Volume 39 ·  Issue 05 ·  2003

To identify the quantity, constitution, distribution, human resources, medical service, equipment utilization conditions of our ophthalmic organizations.

Adopt the ophthalmology status survey forms developed by the Department of Health Administration of Ministry of Health and Office of National Committee for Prevention of Blindness to investigate the registered medical treatment organizations in the whole mainland of China in 1996. The collected data were analyzed using SAS software.

There were 4151 ophthalmological organizations, 43204 beds for ophthalmic patients, 22577 eye doctors, and 16448 ophthalmic nurses in China in 1996. 41.55% of eye doctors worked in the general hospitals above the county level.

The distribution of ophthalmic organizations and human resource is uneven. It may be the main cause to restrict the activities for prevention of blindness in China.

To investigate how the urban tertiary hospital and medical research unit cooperate with rural basic medical unit in creating the model zone in prevention of blindness.

Peking Union Medical College Hospital (PUMCH) and Shunyi District Bureau of Public Health exerted their advantages to persist and popularize the program for prevention of blindness. A collaborative program in prevention of blindness was conducted by PUMCH and Shunyi District Bureau of Public Health. The targeted subjects were the population in Shunyi District of Beijing. An epidemiological survey of eye diseases was performed in 1984. A program for prevention of blindness was established and conducted afterward.

The status of blindness in Shunyi District was unveiled by the eye epidemiological survey of eye diseases in 1984. Three-level primary eye care network and referring and treatment system for cataract blindness was established since 1987. The survey showed that the priority in prevent of blindness is surgical treatment of cataract in the area. The evaluation of the program in prevention and treatment for blindness in 1996 showed that the prevalence of blindness was decreased even it is increasing in both the total population and aged people.

The cooperation in urban tertiary hospital, medical research unit and basic health care unit, and combination in research and medical practice in prevention of blindness can promote development in the prevention of blindness and possible reverse the tendecy of blindness increase.

To evaluate the management for donated funds in cooperative projects for prevention of blindness.

Retrospectively analyze the integrative management with no blind spot in the cooperative projects conducted by the Center of Preventing and Treating Blindness in Anhui Province and the International Organization for Prevention of Blindness from 1992 to 2001.

The integrative management such as standardization of fund budget, establishment of inner-controlling system, improvement of inner-management and enhancement of project audit, returning information to donors and obtaining consent were applied in the cooperative projects for prevention of blindness. Therefore, the funds were used reasonably and projects were smoothly accomplished.

The integrative management with no blind spot is effective for the management of donated funds in the cooperative projects for blindness.

To investigate the cause of delayed diagnosis and treatment in severe fungal keratitis.

Retrospective analysis of the treatment history was performed in patients with severe fungal keratitis which attended to our hospital during 2000 to 2001. The main parameters evaluated were nature of access with the health care services, examinations undertaken, initiated treatment, and the time interval between presentation to each medical contact and to our center. Finally, the management undertaken at our center was evaluated.

69 patients (eyes) were enrolled into this investigation, of which 86% (59/69) was local residents in Shandong province, 93% (64/69) was farmer. Penetrating keratoplasty (PKP) were performed for 63 cases with a transplantation of donor cornea >8.0 mm. However, 6 eyes were enucleated because of the severe endophthalmitis. Most of patients sought medical care following a same procedure: village and towns medical service, county hospital, city medical center. The time interval between the first medical contact and presentation to our center was 22.9 days on average. 78% (54/69) patients attended to county hospitals, only 24% (13/54) patients got correct diagnosis of fungal keratitis. Smear examination had been undertaken only in 22% (12/54) of cases, the positive rate was 50%. In 30 patients who initially contact to city medical centers, 63% (19/30) was diagnosed as fungal keratitis, 73% (22/30) was given smear examination with positive result of 73% (16/22). The positive rate of corneal scraping for fungus was 93% (64/69). 46% (35/69) patients were prescribed antifungal agents of fluoconazole.

Several factors, including ignoring traumatic history and basic examination techniques, lacking of effective ophthalmic antifungal angents, cornea donor, without qualified ophthalmologists, lead to inappropriate management in fungal keratitis.

To evaluate the reliability of digital photography with retroillumination for lens as a tool to assess the degree of lens opacity, and to study the morphological features of some lens diseases using the digital images.

The cataract screener (Neitz CT-S) was connected to a computer capable of acquiring digital images of lens. The digital lens retroillumination and slit lamp images were collected in 64 eyes. Three independent separate examiners took three sets of different CT-S digital photographs in four cataract subjects. The area of lens opacification in the images was measured and analyzed using threshold adjustment in PhotoShop software and a customized program in Matlab software.

The distinct digital images of lens cortical opacity, posterior subcapsular opacity and other lens diseases were obtained with CT-S computer digital photography, which images were much better than slit lamp sectional digital images. The sensitivity and specificity of measuring lens opacification with CT-S digital images were 90% and 94% respectively. However, the digital lens retroillumination images were not as sensitive as the slit lamp images for nuclear cataracts. The variation coefficients of lens opacity area in the three sets of CT-S digital images in the same subject, which were taken by the independent examiners, were from 2.23% to 10.86%. The cortical opacification in CT-S digital images was linear, cuniform or clustered aggregate shadow configuration. The posterior subcapsular opacification was discal vacuolar or granular appearance.

The reproducibility of the CT-S digital images taken by the independent examiners is excellent. This technique can objectively show cortical or posterior subcapsular opacities, but nuclear cataracts.

To observe the changes in the lens capsule after phacoemulsification and its effects on the position of intraocular lens (IOL) and to demonstrate the best position of IOL in relation to the anterior capsule.

The present series comprised 141 eyes in 127 patients underwent phacoemulsification and foldable lens implantation with 5 mm continuous curvilinear capsulorhexis. The changes in the lens capsule and the position of IOL with dilated pupil were observed using slit lamp microscope 3 months after the operation.

Capsular bag shrinkage and white Soemmering ring along the margin of capsulorhexis were observed in all cases. Three different kinds of relationship between anterior capsule opening and the IOL optic surface were found, including the non-capture (68 eyes), partial-capture (52 eyes) and total-capture (21 eyes) relationships. The incidence of central posterior capsule opacification (PCO) was significantly higher in the total-capture group (47.6%) than that in the non-capture (11.7%) and partial-capture (21.2%) groups (P<0.01). IOL in well centered position was significantly higher in the non-capture (91.2%) and total-capture (81.0%) groups than that in the partial-capture group (42.3%) (P<0.01).

In the present study, various changes in the lens capsule were observed after phacoemulsification and foldable lens implantation. It is suggested that keeping the IOL in a non-capture position is a key point to avoid the occurrence of PCO and IOL decentration.

To study the recovery of binocular vision and the risk factors that affect the recovery in the early post-operative stage of senile cataract patients.

Patients undergone extracapsular cataract extraction with intraocular lens implantation (ECCE group) or cataract phacoemulsification with intraocular lens implantation (PHACO group) were examined for their corrected visual acuity, refractive power, simultaneous perception, fusion, near and far-distance stereoacuity.

Before operation, the visual acuity was worse in the ECCE group than that in the PHACO group (χ² =9.769, P<0.05); After operation, the visual acuity between ECCE group and PHACO group was not statistically significant (χ²=0.52 for operated eyes, P>0.05, χ²=3.52 for non-operated eyes, P>0.05). The cylinder anisometropia in ECCE group was worse than the PHACO group(χ²=12.496, P<0.01). All patients obtained simultaneous perception and fusion sense. There was more or less far-distance stereoacuity 83.3% in ECCE group and 94.7% in PHACO group, which was no statistical significant (χ²=1.456, P >0.05). Foveal near stereoacuity was established in ECCE group (2.8%) and in PHACO group (21.1%), which were statistically significant(χ²=5.029, P<0.05).

There is incomplete recovery of binocular vision in the early post-operative stage of senile cataract patients. The vision depression; especially monocular depression before surgery and the anisometropia after operation may affect the recovery of binocular vision.

To compare the accuracy of two IOL power formulas (SRK-T and SRK-II) in order to improve the accuracy of predicative IOL powers for patients with cataract and high myopia.

(1) Patient's axial lengths of the eye, K-readings and A-constants were input to the SRK-T and SRK-II formulas. The differences in predicative refraction between the two formulas were compared. (2) Eight six patients (130 eyes) with cataract and high myopia underwent phacoemulsification and posterior chamber IOL implantation were studied. These patients were randomly divided into two groups and received IOL whose power was determined by either SRK-T or SRK-II. Three months after IOL implantation, the postoperative refractions were recorded and compared with predictive refractions. Patients were followed-up for 3 to 24 months.

(1) When K-reading was 43.00 D, there was no statistically significant difference between the results from these two formulas (P>0.05) and there was no correlation between the difference and the axial lengths (P>0.05). In eyes with K-reading at 39.00 D, 41.00 D, 45.00 D, or 47.00 D, there was statistically significant difference between the results from these two formulas (P <0.05). The difference between the two formulas was in proportional to the axial length (P<0.05). (2) The mean error between the postoperative refraction and predictive refraction determined by SRK-T and SRK-II formula was 0.08 D and -0.79 D, respectively. The difference between these two formulas was statistically significant (P<0.05).

Selection of IOL power formula should consider the axial length, K-reading and other related factors. SRK-T formula is appropriate for high myopia eyes with axial length longer than 26.0 mm. In this group, SRK-T formula is much more accurate than the SRK-II formula.

The purpose of this study is to determine the influence of two different diameter of posterior capsulotomy on visual field.

Forty patients with posterior capsule opacification (PCO) of grade II after phacoemulsification and intraocular lens implantation were randomly divided into two groups. 20 cases received laser capsulotomy with 2 mm diameter. Other 20 cases received laser capsulotomy with 4 mm diameter. One and half months after laser capsulotomy, vision field of every patient was examined using the automated perimetry for central 30° and peripheral 60°. Visual field in 21 patients with a transparent posterior capsule after cataract surgery was also evaluated by the same automated perimetry.

There were significant reductions in the total visual field sensitivity, the mean deviation (MD) and the pattern standard deviation (PSD) in 2 mm diameter capsulotomy group compared with 4 mm diameter capsulotomy group (P<0.001). There were no significant difference in visual field between 4 mm capsulotomy group and the transparent posterior capsule group (P>0.05).

Better visual acuity could be obtained after laser capsultotomy with 2 mm capsulotomy, however the generalized sensitivity reduction and irregular localized depression of visual island might occurred. 4 mm diameter capsulotomy may be a better choice in laser capsulotomy in patients with PCO.

To evaluate the feasibility of krypton laser-induced choroidal neovascularization (CNV) model in the Brown Norway rats in order to establish the foundation for studying the mechanism of CNV and for the development of treatment for CNV.

Experimental eyes in 33 rats were received a series of 10 krypton red laser (647 nm) lesions per eye (360 mW, 50 μm, 0.05 s). Fundus fluorescein angiography (FFA) and indocyanine green angiography (ICGA) were performed, then the rats were sacrificed immediately, the eyes were enucleated and processed for histopathologic examination and transmission electron microscopy on days 3, 7, 14, 21, 28 and 56.

CNV was firstly appeared on day 7 after photocoagulation, reaching the peak on day 21. The incidence of CNV was 76.0%. Disciform leakage staining appeared in the FFA. ICGA showed that the disciform area was filled with CNV. CNV was ascertained by light microscopy and electron microscopy. The thickness of laser-induced CNV was increased from day 7 to day 21 (P<0.01) and no significant progress occurred after day 21 (P>0.05).

The present studies demonstrated that krypton laser photocoagulation could be used to produce choroidal neovascularization experimental model in the Brown Norway rat. CNV can be induced rapidly by the method, persists for a long period and at a high successful rate.