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?AIM: To investigate the changes of nearwork induced transient myopia ( NITM ) in different refractive status after continuous near tasking.?METHODS:Prospective study. Thirty subjects ( aged 18-24, average 20. 9 ± 2. 1, 12 males and 18 females) were recruited in this study. They were divided into 3 groups according to the subjective refraction: 10 with hyperopia (H), 10 with emmetrope (E) and 10 with myopia (M). All the subjects with soft contact lens watched videos on a panel computer at near distance (33cm ~ 40cm). Five measurements of distance refraction in the right eye were performed by using an infrared optometer before, after 30min and 60min sustained viewing task, and the mean of 5 refractive values was recorded as spherical equivalent. Then distance refraction of right eyes was done every 5s followed by stopping near tasking until NITM was disappeared completely and the decay time of NITM was recorded for each subject. The value of NITM was the difference of refractive values between before and after near tasking. Paired-t test was used to compare the changes of refractive values in the same group. ANOVA was used to determine the differences of NITM and its decaying time among three groups.?RESULTS: Compared with pre - task, no significant refractive changes were found in hyperopic group ( t =1. 627,P= 0. 138 ); While subjects with emmetropia and myopia showed more myopic shifts at the two time points (tE = 2. 699, PE = 0. 024;tM = 4. 930, PM = 0. 001 ). With continuous viewing until the 30th min and 60th min, significant differences of averaged NITM were found between myopic group and other 2 groups (P0. 05). Significant differences of the decay time of NITM can be seen among the three groups after near tasking (F=787. 983,P<0. 001).? CONCLUSION: Subjects with myopia are more susceptible to produce NITM than other 2 groups during sustained nearwork for the same time and the decaying time of NITM is longer in myopia group after near tasking, thus it is suggesting that NITM might be attributed to the development and progression of myopia.
ABSTRACT
A 27-year-old woman developed bilateral acute angle closure glaucoma (AACG) and transient myopia after taking oseltamivir for four days. On the fourth day, she received systemic and topical intraocular pressure (IOP)-lowering agents, and IOP decreased in both eyes. However, her visual acuity was unchanged. A myopic shift of -5.25 D OD and -5.0 D OS was estimated to have occurred in the acute phase. A-scan ultrasonography and Pentacam showed markedly shallow anterior chambers and increased lens thickness. Ultrasound biomicroscopy revealed an annular ciliochoroidal effusion with forward displacement of the lens-iris diaphragm. Ciliochoroidal effusion and transient myopia were resolved after discontinuation of oseltamivir.
ABSTRACT
Background Epidemiologic studies found that the incidence of myopia is higher in Hong Kong and Taiwan regions of China than that of the mainland.So whether the general reading words with traditional Chinese characters and simplified characters is associated with myopia deserves attention.Objective This study was to test the accommodative responses and the regression levels of nearwork-induced transient myopia (NITM) induced by traditional complex Chinese characters and modern simplified ones in the same size,and to explore the differences and inherent relationship of the accommodative regulations based on the structures of the two types of Chinese character in causing reading triggered myopia.Methods Twenty two volunteers aged 24-29 years were included in this study with informed consent.The corrected vision of both eyes from each subject was ≥ 1.0 with a mean spherical equivalence of (-1.86±2.34)D.Accommodative response was tested with 4 different reading texts using the rapid sequence visual presenting model with the GRAND SEIKO-WV5500 infrared autorefractor,and this procedure was performed after full correction of refractive error.An initial test of looking at a certain distance was performed (as baseline),and then the subjects read intensively at the targets for 10 minutes at 33 cm to calculate the accommodative responses.After a 10 second pause,the ocular refractive status was obtained exactly at 15 seconds,20 seconds.The one-way ANOVA method was used to determine the effects of the different font types and sizes on the adjustive responses and the causation of NITM.Results Accommodative response induced by simplified and traditional Chinese characters showed an accommodative lag of (1.11 ±0.38),(0.95 ±0.43),(1.18 ±0.33) and (1.06±0.28) D,showing a significant difference among the 9 pt and 12 pt simplified and traditional Chinese characters (F =1.62,P =0.19),and significantly different accommodative lag values between 12 pt simplified characters and 9 pt traditional characters was found (t =5.56,P =0.02).NITM induced by the four different targets were (-0.45 ±0.45),(-0.47 ±0.46),(0.45 ±0.82) and (-0.46±0.78) D in the 4 types of characters,without a significant difference among them (F=0.01,P =0.99).Conclusions Near-distance reading causes accommodative lag regardless of the type of reading texts.The target demonstrated stimuli spatial frequency and font size play an impact on accommodative responses.NITM appears when one reads simplified or traditional Chinese for 10 minutes.The accommodative lag and NITM trend might be responsible for the onset or regression of myopia,yet it is not supportive for the hypothesis that reading traditional Chinese causes more strain since there is no difference between the two.
ABSTRACT
PURPOSE: To report a transient myopia with severe chemosis associated with systemic lupus erythematosus. METHODS: A 31-year-old woman was referred for decreased visual acuity of both eyes for 1 week. The patient came to the emergency medical center for facial edema and fever. She was examined and treated for systemic lupus erythematosus. Three years previously the patient underwent LASIK in both eyes, and maintained emmetropia postoperatively. RESULTS: At admission, spherical equivalent was -0.75D in the right eye and -6.5D in the left eye. On the 3rd day, the spherical equivalent was -11.0D in the right eye and -10.0D in the left eye and progressively decreased to -2.0D both eyes by the 12th hospital day. The mean corneal power was 39.8D in the right eye and 39.9D in the left eye on the 2nd hospital day and decreased to 38.8D in the right eye and 38.9D in the left eye by the 12th hospital day. The axial length change was not parallel with myopic changes. The anterior chamber depth was 2.14 mm in the right eye and 1.94 mm in the left eye on the 3rd hospital day and increased to 2.96 mm in the right eye and 2.84 mm in the left eye by the 12th hospital day. Under cycloplegic refraction, ciliary spasm was not evident. The bulbar conjunctivas were markedly chemotic on the 3rd hospital day, but after systemic steroid therapy the chemosis subsided and the conjunctivas became normal by the 12th hospital day. The patient was diagnosed with systemic lupus erythematosus and after medical treatment, was discharged from the hospital.
Subject(s)
Adult , Female , Humans , Anterior Chamber , Conjunctiva , Edema , Emergencies , Emmetropia , Fever , Keratomileusis, Laser In Situ , Lupus Erythematosus, Systemic , Myopia , Spasm , Visual AcuityABSTRACT
Although drug-induced transient myopia has been reported to be caused by the use of several drugs, it is very rare and the causes are still uncertain. A considerable literature has accumulated relating the occasional occurrence of myopia in patients receiving carbonic anhydrase inhibitors, especially acetazolamide. However the authors could not find any literature concerning transient myopia induced by dichlorphenamide. The authors reporthed here a case of transient myopia after dichlorphenamide in a patient with serous detachment of the macula with a review of the literatures.
Subject(s)
Humans , Acetazolamide , Carbonic Anhydrase Inhibitors , Dichlorphenamide , MyopiaABSTRACT
Although drug-induced transient myopia has been reported to be caused by the use of several drugs, it is very rare and the causes are still uncertain. A considerable literature has accumulated relating the occasional occurrence of myopia in patients receiving carbonic anhydrase inhibitors, especially acetazolamide. However the authors could not find any literature concerning transient myopia induced by dichlorphenamide. The authors reporthed here a case of transient myopia after dichlorphenamide in a patient with serous detachment of the macula with a review of the literatures.