[Clinical effects of two different hydroxyapatite bone graft materials during maxillary sinus lifting surgery with bone grafting and simultaneous implantation of implants].

PURPOSE: To compare the clinical effects of two different hydroxyapatite bone graft materials in maxillary sinus lifting surgery with bone grafting and implantation at the same time. METHODS: Seventy-two patients with implantation in the maxillary posterior dental area and insufficient bone mass admitted to the First Affiliated Hospital of Bengbu Medical College were collected from March 2018 to April 2019, and they were divided into experimental group(n=36) and control group(n=36) by random number table. Patients in the control group used hydroxyapatite composite material, while patients in the experimental group used nano-hydroxyapatite composite material. The clinical effects, bone increment and bone density changes of the two groups of implants were compared, and postoperative implant stability and complications of the two groups were compared. Statistical analysis was performed with SPSS 18.0 software package. RESULTS: The survival rate of implants in the experimental group was significantly higher than that in the control group at 24 months (P＜0.05). Alveolar bone resorption in the experimental group was significantly lower than the control group 6 months after surgery(P＜0.05). The bone mineral density of implants in the experimental group was significantly higher than the control group 6 months and 12 months after operation(P＜0.05). The implant stability coefficient value of the experimental group was significantly higher than the control group 12 months after operation(P＜0.05). There was no significant difference in the total complication rate between the two groups(P＞0.05). CONCLUSIONS: In maxillary sinus lift, the survival rate of nano-hydroxyapatite composite material implanted in the same period is high, which can improve postoperative bone metabolism and increase implant stability with good safety.

[Correlation between quantitative nerve fiber layer thickness and mean defect of visual field in primary open angle glaucoma].

OBJECTIVE: To establish whether the structural parameters provided by GDx can be used to reflect functional damage in the mean defect of visual field. METHODS: 97 (191 eyes) patients with primary open angle glaucoma underwent examination with GDx and Octopus 1-2-3 automatic perimeter. The relationship between the retinal nerve fiber layer parameters and mean defect of visual field was analysed by ANOVA, Pearson's correlation(r), scatter plot and linear regression. RESULTS: The parameters of GDx decreased with increasing mean defect of visual field, measured both globally and regionally; r: SA = -0.58, TSNIT = -0.52, IA = -0.52, NFI = -0.48 and IES = -0.33. All parameters were negative correlation with mean defect of visual field and there was significant correlation among these parameters, except IES (P < 0.05). The superior mean defect of visual field increased with decreasing inferior RNFL (r = -0.61), inferior visual field mean defect increased with decreasing superior RNFL (r = -0.59). There were significant correlation among these parameters. CONCLUSION: Quantitative measures of the retinal nerve fiber layer using GDx were correlated with mean defect of visual field in patients with glaucoma. GDx can be used for follow up.

Frequency-doubling threshold perimetry in predicting glaucoma in a population-based study: The Beijing Eye Study.

OBJECTIVE: To determine the predictive value of frequency-doubling threshold perimetry for glaucoma in a population-based study. METHODS: The Beijing Eye Study, a population-based study on subjects 40 years or older, included an ophthalmic examination with fundus photography and frequency-doubling threshold perimetry. Glaucoma was defined by a glaucomatous optic disc appearance. RESULTS: The study population consisted of 4349 subjects (8615 eyes). Among 207 glaucomatous eyes (2.4%), 74 (35.7%) did not show any abnormality on frequency-doubling threshold perimetry, suggesting a diagnostic sensitivity of 64.3%. In the total study population, a visual field defect was found in 905 eyes (10.5%). In 133 (14.7%) of these eyes, a glaucomatous appearance of the optic disc was detected, and 772 eyes (85.3%) had a nonglaucomatous optic disc appearance (either normal or with nonglaucomatous optic nerve damage, retinal disease, corneal disease, or cataract). For 450 eyes (49.7%) with a visual field defect, the cause of the perimetric defect was not detected. CONCLUSIONS: In a population-based study, frequency-doubling threshold perimetry has a sensitivity of about 64% to detect glaucoma. If the result is abnormal, the probability of glaucoma is about 15%. When results of frequency-doubling threshold perimetry are abnormal, the cause of the visual field defect may not be detectable in 50% of subjects.

[Single channel multifocal VEP studies in normal Chinese].

OBJECTIVE: To investigate the waveform characters of single channel mVEP and its variability in normal Chinese people. METHODS: VERIS Science 4.3 system was used to record and analyze single channel mVEP. The stimulation was performed with a 60 pattern segment dartboard configuration. The Michelson contrast was 99% and the repetition rate 75 Hz. Recording electrodes were placed 3 cm above and 3 cm below the inion. The m-14 sequence required 4 minutes of recording time per eye, which was divided into 8 short segments. The signal was amplified 100 000 times and band-pass filtered between 3 and 100 Hz. The first slices of second kernel at 60 locations were analyzed. The main wave peak-to-trough amplitude and latency from 30 to 130 ms signal window were measured and calculated with the costumed Matlab program. The study included 64 normal subjects (39 women and 25 men). The age range was 13 - 66 years. 7 subjects were tested 2 - 7 times on different occasions for reproducibility. The statistic analysis was performed with Excel and SPSS. RESULTS: In mVEP trace array, the polarity of upper hemifield traces was usually opposite to lower hemifield traces. However, at near vertical meridian areas and near below horizontal meridian areas, the trace polarity had some variability. The main wave mean amplitudes of 60 location responses in left eye were from 0.177 microV to 0.401 microV. The amplitude CVs for 60 locations were from 36.6% to 60.7%. The mean latencies of 60 location responses were from 100 to 116 ms, and latency CVs were from 8.8% to 18.1%. The smaller signals located in zones of upper periphery, along vertical meridian, below horizontal meridian and the larger signals located in near horizontal meridian areas and near non-axial meridian areas which distribution is like a bow tie. There was smaller amplitude variability in the some upper hemifiled locations with smaller amplitude, and there was larger amplitude variability in the some lower hemifiled locations with larger amplitude. The mean amplitudes of all 60 locations in male subjects were lower than that in female subjects, in which 30 locations were low significantly (P < 0.05). The gender influence on latency was less, in which only at 10 locations the difference was significant (P < 0.05). At 20 locations of all, which were mainly distributed at near vertical meridian of lower hemifiled, there was a significant positive correlation of age with amplitude. The age influence on latency was also less. CONCLUSIONS: The larger variability of main wave peak-to-trough amplitude in single channel mVEP existed in different subjects and different locations of same subject. In analysis of mVEP amplitude, the influence of VEP curve location, gender and age should be considered. The main wave latencies of intersubject and intrasubject have smaller variability, and less effect by gender and age, so latency may be a useful diagnostic parameter.

[The value of frequency doubling perimetry in glaucoma screening of aged 40 or more population].

OBJECTIVE: To investigate the diagnosis value of the frequency doubling perimetry (FDP) screening program in the aged 40 or more natural population-based glaucoma screening. METHODS: In 3 natural villages of Daxing District and 4 northern metropolitan communities of Beijing, 4439 subjects aged 40 or over were screened for glaucoma from May to October in 2001. The screening protocol C-20-1 of the frequency doubling perimetry (FDP) was used in all subjects. For suspect glaucoma subjects, TOP threshold visual field testing with an Octopus perimeter, gonioscopy and stereo fundusgraphy were performed on different days. Detected Glaucoma patients were classified as mild (MD 5 dB or less), moderate (MD > 5 dB and < 10 dB) and advanced (MD 10 dB or more) degrees according to their Octopus test results. FDP parameters including test time, numbers of abnormal location, comtotalon score and score by quadrant were analyzed. Data from one eye of normal subjects and milder eye of optic nerve damage in glaucoma subjects were analyzed. RESULTS: After excluding subjects whose fixation error or false positive error was > 0.33, data from 4330 subjects (97.54%) were analyzed. If abnormality of one location or more was used as a FDP cutoff, and subjects were divided into normal and glaucoma two groups (excluded other eye diseases in non-glaucoma subjects); the FDP had a sensitivity of 50.70% (72/142), a specificity of 90.58% (2260/2340), an area under the ROC curve (AUC) of 0.74, a positive predictive value (PV) of 47.71%, a negative predictive value of 96.95%, a positive likelihood ratio (LR) of 14.83 and a negative LR of 0.51. If excluded the eyes without glaucomatous optic nerve changes and visual field damage, the FDP had a sensitivity of 76.39%, an AUC of 0.87, a positive PV of 40.74%, a negative PV of 99.25%, a positive LR of 22.34 and a negative LR of 0.24. The sensitivity of detecting mild, moderate and advanced glaucoma was 54.17%, 76.00% and 100.00%, respectively. There was strong negative correlation between FDP quadrant score and quadrant mean sensitivity (MS) of Octopus perimetry in glaucoma patients (Spearman correlation, Rs = -0.732, -0.628, -0.639, -0.679, all P = 0.000). CONCLUSIONS: The FDP screening protocol C-20-1 is a very rapid functional test for screening glaucoma in large natural populations aged 40 or more and is proven to be feasible. It has high specificity and good sensitivity for moderate and advanced glaucoma.

[The prevalence and its screening methods of primary open angle glaucoma in defined population-based study of rural and urban in Beijing].

OBJECTIVE: The purpose of the study is to determine the prevalence of primary open-angle glaucoma (POAG) in persons aged 40 or above in Beijing, China. METHODS: From June 2001 to October 2001, the screening population was identified by a door-to-door census in five metropolitan resident areas in the north of Beijing and three villages in a county south to Beijing. The screening included visual acuity, frequency doubling perimetry (FDP, C-20 screening program), non-contact tonometry, slit lamp microscopy, anterior chamber depth (Van Herick method), and fundus photography. The suspect glaucoma and definite glaucoma patients were asked to have an examination of Octopus 1-2-3 perimetry (G1X TOP threshold program), repeat tonometry, gonioscopy and fundus stereo-photography at Beijing Tongren Hospital. RESULTS: There were 4451 subjects who were examined at the study sites. The response rates in rural and urban were 79.58% and 87.13%, respectively. In this 40 years-old or above population, the prevalences of POAG were 1.97% in rural men, 2.07% in urban men, 1.04% in rural women and 1.42% in urban women. In this study, 92.30% POAG patients in rural and 87.30% POAG patients in urban were new diagnosed cases. The prevalence of POAG increased with age and the change was exponential. In 50% POAG patients first IOP measurement was less than 21 mm Hg (1 mm Hg = 0.133 kPa). The prevalence of monocular eye blindness was 15.40% and 10.90% in rural and urban, respectively. CONCLUSIONS: Owing to use fundus photography and integrated evaluation of optic disc, it is possible to diagnose in earlier stage of POAG. This study identifies more patients with POAG than any previous population-based studies of China, and is similar to other studies of Asia such as in India and Singapore. The reason of lower POAG prevalence in rural women than in urban may be that the anterior chamber depth of rural women is shallower than that of urban women. It may cause difficult to differentiate the chronic primary angle closure glaucoma from POAG at screening sites, so the part POAG patients may be included in primary angle closure glaucoma patients.

[Prevalence of low vision and blindness in defined populations in rural and urban areas in Beijing].

OBJECTIVE: To investigate the prevalence and causes of low vision and blindness in Beijing residents aged 40 and over. METHODS: 4,451 residents aged 40 and over in 3 rural communities and 5 urban communities in Beijing underwent eye examination, including examination of distant and near visual acuity (VA), best corrected distant and near VA, pinhole VA, and visual field, slit lamp biomicroscopy, and dilated ocular examination in the form of in-home survey by defined population-based sampling. The medical history was surveyed too. The data were analyzed based on the criteria of the World Health Organization. RESULTS: The general prevalence rates of low vision and blindness were 0.99% (95% CI: 0.70-1.28) and 0.39% (95% CI: 0.21-0.57) respectively. The prevalence rate of low vision in females was 1.45%, 2.23 times that of males (0.65%) (OR: 1.97, 95% CI: 1.00-3.95). The prevalence rate of low vision of rural residents was 1.76%, 2.89 times that of urban residents (0.61%) (OR: 2.93, 95% CI: 1.43-6.11). The prevalence rate of blindness in females was 0.64% and 0.37% in males. The prevalence rate of blindness of rural residents was 1.06%, 2.04 times that of the urban residents (0.52%) (OR: 3.77, 95% CI: 1.41-10.62). The 3 major causes of blindness were cataract (37.50%), glaucoma (29.20%), and high myopic macular degeneration (8.30%). The prevalence of blindness increased with age. CONCLUSION: The prevalence rates of low vision and blindness are higher in the rural areas. Cataract, glaucoma, and high myopic macular degeneration are the major causes of blindness. The prevalence of low vision and blindness are influenced by age, sex; area, health care level, educational level, and environmental factors.