Nutritional effect on age-related cataract formation and progression

PURPOSE OF REVIEW

To provide a comprehensive summary of the latest evidence-based data on nutrients linked to the pathogenesis of cataract formation and progression.

RECENT FINDINGS

This summary of peer-reviewed publications emphasizes the ongoing effort to modulate the cataractogenous process through nutrition, and points at an only weak evidence for the contribution of a specific nutrient to this process. Although observational studies successfully demonstrated a positive correlation between specific nutrients intake and age-related cataract, such evidence was usually lacking in following interventional studies. Three metanalyses point towards a beneficial effect of high intake of vitamin C, vitamin E and vitamin A on the risk of age-related cataract. New studies point at a protective effect of a high intake of vitamin K1 and vitamin D but negate the influence of Mediterranean diet or an overall high dairy consumption on the progression of cataract in a subgroup of patients. Sterols are candidate nutrients for future investigation.

SUMMARY

Nutrition rich in fruits and vegetables, and a high dietary intake of vitamins A, C, D, E and K1 may be inversely associated with the risk of age-related cataract. More studies involving patients in a wide range of nutritional status are required to establish the long-term benefit of nutritional supplements.