Prediction of Visual Acuity in Macular Disease Using Hand-held Laser Interferometer

To evaluate the predictability of visual outcome in vaculopathy patients after treatment, we compared the difference between the pre-treatment visual acuity measured by hand-held laser interferometer and the posttreatment corrected visual acuity using Han`s visual acuity chart. Disease distribution was as follows; BRVO(18 cases), CRVO(11 cases), CSCR(9 cases), posterior uveitis(4 cases). The mean up period was 3.45 months. Among 42 cases, 28 eyes showed positive disparity and 13 eyes showed negative disparity. The range of disparity was from -0.2 to +0.3(mean 0.113). The post-treatment visual acuity was predictable within 2 lines in 38 eyes(90%) We concluded that the hand-held laser interferometer is one of the reliable methods to predict the post-treatment visual acuity in maculopathy patients.

The Predictability of Laser Interferometer on Postoperative Visual Outcome in Complicated Cataracts

The potential visual acuity predicted by the laser interferometer (LI) was compared with the postoperative best corrected visual acuity (BCVA) measured by Hans visual acuity chart in 30 eyes of 28 patients with diabetes mellitus (group 1) and 36 eyes of 35 patients with previous retinal surgery or other ocular disease (group 2) to determine the predictive accuracy of LI in complicated cataracts. 55 eyes of 51 patients without diabetes mellitus or any other ocular diseases were served as control. In control group, the LI closely estimated (in the range of +/-25%) postoperative BCVA in 33 eyes (60%), underestimated in 15 eyes (27%), and overestimated in 7 eyes (13%). In group 1, the LI closely estimated in 16 eyes (54%), underestimated in 10 eyes (33%), and overestimated in 4 eyes (13). In group 2, the LI closely estimated in 16 eyes (45%), underestimated in 7 eyes (19%), and overestimated in 13 eyes (39%). There was no significant difference in predictability between group 1 and control group (P=0.82, chi-square test). But, there was significant difference between group 2 and control group (P=0.03, chi-square test), and LI tended to overestimate potential vision in patients with complicated cataracts (P=0.01, chi-square test).

Hand-held Laser Interferometric Prediction of Postoperative Visual Acuity in Cataractous Eye

The visual acuity measured preoperatively by hand-held laser interferometer was compared to the visual acuity measured postoperatively by Han s visual acuity in 86 cataractous eyes treated by phacoemulsification with posterior chamber IOL insertion in order to get the prediction of postoperatively corrected visual acuity. The follow up period was at least 4 weeks. In the 56 cases with immature cataract and normal retina, the postoperative visual acuity was predictable within 2 lines in 52 eyes (92.8%). In 20 eyes with mature cataract including nuclear sclerosis, postoperative Han's visual acuity was predictable within 2 lines in 7 eyes (35%), and one patient showed positive disparity. In 15 eyes with retinopathy, 10 eyes (66.7%) showed positive disparity and 3 eyes (20%) showed negative disparity. We concluded that the hand-held laser interferometer is a reliable method to predict the postoperative visual acuity in immature cataract with normal retina.

Prediction of Outcomes from Cataract Patients by Using Hand Held Laser Interfrometry

To evaluate the prediction of visual outcome in cataract patients, the authors compared the preoperatively measured vision using hand-held laser interferometry(HEINE LAMBDA 100, GERMANY) and Han's visual acuity chart with the postoperatively corrected vision. Among 40 patients, in the 12 cases with immature cataract and normal macula, the postoperative measured acuity was predicted within two lines in 7 cases(58%), and in the 27 cases with mature cataract including nuclear sclerosis, the disparity under -2 was only 6 cases(21%). In the 6 cases with macular abnormality, one patient showed positive disparity. These results indicate that the prediction of visual outcome for catarct sugery using the hand-held laser interferometer was reliable in immature catarct with normal macula.

Mechanism of backward propagation of sound in the cochlea / 西安交通大学学报(医学版)

Cochlea is the auditory sensory organ in the inner ear.It normally transfers sound-induced vibrations of the cochlear partition to bioelectrical signals,which are transmitted to the brain by the auditory nerve.Sensitive cochleae can also generate sounds,named as otoacoustic emissions,which can be measured in the external ear canal.Although otoacoustic emissions have been used to evaluate hearing and to study cochlear mechanism,how emissions exit the cochlea remains unclear.Recent experimental results have showed that the backward delay of emissions is equal to or shorter than the forward delay,indicating that otoacoustic emissions exit the cochlea likely via cochlea fluids as compression waves rather than along the cochlear partition as backward traveling waves.