Biomedical subjects

Longshan Chen

Publications and source records attributed to Longshan Chen.

6 recordsLinked to original sources

PubMed2003

Microsurgical treatment of Mooren's corneal ulcer.

This study evaluated the effect of microsurgery of lamellar keratoplasty (LKP) on Mooren's corneal ulcer. The surgical effect, postoperative astigmatism, postoperative vision, postoperative ulcer recurrence, and surgical complications of 2 groups of consecutive Mooren's ulcer inpatients treated respectively by non-microsurgery of LKP and microsurgery of LKP were analyzed. There were significant differences of the effect, postoperative astigmatism, postoperative vision, postoperative ulcer recurrence, and surgical complications between the 2 groups. The effect and postoperative vision of the microsurgery-treated group were better than those of the non-microsurgery-treated group. The postoperative astigmatism, postoperative ulcer recurrence, and surgical complications of the microsurgery-treated group were less than those of the non-microsurgery-treated group. Microsurgery of LKP of Mooren's corneal ulcer can greatly improve the cure rate of the disease and postoperative vision, and reduce surgical complication and postoperative ulcer recurrence.

Adolescent↗

PubMed2003

Fresh amniotic membrane transplantation combined lamellar keratoplasty for patients with recurrent Mooren's ulcer.

PURPOSE: To investigate the possibility of amniotic membrane as an immunological insulating band to reduce the recurrent frequency of Mooren's ulcer. METHODS: Twelve cases(12 eyes) with recurrent Mooren's Ulcer were observed. Among them, 4 cases (4 eyes) were male and 8 cases(8 eyes) female, ranging in age between 26 and 51 years [mean(41 +/- 3) years]. Three eyes recurred once, 5 eyes twice, and 4 eyes three before. Eleven of 12 cases (11/12 eyes) with frequently recurrent Mooren's ulcer underwent lamellar keratoplasty combined amniotic membrane transplantation (AMT). One patient who had entire corneal ulceration accepted AMT alone. RESULTS: Follow-up time is 12 to 29 months, [mean (23 +/- 6) months]. Before AMT, the recurrent frequency of Mooren's Ulcer of all cases after corneal surgery was 1-7 months [mean (3 +/- 2) months]. Nine of 12 eyes with lamellar keratoplasty combined AMT did not recur within the observation period; 2 eyes recurred 11 months after the surgery. Three months postoperatively, neovascularization was observed, which made it nearly impossible to decipher between amniotic membrane and its nearby conjunctiva, only at the junction of the transplant can some trails be observed. One case with entire AMT alone showed graft resolution and neovascularization in 1 month. CONCLUSION: AMT combined with lamellar keratoplasty and lesion excision may delay recurrence of Mooren's Ulcer, reduce its recurrent frequency. Besides the effects of decreasing inflammation, it may have immunological insulating function as well. This conclusion should be proven by further clinical comparative study of much more samples.

Adult↗

PubMed2003

[Confocal microscopy in transplanted human corneas].

PURPOSE: The aim of the study was in-real time observation and morphological evaluation of the transplanted human corneas, using confocal 2.0 microscopy. METHODS: Twelve eyes of 12 patients on 3-7 days after lamellar keratoplasty (LKP), 8 eyes of 8 patients at 1 year after LKP, and 10 eyes of 10 patients at 3-7 days after penetrating keratoplasty (PKP), 11 eyes of 11 patients at 1 year after PKP were examined by confocal 2.0 microscopy in vivo. Images were recorded by continuously focusing the optical section through the full thickness central cornea. RESULTS: 3-7 days after LKP, small stromal cells, cranny-like dark strias and nerves were seen in transplanted corneas. There were highly reflective regions and dots in the lamellar interface. One year after LKP, the nerves disappeared. There were less highly reflective regions, but the dots still can be seen. Some gross dark strias were seen in the posterior stroma and the density of the endothelium cells was normal. 3-7 days after PKP, keratocytes were activated. Nerves and gross dark strias could be seen in transplanted corneas. The density of the endothelium cells was normal, with some highly reflective dots deposited among them. One year after PKP, the nerves disappeared, and strias still existed. The density of the endothelium cells decreased significantly. CONCLUSIONS: Confocal scanning microscopy is a new tool for the study of cellular morphology and construction of transplanted human corneas. It can be used in the evaluation of operation effect, clinical observation and follow-up.

Adult↗

PubMed2002

[The contralateral eye in patients with unilateral iridocorneal endothelial syndrome].

OBJECTIVE: To study the clinical characteristics of the contralateral eyes in patients with unilateral iridocorneal endothelial syndrome (ICE). METHODS: The clinical characteristics were analyzed retrospectively on the contralateral eyes in 42 cases of unilateral ICE. Among them, 19 patients (19 eyes) received examinations of refraction, intraocular pressure (IOP), slit lamp, gonioscopy and ultrasound biomicroscopy. In the 35 cases (35 eyes), the endothelial cell counts of the contralateral eyes were compared with age-matched normal controls using t-test. RESULTS: In the 19 cases of unilateral ICE syndrome, emmetropia or hypermetropia were found in 88.9%, IOP higher than 21 mm Hg was present in one case, and anterior chamber depth lower than 2.2 mm was in 50.0%. Atrophy or dysplasia of iris existed in 3 cases, there were narrowness and/or adhesion of anterior chamber angle in 3 cases and pyramidal adhesion under gonioscopy and/or ultrasound biomicroscopy examination in 2 cases. One case represented relative paracentral scotoma in the visual field examination. Systematic disorders, including hepatitis B, diabetes, hyperthyroidism, duodenum ulceration, hypertension were found in 31.6%. In the 35 patients who received endothelial cell count, the average endothelial cell density of the contralateral eyes was (2 593.4 +/- 432.7)/mm(2), which was significantly lower than that of the normal controls (2 784.9 +/- 280.6)/mm(2) (t = -2.43, P = 0.019). The hexagonality and coefficient variation of cell size of ICE patients did not differ from that of the normal controls. CONCLUSIONS: The contralateral eye in cases diagnosed as unilateral ICE syndrome may be subclinically involved, so it is necessary to pay attention to the contralateral eye, and follow up all the patients suffered from ICE syndrome.

Adult↗

PubMed2002

[Corneal topography and thickness in keratoconus].

OBJECTIVE: To evaluate the corneal topography and pachymetry in keratoconus. METHODS: Thirty-five patients (47 eyes) with keratoconus were evaluated by Orbscan corneal topography system. The location, anterior and posterior surface elevation, curvature and pachymetry were analyzed with special reference to the central point of cornea, the apex, the highest point of posterior surface, the point with greatest curvature and the thinnest point. The correlation between the point of greatest curvature and the apex was also analyzed. RESULTS: The mean elevation of the apex was (0.102 +/- 0.044) mm, the mean distance between the apex and the central point of cornea was (0.686 +/- 0.376) mm. Most of the apexes, the points with the highest posterior surface, the points with the greatest curvature were located in the inferior temporal quadrant, followed by inferior nasal, superior temporal and superior nasal quadrant. The SimK of keratocunus was (60.9 +/- 10.4/53.4 +/- 8.7) D and the mean powers within 3 mm and 5 mm were (57.1 +/- 8.0) D and (50.7 +/- 5.4) D respectively. High correlation between apex elevation and the apex curvature was found (r = 0.697, P < 0.01), and there was also negative relationship between apex elevation and corneal thickness (r = -0.563, P < 0.01). CONCLUSIONS: The Orbscan system can provide accurate and subtle information about the shape and thickness of keratoconus, which can help us to learn this disorder deeply, especially in the early diagnosis of this disease.

Adolescent↗

PubMed2002

[Expression of vascular endothelial growth factor and its receptors (flt-1) in morbid human corneas and investigation of its clinic importance].

PURPOSE: To investigate the expression of vascular endothelial growth factor (VEGF) and its receptor (flt-1) in morbid corneas and the potential effects. METHODS: Eleven cases of normal peripheral corneas and limbal tissues and 32 cases of miscellaneous morbid corneas were collected during corneal transplantation. The specimens were sectioned in a cryostat and stained with streptavidin-biotin-peroxidase method for VEGF and flt-1. The expressive levels of VEGF were compared with grades of patients' clinical manifestations. RESULTS: Positive expression of VEGF was exclusively presented in all morbid corneal specimens and that of flt-1 was showed in most cases. Stronger staining was found in the epithelia and stoma of the morbid cornea. The expressive levels of VEGF were more important in the stroma and the endothelia of the morbid corneas than that in the normal peripheral corneas and were positively correlated with the degrees of corneal opacities and the area of corneal neovascularization in infiltrating inflammatory cells and proliferative tissues ( P < 0. 05). CONCLUSIONS: VEGF and flt-1 were expressed in miscellaneous morbid corneas and may play an important role in the repair of corneal injuries and the corneal neovascularization.

Cornea↗