Latar Belakang: Pesawat terbang sekarang sudah canggih, dengan dilengkapi perangkat oksigen dan kabin bertekanan. Ketinggian jelajah pesawat terbang komersial berkisar antara 18.000-30.000 kaki, bahkan pesawat terbang militer bisa lebih tinggi, sehingga apabila terjadi kegagalan perangkat tersebut akan menyebabkan hipoksia. Manusia sangat peka terhadap kekurangan oksigen, terutama sel otak dan retina, maka bila terjadi kekurangan oksigen sedikit saja akan terjadi penyempitan penglihatan perifer yang merupakan gejala dini pada tubuh manusia. Hendarseto menyebutkan 84% subyek mengalami penyempitan penglihatan perifer 5° akibat pengaruh hipobarik dalam ruang udara bertekanan rendah (RUBR) setara ketinggian 18.000 kaki. Fungsi mata sangat penting dalam penerbangan, maka pengetahuan mengenai rentang waktu hipoksia awal yang ditandai dengan penyempitan penglihatan perifer sebesar 5° perlu diketahui dan diteliti. Metodologi: Disain penelitian ini adalah studi eksperimental, dengan memajankan sebanyak 94 talon penerbang PSDP TNI AU sebagai subyek dalam ruang udara bertekanan rendah (RIJBR) setara ketinggian 18.000 kaki, guna mengetahui hubungan kadar hemoglobin, kapasitas vital paksa, frekuensi denyut nadi ground level serta faktor faali tubuh lainnya dengan rentang waktu penyempitan penglihatan perifer sebesar 5°, sedang untuk analisis data digunakan analisis korelasi dan regresi linear. Hasil dan kesimpulan: Rata-rata rentang waktu penyempitan penglihatan perifer sebesar 5° (RWP5) ialah 201,85 detik dengan simpang baku 33,16 detik, 95% Cl: 195,15-208,55. Dari hasil analisis antara RWP5 dengan hemoglobin mempunyai korelasi positif dan bermakna (r= 0,62; p = 0,0000), 95% CI: 15,46-15,82, berarti makin tinggi kadar Hb akan semakin panjang RWP5. Antara RWP5 dengan KVP mempunyai korelasi positif dan bermakna (r= 0,16; p = 0,0164), 95% CI: 90,7-94,6, berarti makin tinggi KVP akan semakin panjang RWP5. Antara RWP5 dengan frekuensi denyut nadi ground level(GLNadi) mempunyai korelasi negatif dan bermakna ( r= - 0,28; p = 0,0000), 95% CI: 75,53-78,55, berarti makin tinggi GLNadi akan semakin pendek RWP5. Regresi metode stepwise yang sesuai untuk prediksi RWP5 terdin dan faktor hemoglobin, denyut nadi `ground level' dan kapasitas vital paksa, sedangkan variabel lain tidak berkorelasi dan tidak bermakna dengan RWP5.

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Background : The recent aircraft's technology is growing sophisticatedly, equipped with pressurized cabin and oxygen equipment. The cruising altitude of the commercial air line is in between 18.000 feet to 30.000 feet, although the military aircraft even higher. The human being are very sensitive to lack of oxygen, especially the brain cells and the retina, malfunction of cabin-pressure or oxygen equipment will cause a hypoxia and narrowing of peripheral vision is an early symptom. The eye have a very important role in flying, the research done by Hendarseto stated that 84% subjects experience narrowing the peripheral vision 5° or more due to hypoxia in hypobaric chamber. The elapsed time of an early hypoxia recognized by 5° narrowing of the peripheral vision should be explored.

Methodology : The research was designed as an experimental study, 94 PSDP Indonesian Air Force's pilot candidates (PSDP TNI AU), they were exposed in hypobaric chamber equal to 18.000 feet, measuring the elapsed time of 5° narrowing peripheral vision correlated with hemoglobin, forced vital capacity, pulse rate etc. Correlation analysis and linear analysis were used to analyze the data.

Results and Conclusion : The average elapsed time 5° narrowing of the peripheral vision (RWP5) is 201,85 seconds with standard deviation 33,16 second, 95% Cl : 195,15 - 208, 55. The analysis of the results of the relationship between RWP5 and hemoglobin had a positive correlation and statistically significance ( r = 0,62; p = 0,0000 ), 95% Cl: 15,46-15,82. It means that the higher the Hb concentration, the longer elapsed time 5° narrowing of the peripheral vision (RWP5). RWP5 and forced vital capacity (KVP) have positive correlation and statistically significant ( r = 0,16; p =0,0164 ), 95% Cl: 90,7-94,6 which means that the higher the forced vital capacity (KVP), the longer elapsed time 5° narrowing of the peripheral vision (RWP5). RWP5 and the frequency of ground level pulse rate (GLNadi) have negative correlation and statistically significance ( r = - 0,28; p = 0,0000 ), 95% CI: 75,53- 78,55 which means that the higher the frequency of ground level pulse rate (GLNadi), the shorter the elapsed time 5° narrowing of the peripheral vision (RWP5). Stepwise method of regression appropriate for RWP5 prediction consists of factors of hemoglobin, ground level pulse rate and forced vital capacity, other variables are not correlated and not significant related to RWP5.