Do optic neuritis patients report their visual impairment more frequently upon awakening?
Seyed Hossein Abtahi1 *, Masoud Etemadifar2 , Hamidreza Jahanbani-ardakari2
- Ophthalmic Research Center , Shahid Beheshti University of Medical Sciences; Tehran; Iran
- Isfahan University of medical sciences
Abstract: We frequently witnessed patients with Optic neuritis (ON) who noticed and reported their initial symptoms upon awakening in the morning. In this study, we evaluated such a diurnal pattern for onset of symptoms of ON.
Methods: In the study questionnaire, firstly, ON patients were asked for a simple question of ‘when you noticed it first’. The time by which the symptoms began was independent from the quality of symptoms. For analytic purposes, the 24 hours period was divided equally to bedtime (10 P.M. to 9 A.M.) and daytime (10 A.M. to 9 P.M.). Secondly, patients were meticulously asked for the nature of their symptoms.
Results: In this study, 50 patients (43 females and 7 males; age: 28.98±7.13 years) with newly diagnosed unilateral ON were questioned at Neuro-ophthalmology clinic of Feiz eye hospital, Isfahan, Iran. With regard to the first question, patients reported initiation of their symptoms more frequently during bedtime compared to daytime (35 vs. 15 patients; P <0.001, Chi2statistics). Of note, most of the patients with symptoms at bedtime reported that their visual symptoms initiated between 5 A.M. to 9 A.M. i.e. they noticed symptoms immediately upon waking in the morning.
Conclusion: To date, no diurnal pattern for onset of ON symptoms has been reported in the literature. As stated above, NAAION has a well-known similar pattern. Here, we showed that ON patients notify their onset symptoms more frequently upon waking in the morning. One may argue that after a longer period of sleep the awakening patient might perceive a sudden increase of symptomatic burden. This does not necessarily mean that the inflammatory process is initiated or evolves faster overnight. To answer, as it is clear, we divided 24 hours to two halves and the results were again in favor of notification of symptoms at the bedtime (10 P.M. to 9 A.M.).
Decrease in blood pressure during bedtime can precipitate a previously compromised disc. The process of ON evolves gradually in many cases and drop in blood pressure can deteriorate blood supply of an inflamed and compromised optic nerve.
