Visual function in patients undergoing long-term total parenteral nutrition.

Area of Science:

• Ophthalmology
• Nutritional Science
• Clinical Medicine

Background:

• Long-term total parenteral nutrition (TPN) is a critical intervention for patients unable to absorb nutrients enterally.
• Potential ocular side effects of TPN are not fully understood, necessitating investigation into its long-term impact on visual health.

Purpose of the Study:

• To assess the long-term effects of TPN on ocular function in both pediatric and adult populations.
• To identify potential correlations between specific nutrient levels and observed visual function abnormalities.

Main Methods:

• Ophthalmoscopic examinations and visual-function testing were performed on 27 adults and 12 children receiving TPN.
• Blood nutrient levels (including vitamins A, E, zinc, selenium, fatty acids, and taurine) were analyzed.
• Electroretinograms (ERGs) were used to evaluate retinal function.

Main Results:

• Funduscopic examination revealed retinal pigmented epithelium granularity in some patients.
• Abnormalities in electroretinograms were detected in approximately half of the children and one-third of the adults.
• Low concentrations of selenium, linoleic/linolenic acids, and taurine were noted, while Vitamin A was elevated in some adults.
• Only zinc and vitamin E levels showed a significant correlation with visual function indices.

Conclusions:

• Long-term TPN is associated with ocular abnormalities, including retinal changes and electroretinogram impairments.
• While various nutrient imbalances occur during TPN, zinc and vitamin E appear to be key factors influencing visual function.
• Further research is warranted to optimize TPN protocols for preserving ocular health.