Pterostilbene could alleviate diabetic cognitive impairment by suppressing TLR4/NF-кB pathway through microbiota-gut-brain axis.

Diabetic cognitive impairment (DCI) is a serious neurodegenerative disorder caused by diabetes, with chronic inflammation being a crucial factor in its pathogenesis. Pterostilbene is a well-known natural stilbene derivative that has excellent anti-inflammatory activity, suggesting its potential medicinal advantages for treating DCI. Therefore, this study is to explore the beneficial effects of pterostilbene for improving cognitive dysfunction in DCI mice. A diabetic model was induced by a high-fat diet plus streptozotocin (40 mg·kg-1 ) for consecutive 5 days. After the animals were confirmed to be in a diabetic state, they were treated with pterostilbene (20 or 60 mg·kg-1 , i.g.) for 10 weeks. Pharmacological evaluation showed pterostilbene could ameliorate cognitive dysfunction, regulate glycolipid metabolism disorders, improve neuronal damage, and reduce the accumulation of ß-amyloid in DCI mice. Pterostilbene alleviated neuroinflammation by suppressing oxidative stress and carbonyl stress damage, astrocyte and microglia activation, and dopaminergic neuronal loss. Further investigations showed that pterostilbene reduced the level of lipopolysaccharide, modulated colon and brain TLR4/NF-κB signaling pathways, and decreased the release of inflammatory factors, which in turn inhibited intestinal inflammation and neuroinflammation. Furthermore, pterostilbene could also improve the homeostasis of intestinal microbiota, increase the levels of short-chain fatty acids and their receptors, and suppress the loss of intestinal tight junction proteins. In addition, the results of plasma non-targeted metabolomics revealed that pterostilbene could modulate differential metabolites and metabolic pathways associated with inflammation, thereby suppressing systemic inflammation in DCI mice. Collectively, our study found for the first time that pterostilbene could alleviate diabetic cognitive dysfunction by inhibiting the TLR4/NF-κB pathway through the microbiota-gut-brain axis, which may be one of the potential mechanisms for its neuroprotective effects.

Combination of UHPLC-Q Exactive-Orbitrap MS, Bioinformatics and Molecular Docking to Reveal the Mechanism of Huan-Lian-Jie-Du Decoction in the Treatment of Diabetic Encephalopathy.

Diabetic encephalopathy (DE) is a serious complication of diabetes, which affects patients' quality of life. We aimed to explore HLJDD in the treatment of DE by LC/MS and bioinformatics. UPLC-Q Exactive-Orbitrap MS was employed to clarify the compounds. The modules and hub targets of DE were gained from WGCNA. Subsequently, an Herb-Compound-Target network was constructed and enrichment analysis was used. In addition, a protein-protein interaction (PPI) network was constructed and molecular docking was used to verify the above analysis. As result, 138 compounds and 10 prototypes in brain were identified. In network pharmacology, 8 modules and 5692 hub targets were obtained from WGCNA. An Herb-Compound-Target network was constructed by 4 herbs, 10 compounds and 56 targets. The enrichment analysis showed that the treatment of DE with HLJDD involve oxidative stress and neuroprotection. Beside, SRC, JUN, STAT3, MAPK1 and PIK3R1 were identified and as hub targets of HLJDD in treating DE. Moreover, Molecular docking showed that five hub targets had strong affinity with the corresponding alkaloids. Therefore, we explored the underlying mechanisms of HLJDD in the treatment of DE and to provide the theoretical and scientific basis for subsequent experimental studies and clinical applications.

Protective effects of Huang-Qi-Ge-Gen decoction against diabetic liver injury through regulating PI3K/AKT/Nrf2 pathway and metabolic profiling.

ETHNOPHARMACOLOGICAL RELEVANCE: Huang-Qi-Ge-Gen decoction (HGD) is a traditional Chinese medicine prescription that has been used for centuries to treat "Xiaoke" (the name of diabetes mellitus in ancient China). However, the ameliorating effects of HGD on diabetic liver injury (DLI) and its mechanisms are not yet fully understood. AIM OF THE STUDY: To elucidate the ameliorative effect of HGD on DLI and explore its material basis and potential hepatoprotective mechanism. MATERIALS AND METHODS: A diabetic mice model was induced by feeding a high-fat diet and injecting intraperitoneally with streptozotocin (40 mg kg-1) for five days. After the animals were in confirmed diabetic condition, they were given HGD (3 or 12 g kg-1, i. g.) for 14 weeks. The effectiveness of HGD in treating DLI mice was evaluated by monitoring blood glucose and blood lipid levels, liver function, and pathological conditions. Furthermore, UPLC-MS/MS was used to identify the chemical component profile in HGD and absorption components in HGD-treated plasma. Network pharmacology and molecular docking were performed to predict the potential pathway of HGD intervention in DLI. Then, the results of network pharmacology were validated by examining biochemical parameters and using western blotting. Lastly, urine metabolites were analyzed by metabolomics strategy to explore the effect of HGD on the metabolic profile of DLI mice. RESULTS: HGD exerted therapeutic potential against the disorders of glucose metabolism and lipid metabolism, liver dysfunction, liver steatosis, and fibrosis in a DLI model mice induced by HFD/STZ. A total of 108 chemical components in HGD and 18 absorption components in HGD-treated plasma were preliminarily identified. Network pharmacology and molecular docking results of the absorbed components in plasma indicated PI3K/AKT as a potential pathway for HGD to intervene in DLI mice. Further experiments verified that HGD markedly reduced liver oxidative stress in DLI mice by modulating the PI3K/AKT/Nrf2 signaling pathway. Moreover, 19 differential metabolites between normal and DLI mice were detected in urine, and seven metabolites could be significantly modulated back by HGD. CONCLUSIONS: HGD could ameliorate diabetic liver injury by modulating the PI3K/AKT/Nrf2 signaling pathway and urinary metabolic profile.

[Research progresses in treating infectious keratitis with photodynamic therapy].

Photodynamic therapy(PDT) as a new therapeutic method is increasing widely used in ocular surface disease. Along with intensive studies of microorganism inhibition and promoting function in tissue repairing of PDT have been developed, PDT been gradually applied to treating infectious keratitis in clinical. We review mechanism, sterilization and application in infectious keratitis of PDT.

[Role of in vivo confocal microscopy in the management of infectious keratitis].

Infectious keratitis remains a severe ocular condition that can lead to irreversible complications and even blindness. An early diagnosis of an infective microorganism leading to effective treatment may improve the outcome of infectious keratitis.However, the accurate and rapid identification of the infectious agent remains a challenge for the ophthalmologist.In vivo confocal microscopy (IVCM) is a noninvasive imaging technique that provides high-resolution images of ocular surface structures at a cellular level and infectious keratitis represents one of its most important clinical uses. The value of IVCM has been demonstrated in the diagnosis of acanthamoeba and filamentous fungal keratitis. The follow-up of such corneal infections may also be improved by this noninvasive imaging technique.However, the current resolution of IVCM limits its use in cases of bacterial and viral keratitis.

Beijing Eye Public Health Care Project.

PURPOSE: The Beijing Eye Public Health Care Project was designed to screen all elderly subjects (age 55-85 years) of the rural region of Greater Beijing. It was developed as a preparatory step for a telemedicine-based public health care system in ophthalmology in China. DESIGN: Population-based public health care project. PARTICIPANTS: Elderly subjects (age 55-85 years) of the rural region of Greater Beijing. METHODS: Project participants were visited, interviewed, and examined by 2500 high school graduates trained as ophthalmic technicians. If visual acuity was <0.30, subjects were referred to primary health care centers where ocular photographs were taken. Using telemedicine, the photographs were transmitted to a reading center and causes for visual impairment were diagnosed. MAIN OUTCOME MEASURES: Practicability of a mass screening system in ophthalmology; prevalence of visual impairment and causes for it. RESULTS: Out of 692 323 eligible inhabitants, 562 788 (81.3%) subjects participated. Visual impairment in ≥1 eye was detected in 54 155 (9.62%) subjects, and among them, 30 164 (5.36%) subjects had bilateral visual impairment. Ocular fundus photographs were taken for 37 281 subjects. Cause for visual impairment was cataract in 19 163 (3.41%) of all screened subjects, glaucoma in 1606 (0.29%) subjects, diabetic retinopathy in 905 (0.16%) subjects, other macular diseases in 2700 (0.48%) subjects, pterygium in 1381 (0.25%) subjects, and corneal leukoma in 283 (0.05%) subjects. For 5853 (1.04%) subjects, a diagnosis of premature or mature cataract was made showing the urgent need of cataract surgery. After cataract surgery, visual acuity was ≥0.30 in 1464 (91.7%) of 1596 postoperatively reexamined subjects. CONCLUSIONS: Using a telemedicine approach, the Beijing Eye Public Health Care Project developed, applied and tested an infrastructure for ophthalmic mass screening of >500 000 elderly inhabitants with a response rate of >80%. Beside cataract, retinal diseases including diabetic retinopathy and glaucoma were major causes for visual impairment. FINANCIAL DISCLOSURE(S): The authors have no proprietary or commercial interest in any of the materials discussed in this article.

Effects of soy isoflavone supplementation on patients with diabetic nephropathy: a systematic review and meta-analysis of randomized controlled trials.

Diabetic nephropathy (DN) is a microvascular complication that is becoming a worldwide public health concern. The aim of this study was to assess the effects of dietary soy isoflavone intervention on renal function and metabolic syndrome markers in DN patients. Seven databases including Medline, the Cochrane Central Register of Controlled Trials, Science Direct, Web of Science, Embase, China National Knowledge Infrastructure, and WanFang were searched for controlled trials that assessed the effects of soy isoflavone treatment in DN patients. Finally, a total of 141 patients from 7 randomized controlled trials were included. The meta-analysis showed that dietary soy isoflavones significantly decreased 24-hour urine protein, C-reactive protein (CRP), blood urea nitrogen (BUN), total cholesterol (TC), triglycerides (TG), low-density lipoprotein cholesterol (LDL-C), and fasting blood glucose (FBG) in DN patients. The standard mean difference was -2.58 (95% CI: -3.94, -1.22; P = 0.0002) for 24-hour urine protein, -0.67 (95% CI: -0.94, -0.41; P < 0.00001) for BUN, -6.16 (95% CI: -9.02, -3.31; P < 0.0001) for CRP, -0.58 (95% CI: -0.83, -0.33; P < 0.00001) for TC, -0.41 (95% CI: -0.66, -0.16; P < 0.00001) for TG, -0.68 (95% CI: -0.94, -0.42; P < 0.00001) for LDL-C, and -0.39 (95% CI: -0.68, -0.10; P = 0.008) for FBG. Therefore, soy isoflavones may ameliorate DN by significantly decreasing 24-hour urine protein, BUN, CRP, TC, TG, LDL-C, and FBG.

Progress in the basic and clinical research on the Schlemm's canal.

Glaucoma is a leading cause of irreversible blindness in the world. Intraocular pressure (IOP) plays a key role in glaucoma development and progression. Schlemm's canal (SC), an important structure of the anterior chamber angle, regulates the flow of aqueous humor and maintains IOP. Because of its special function of aqueous outflow, the SC has been intensive investigated recently. Several characteristics of SC in anatomy, physiology and pathophysiology have been revealed. Compare to normal, glaucomatous SC cells are more sensitive to substrate stiffness, have higher stiffness and and lower porosity leading to higher outflow resistance. And SC collapse caused by acute IOP increase is partially or totally reversal. With advanced inspection techniques, high-quality images of the SC can be obtained in vivo, which facilitates SC quantitative measurements clinically and allows us to investigate a new therapy paradigm for glaucoma. In this review, we summarize the basic and clinical research that focused on mechanisms of aqueous outflow resistance and SC changes in physiological, pathological, and post-treatment states.

[Operation of cornea grafting micro-surgery robot system].

OBJECTIVE: To design the robotic mechanism of the cornea grafting micro-surgery system and evaluate its experimental feasibility and efficacy. METHODS: It was an experimental study. Based on computer assisted cornea grafting surgery (CACGS), the prototype about cornea grafting robot, which consists of six subsystems, was developed. The system was used for looping incision and suturing for 20 rabbit corneas. Experimental data were studied including the error of target incision position, the actual cutting depth and the cutting edge span in order to evaluate the system's clinical value. All above statistical descriptions were performed using SPSS software version 11.5. RESULTS: 20 corneas were looping incised and sutured by the robot-assisted cornea grafting micro-surgery system successfully. The error of target incision position was (0.356 + or - 0.040) mm. With CACGS, the cutting edge span (A) was (0.855 + or - 0.040) and the actual cutting depth error was less than 10 microm. Corneal structure and thickness was showed no change and cutting edge of cornea was displayed regularity in pathological examination. To suturing system, suturing span was (2.15 + or - 0.09) mm and the error of span (0.15 + or - 0.02) mm. CONCLUSIONS: The cornea grafting micro-surgery system developed is used for cornea grafting of some animals successfully. The experiment results demonstrate the stability and efficiency of the robot.

[Mutant prevention concentrations of antibacterial agents to ocular pathogenic bacteria].

OBJECTIVE: To establish a method to measure mutant prevention concentration (MPC) in vitro, and to measure MPC of antibacterial agents for ocular bacteria caused keratitis. METHODS: It was an experimental study. Forty strains of ocular bacteria were separated from cornea in Beijing Institute of Ophthalmology, which included 8 strains of Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pneumoniae, Pseudomonas aeruginosa and Klebsiella pneumoniae respectively. The minimal inhibitory concentration (MIC) of the levofloxacin (LVF), ofloxacin (OFL), ciprofloxacin (CIP), norfloxacin (NFL), tobramycin (TOB) and chloromycetin (CHL) were determined by agar dilution method from National Committee of Clinical Laboratory Standard (NCCLS). The MPC were measured by accumulate-bacterial methods with bacterial population inoculated more than 1.2 x 10(10) colony forming units per milliliter with Mueller-Hinton broth and tryptic soy agar plate. With the software of SPSS 11.0, the datum such as the range of MIC, MPC, MIC90 and MPC90 were calculated, and the selection index (MPC90/ MI90) and mutant selection window (MSW) were obtained. RESULTS: The MI90 of LVF and TOB (4 mg/L) to Staphylococcus aureus strains were the lowest. CIP showed the lowest MIC90 (0.25 mg/L) to Pseudomonas aeruginosa among six kinds of antibacterial agents. The MIC90 of LVF to Staphylococcus epidermidis (256 mg/L), Streptococcus pneumoniae (1 mg/L) and Klebsiella pneumoniae (0.25 mg/L) were lower than other antibacterial agents. The MPC90, MSW and the MPC90/MIC90 of levofloxacin showed lower values compared with other antibacterial medicines. From all the datum, the MIC90 of CHL was the highest and the activity was the weakest. Although the activity of LVF was higher to every kind of bacteria, CIP had the highest activity antibacterial to Pseudomonas aeruginosa. The capacity of CHL and TOB was weaker than Quinolones for restricting resistant mutants on ocular bacteria. LVF had the strongest capacity for restricting resistant mutants among Quinolones. CONCLUSION: LVF has better antibacterial effects and stronger capacity for restricting the selection of resistant mutants on ocular bacteria than other antibacterial agents.

[Etiological analysis of ocular non-viral microbial isolates in children and their antibiotics susceptibility in vitro].

OBJECTIVE: To analyze the types, distribution characteristics and in vitro susceptibility of antibiotic agents of ocular non-viral microbial isolates in children. METHODS: Experimental research.785 specimens obtained from children below the age of 14 in Beijing Tongren Hospital during 1999 to 2004 were cultured and identified for bacterium, fungus and Acanthamoeba respectively at Beijing Institute of Ophthalmology. Microbial culture-positive rate, susceptibility patterns and the organisms distribution of positive cultures were retrospectively analyzed. The results were statistical analyzed by chi(2). RESULTS: Of the 785 specimens, 211 were culture positive. The percentage of positive culture was 26.88%. Of those positive cultures, 176 (83.41%) had pure bacterial infections, 32 (15.17%) had pure fungal infections, and 3 (1.42%) had pure cultures of Acanthamoeba. Of the 176 bacterial positive cultures, polymicrobial infection was present in 38 cases (33 bacterial, 5 fungal and bacterial). Of 214 bacterial isolates, the most common isolate was Neisseria gonorrhoeae (39/214, 18.22%), followed by Staphylococcus epidermidis (37/214, 17.29%), and Corynebacterium spp. (36/214, 16.82%). The most common fungal pathogen isolated was Fusarium spp. representing 25.00% (8/32) of all positive fungal cultures, followed by Aspergillus spp. (15.63%, 5/32). The sensitivity of tobramycin, norfloxacin, gentamicin, amikacin, ciprofloxacin, ofloxacin, rifampicin and levofloxacin of bacteria was 62.57%, 64.94%, 70.06%, 70.87%, 71.19%, 73.89%, 85.80% and 87.50%. Gram-positive isolates were susceptible to levofloxacin. Gram-negative isolates showed high susceptible to ciprofloxacin, ofloxacin and levofloxacin. The fungal isolates were most susceptible to natamycin, followed by terbinafine, but resistant to fluconazole. CONCLUSIONS: Bacteria are the most common pathogens in non-viral microbial eye infection in children. Neisseria gonorrhoeae, Staphylococcus epidermidis, and Corynebacterium spp. are the most common bacterial pathogens, which are highly susceptible to levofloxacin and rifampicin. Fusarium spp. and Aspergillus spp. are the most common fungal pathogens, which are highly susceptible to natamycin but resistant to fluconazole.

[Prevalence and risk factors for trachoma in primary school children in Datong City in China].

OBJECTIVE: To assess the prevalence and risk factors for trachoma among primary school children in Datong City, China. METHODS: An epidemiological survey was carried out in Datong City in 2006. Children aged 6 to 14 years old in primary school were selected by a cluster sampling in which class shift was the sampling unit. Trachoma was clinically assessed according to the simplified classification for trachoma proposed by the World Health Organization (WHO). If the child was clinically diagnosed as trachoma, a conjunctival swab would be taken for detecting C. trachomatis by antigen test and polymerase chain reaction (PCR). RESULTS: A total of 1236 children were examined and 135 cases of trachoma were found, the prevalence of trachoma was 10.9% (95% CI: 9.2% - 12.6%). Follicular trachoma was found in 86.7% of the cases and intense trachoma in 13.3%. The overall prevalence of trachoma was higher for females than for males (13.1% versus 8.8%, P = 0.016). Thirteen (9.6%) cases were positive in C. trachomatis antigen test, and 86 (63.7%) cases were positive by PCR. Poor ocular hygiene and sharing wash cloth and face basin with households were the main risk factors. CONCLUSION: Trachoma is endemic among primary school children in Datong City in China.

[Analysis on susceptibility of ocular bacterial pathogens to four kinds of fluoroquinolone].

OBJECTIVE: To assess the in vitro susceptibilities of ocular bacterial isolates to Gatifloxacin and other fluoroquinolones which are often used in ophthalmic treatment. METHODS: Non-randomized, non-comparative, retrospective study. Ocular bacterial isolates (n = 619) from Beijing Institute of Ophthalmology were tested for their susceptibilities to gatifloxacin, ciprofloxacin, ofloxacin and levofloxacin in vitro by the Kirby-Bauer disk diffusion method. RESULTS: The total number of ocular bacterial isolates was 619 from January, 2005 to December, 2006 including gram-positive cocci 372(60.1%), gram-negative cocci 7 (1.1%), gram-positive bacilli 60 (9.7%), gram-negative bacilli 177 (28.6%), other 3 (0.5%). The percentage of susceptibility in total ocular bacterial isolates to gatifloxacin, ciprofloxacin, ofloxacin and levofloxacin was 88.4%, 72.1%, 64.8% and 54.4%. The susceptibility of Staphylococcus species to gatifloxacin (89.9%) was significantly higher than ciprofloxacin (38.8%), ofloxacin (48.2%) and levofloxacin (61.6%). Streptococcus species showed significantly higher susceptibility to gatifloxacin (93.2%), levofloxacin (89.2%) and ofloxacin (87.8%) than ciprofloxacin (62.2%). The susceptibility of gram-positive bacilli to gatifloxacin (86.7%) was significantly higher than ciprofloxacin (58.3%); All above differences are significant (P < 0.0083). Gram-negative cocci, enteric bacilli family and Pseudomonas species have the equivalent susceptibility to gatifloxacin, ciprofloxacin, ofloxacin and levofloxacin (P > 0.05). CONCLUSIONS: Most of ocular bacterial are susceptible to gatifloxacin in vitro, especially gram-positive bacteria including Staphylococcus species, Streptococcus species and gram-positive bacilli.

[Experimental study of non-tuberculous mycobacterial keratitis in rabbits].

OBJECTIVE: To study clinical manifestation and pathology change of different time points of rabbit keratitis caused by non-tuberculous mycobacteria (NTM). METHODS: Forty-eight eyes from 48 rabbits were randomly divided into three groups:under-flap infection group (UFI group), under-flap infection group with corticosteroid (UFIC group) and surface infection group (SI group). The cornea infiltration area of all rabbits was observed. Bacterial quantitative culture and histopathological examination were performed. RESULTS: In the earliest stage (5 days), the cornea was cloudy and edematous. In the middle stage (7 - 14 days), cornea stromal infiltration became its major clinical sign. In the last stage (21 days), corneal neovascularization and fibrosis were developed. The mean stromal infiltration area in UFIC group was greater than those of UFI group and SI group (F = 9.362, 8.341, P < 0.05). The number of NTM in UFIC group was higher than those of UFI group and SI group (F = 411.272, P < 0.05). In histopathological examination, there were infiltrates with polymorphonuclear leukocytes (PMN) in the corneal stroma in the early stage and acid-fast bacilli was found. A plenty of lymphocytes in the cornea was found in the middle stage of NTM keratitis. In the latter stage, the fibroblast cells proliferation and corneal ulcer were cured. During the course of this infection, the number of CD4+, CD8+ T lymphocyte increased significantly, and then decreased gradually following the regress of the infection. In the stage (5 - 21 days), CD4+ T lymphocyte decreased significantly in UFIC group compared with other two groups (F = 21.907, 196.521, 12.552, 11.100, P < 0.01). CONCLUSIONS: The clinical characteristic of rabbit keratitis is the multifocal dense superficial stromal infiltrates. CD4+ T lymphocyte may play an important role in NTM keratitis.

Systematic review and Meta-analysis comparing modified cross-linking and standard cross-linking for progressive keratoconus.

AIM: To compare the effectiveness and safety between modified cross-linking (MC) and standard cross-linking (SC) in mild or moderate progressive keratoconus. METHODS: Eligible studies were retrieved from four electronic databases, including CENTRAL, Clinical Trials gov, PupMed and OVID MEDLINE. We set post-surgical maximum K value (Kmax) as the primary outcome. In addition, uncorrected and corrected distant visual acuity (UDVA and UDVA), spherical equivalent (SE), endothelial cell density (ECD), central cornea thickness (CCT) and depth of demarcation line (DDL) were Meta-analyzed as secondary outcomes. Mean differences for these outcomes were pooled through either a random-effect model or fixed-effect model according to data heterogeneity. RESULTS: Twenty-four comparative studies either on accelerated cross-linking (AC) compared with SC or on trans-epithelial cross-linking (TC) compared with SC were included and pooled for analysis. The results indicated that MC was significantly inferior to SC at delaying Kmax deterioration [AC vs SC 0.49 (95% CI: 0.04-0.94, I2=75%, P=0.03); TC vs SC 1.15 (95% CI: 0.54-1.75, I2=50%, P=0.0002)]. SE decreased significantly for SC when compared to AC [0.62 (95% CI: 0.38-0.86, I2=22%, P<0.00001)]. DDL of SC was more significantly deeper than that of TC [-133.49 (95% CI: -145.94 to -121.04, I2=33%, P<0.00001)]. Other outcomes demonstrated comparable results between MC and SC. CONCLUSION: SC is more favorable at halting the progression of keratoconus, but visual acuity improvement showed comparable results between MCs and SC.

Cross-sectional investigation of visual impairing diseases in Shanghai blind children school.

BACKGROUND: The control of blindness in children is a high priority within the VISION 2020 initiative. To determine the causes of severe visual impairment and blindness in children from Shanghai Blind Children School (SBCS) can provide useful information on childhood blindness in Shanghai. METHODS: A cross-sectional investigation of students in SBCS was conducted in May 2010. The World Health Organization/Prevention of Blindness (WHO/PBL) eye examination record system for children with low vision and blindness was used. The results were further compared with the findings of two previous investigation studies conducted in 1986 and 2004, respectively in SBCS. RESULTS: Of the 146 children observed, 80 children (54.8%) were blind (best corrected best visual acuity less than 0.05), 27 children (18.5%) had severe visual impairment (best corrected visual acuity less than 0.1 but better than or equal to 0.05), and 34 children (23.3%) had moderate visual impairment (best corrected visual acuity less than 0.3 but better than or equal to 0.1). The major affected anatomic sites in the 107 children with severe visual impairment and blindness (SVI/BL) were retina (47.7%), whole globe (16.8%), optic nerve (13.1%) and lens (9.3%). The leading causes of SVI/BL were retinopathy of prematurity (ROP, 25.2%), followed by retinal dystrophy (15.9%), optic nerve atrophy (9.3%) and microphthalmos (9.3%). The two leading etiologic categories of SVI/BL were perinatal/neonatal (36.4%) and congenital/hereditary groups (29.0%). The leading cause of moderate visual impairment was aphakia after cataract surgery (congenital cataract, 44.1%). Compared with the findings in two previous investigations in SBCS, the proportion of ROP in visual impairing diseases increased, while the proportion of disorders of the lens (cataract and aphakia) significantly decreased. CONCLUSIONS: The leading cause of childhood blindness in SBCS nowadays is ROP. It is projected that without improvement in perinatal medical care that ROP will continue to be a major cause of childhood blindness.

Establishment of a rabbit model for keratoconjunctivitis sicca.

PURPOSE: To establish a rabbit model for keratoconjunctivitis sicca (KCS) to study autologous submandibular gland transfer for treating severe KCS. METHODS: In 2 groups of 10 rabbits, left eyes were operated and right eyes were controls. In the trichloroacetic acid-treated group, the lacrimal and harderian glands and nictitating membrane were removed surgically; the palpebral and bulbar conjunctiva were swabbed with 50% trichloroacetic acid. In the non-trichloroacetic acid-treated group, the lacrimal and harderian glands and nictitating membrane were surgically removed. The Schirmer test was performed preoperatively and 1, 2, 3, and 4 months postoperatively. Corneal densities of rose bengal and fluorescein staining were scored every month postoperatively. At 4 months, the cornea and bulbar conjunctiva were removed from operated and control eyes for histopathology. The upper bulbar conjunctiva was used to determine goblet cell density. RESULTS: Compared with preoperative conditions, tear secretion of operated eyes significantly decreased in both groups postoperatively, then gradually increased. Scores for corneal rose bengal and fluorescein staining were higher and conjunctival goblet cell density was lower in the operated eyes than in control right eyes in both groups, but no significant difference was found between the operated eyes of the two groups. Inflammatory histopathologic changes of the cornea and conjunctiva were not found in either of the eyes in the two groups. CONCLUSIONS: A new rabbit model for KCS could be created by either of these methods. Experimental KCS with reduction of tear production was possible with surgical ablation of the lacrimal and harderian glands and nictitating membrane. It is unnecessary to apply trichloroacetic acid to burn the conjunctiva. Our modified incision better exposed the surgical field.