Asthenopia: Diagnosis, Tatalaksana, Terapi

Asthenopia (kelelahan mata) merupakan sekumpulan gejala berupa permasalahan pada penglihatan (visual), mata (okular), dan muskuloskeletal yang umumnya terjadi hilang timbul. Keluhan ini sering muncul akibat pengaruh penggunaan perangkat digital dalam waktu yang lama terutama lebih dari 6 jam perhari. Penderita asthenopia secara global mencapai 60 juta orang yang didominasi usia muda. Gejala asthenopia yang paling sering dirasakan adalah keluhan mata kering, kesulitan dalam memfokuskan objek, mata tegang, mata lelah, dan sakit kepala. Diagnosis asthenopia dapat dilakukan secara subjektif dengan menggunakan kuesioner standar ataupun secara objektif dengan pemeriksaan lanjutan. Pemeriksaan yang dapat dilakukan berupa pengukuran Critical Flicker-fusion Frequency (CFF), pengukuran frekuensi berkedip, kemampuan akomodasi, serta refleks cahaya dan ukuran pupil yang dapat memberikan gambaran lebih jelas ke arah asthenopia. Tatalaksana dan terapi pada asthenopia diberikan untuk meredakan gejala dan mengatasi penyebabnya seperti terapi untuk mengatasi mata kering, koreksi gangguan refraksi, terapi gangguan akomodasi dan vergensi, dan penggunaan kacamata filter cahaya biru. Walaupun asthenopia terjadi secara hilang timbul, penyakit ini dapat menjadi menetap dan berkembang menimbulkan keluhan permanen. Artikel ini ditulis berdasarkan hasil literature review dari penelitian terkait diagnosis, tatalaksana, dan terapi asthenopia yang sudah dipublikasi. Penulisan artikel ini diharapkan dapat dijadikan acuan dalam menindaklanjuti kasus asthenopia sehingga prevalensi dan insidensinya dapat ditekan.

Critical Flicker Fusion Frequency: A Narrative Review

This review presents the current knowledge of the usage of critical flicker fusion frequency (CFF) in human and animal model studies. CFF has a wide application in different fields, especially as an indicator of cortical arousal and visual processing. In medicine, CFF may be helpful for diagnostic purposes, for example in epilepsy or minimal hepatic encephalopathy. Given the environmental studies and a limited number of other methods, it is applicable in diving and hyperbaric medicine. Current research also shows the relationship between CFF and other electrophysiological methods, such as electroencephalography. The human eye can detect flicker at 50–90 Hz but reports are showing the possibility to distinguish between steady and modulated light up to 500 Hz. Future research with the use of CFF is needed to better understand its utility and application.

Effect of abacus training on critical flicker fusion frequency threshold among primary schoolchildren

Objectives: The concept of neuronal plasticity has been considerably studied to know how long-lasting changes are associated with brain’s capacity to be shaped or sculptured by experience. Potential cognitive benefits of abacus training have been proved by various studies indicating it to be a promising tool in improving cognitive abilities including arithmetic abilities, visuospatial and working memory. Critical flicker fusion happens when the individual can no longer differentiate between changing visual stimuli. It can be modulated by behavioural or psychophysical techniques. The objectives of the study were to evaluate the effects of abacus training on critical flicker fusion frequency (CFFF) threshold. Materials and Methods: CFFF threshold (CFFFT) was measured in 60 school students studying third and fourth standard (30 trained in abacus and 30 not trained in abacus) using portable software-based apparatus. Results: The mean scores of abacus trained individuals were significantly higher compared to those who were not trained. Conclusion: Since higher CFFFTs can absorb more visual information, increasing their threshold might lead to cognitive improvement and better academic performance. Abacus trained individuals showed significantly higher critical fusion frequency threshold.

Investigating critical flicker fusion frequency for monitoring gas narcosis in divers

(Vrijdag XCE, van Waart H, Sleigh JW, Balestra C, Mitchell SJ. Investigating critical flicker fusion frequency for monitoring gas narcosis in divers. Diving and Hyperbaric Medicine. 2020 December 20;50(4):377–385. doi: 10.28920/dhm50.4.377-385. PMID: 33325019.) Introduction: Critical flicker fusion frequency (CFFF) has been used in various studies to measure the cognitive effects of gas mixtures at depth, sometimes with conflicting or apparently paradoxical results. This study aimed to evaluate a novel automatic CFFF method and investigate whether CFFF can be used to monitor gas-induced narcosis in divers. Methods: Three hyperbaric chamber experiments were performed: 1) Automated and manual CFFF measurements during air breathing at 608 kPa (n = 16 subjects); 2) Manual CFFF measurements during air and heliox breathing at sea level (101.3 kPa) and 608 kPa (n = 12); 3) Manual CFFF measurements during oxygen breathing at sea level, 142 and 284 kPa (n = 10). All results were compared to breathing air at sea level. Results: Only breathing oxygen at sea level, and at 284 kPa, caused a significant decrease in CFFF (2.5% and 2.6% respectively compared to breathing air at sea level. None of the other conditions showed a difference with sea level air breathing. Conclusions: CFFF did not significantly change in our experiments when breathing air at 608 kPa compared to air breathing at sea level pressure using both devices. Based on our results CFFF does not seem to be a sensitive tool for measuring gas narcosis in divers in our laboratory setting.