The Effect on the Dryness of Eye during VDT Work

The ocular symptoms of visual display terminal (VDT) syndrome are caused by asthenopia, electromagnetic waves, and eye fatigue. To find out what cause make the fatigue of eye during VDT work, we measured frequency of blinking and height of palpebral fissure at near, reading a book, and during VDT work. Tear film break-up time(BUT) was measured immediately after the VDT work and during reading a book. The frequency of blinking during VDT work and book reading decreased significantly comparing with the one at rest (p<0.01). The average frequency of blinking is 20.52 +/- 5.89/min at rest, 8.29 +/- 4.15/min at VDT work, and 10.31 +/- 5.48/min at reading. The BUT measured immediately after VDT work decreased much more than in the resting state (p<0.01). The average BUT was 11.52 +/- 3.41sec at rest and 6.18 +/- 2.65sec immediately after VDT work. The height of palpebral fissure during VDT work increased significantly comparing with the value at rest (p<0.01). The average height of palpebral fissure was 7.39 +/- 0.78mm at rest and 8.83 +/- 0.75mm during VDT work. This study reveals the fatigue of eye during VDT work was induced by the dryness of eye resulted from the increased evaporation due to the decrement in the frequency of blinking and the widening of palpebral fissure. To prevent the fatigue of eye caused by dryness during VDT work, it is important for VDT workers to intend to blink frequently, place VDT lower than eye level to reduce the height of palpebral fissure, humidify the room adequately, put artificial eye tear in eye frequently, and take a rest after 20 mimutes work at least.

Study on Axial Length and Refractive Error in Unilateral Congenital Ptosis

We conducted a prospective study of 30 cases which had unilateral congenital blepharoptosis on visual acuity, refractive error, degree of ptosis, levator function, axial length and stereoacuity. A comparison of visual acuity between ptotic and healthy eyes revealed a reduction of visual acuity, but nearly same incidence of myopia in the ptotic eyes. But astigmatism in the ptotic eye was shown higher incidence with a borderline statistic significance(healthy eye 7/30, ptotic eye 14/30, p=0.056). Axial length for ptotic eyes was longer than healthy eye with statistic significance (22.80 +/- 1.46 vs 22.64 +/- 1.40mm, p=0.029). Strabismus was found in 4 cases; of them, 3 exotropia and remaining 1 hypertropia. Stereoacuity was more than 80 seconds except 7 cases which were amblyopic case. We concluded that in case of unilateral congenital ptosis, axial length was longer than healthy eye but incidence of myopia was nearly similar.

Two Cases of Anterior Segment Ischemia After Strabismus Surgery

Anterior segment ischemia(ASI) may be caused by a detachment of the rectus muscles from the globe. The interruption of the anterior ciliary artery by the detachment of rectus muscles causes a subsequent hypoperfusion to the anterior segment. ASI occurs more easily after surgery on the vertical rectus or after detachments of two or more adjacent rectus muscles. We experienced two patients with ASI after performing muscle surgery on them for lateral rectus muscle palsy caused by a traffic accident. A 5-year-old-male developed keratitis and uveitis following a Hummelsheim operation in combination with a lateral rectus resection in his right eye. A 51-year-old female showed keratitis, uveitis and pupilary distortion after a Knapp procedure combined with a lateral rectus tucking in her right eye. Both patients recovered without any complications.

A case of Retinal Vascular Disease in Ulcerative Colitis

Ulcerative colitis(UC) is a form of inflammatory bowel disease of unknown causes developing local and systemic complications. Various ocular abnormalities arise in patients with UC. But there have been few reported cases of retinal vascular disease in conjunction with UC. We experienced a 32-year-old male UC patient who developed nonischemic central retinal vein occlusion. We think that this complication is most likely due to vasculitis involving the disc.