Biomedical subjects

Pei-Yu Lin

Publications and source records attributed to Pei-Yu Lin.

10 recordsLinked to original sources

PubMed2006

Corneal lesion as the initial manifestation of tyrosinemia type II.

Tyrosinemia type II (Richner-Hanhart syndrome) is a rare autosomal recessive disease with deficiency of tyrosine aminotransferase and subsequently increasing level of serum tyrosine. We report the case of a 2-year-old girl who was referred due to bilateral corneal lesions. Slit-lamp examination showed small granular white deposits arranged in a dendritic pattern in the superficial central cornea of both eyes. Physical examination revealed painful, non-pruritic, hyperkeratotic plaques on the soles, palms and fingertips. Mental evaluation demonstrated developmental delay for her age. Blood examination revealed serum tyrosine level to be 1868 microM (normal range, 30-110 microM), which decreased to 838 microM with 2-month diet on tyrosine and phenylalanine restriction. The corneal and skin lesions resolved completely. However, the corneal deposits recurred a month later as her mother failed to strictly control the diet because the little girl was losing weight and activity. With specific formula and adjusted diet regimen, the corneal lesions decreased again. Corneal pseudodendritic deposits may be the initial manifestation in patients with tyrosinemia type II. Early diagnosis and intervention with diet control are crucial for preventing permanent visual and developmental deficits. Corneal deposits can be one of the parameters in monitoring the efficacy of diet control.

Child, Preschool↗

PubMed2005

Type II collagen gene variants and inherited osteonecrosis of the femoral head.

BACKGROUND: Avascular necrosis of the femoral head (ANFH) causes disability that often requires surgical intervention. Most cases of ANFH are sporadic, but we identified three families in which there was autosomal dominant inheritance of the disease and mapped the chromosomal position of the gene to 12q13. METHODS: We carried out haplotype analysis in the families, selected candidate genes from the critical interval for ANFH on 12q13, and sequenced the promoter and exonic regions of the type II collagen gene (COL2A1) from persons with inherited and sporadic forms of ANFH. RESULTS: We identified a G-->A transition in exon 50 of COL2A1 in affected members of a four-generation family with ANFH. This transition predicts the replacement of glycine with serine at codon 1170 in a GXY repeat of type II collagen. Another pedigree was shown to harbor the same transition, but the mutant allele occurred on a different haplotype background. In a third family, a G-->A transition in exon 33 of the gene, causing a glycine-to-serine change at codon 717, was detected. No mutation was found in the COL2A1 coding region in sporadic cases of ANFH. CONCLUSIONS: All the patients with familial ANFH whom we studied carried COL2A1 mutations. In families with ANFH, haplotype and sequence analysis of the COL2A1 gene can be used to identify carriers of the mutant allele before the onset of clinical symptoms, allowing the initiation of measures that may delay progression of the disease.

Adult↗

PubMed2005

Central corneal mosaic opacities in Schnyder's crystalline dystrophy.

PURPOSE: To report an unusual presentation of Schnyder's corneal crystalline dystrophy (SCCD), sharing the feature of central corneal mosaic opacities. DESIGN: Observational case report. METHODS: A 51-year-old man and his family members were examined. Investigations included slit-lamp biomicroscopy, radiography of knee joint, plasma lipid level, and genotyping of the SCCD candidate region in chromosome 1p34.1-1p36. RESULTS: A symmetric, central, disciform, full-thickness opacity was seen in both corneas of the patient. The opacities appeared in a mosaic pattern, instead of collections of crystals or a diffuse haze as typically detected in SCCD. Small clumps of crystalline deposits and arcus lipoides were also observed. Systemically, hyperlipidemia and bilateral genu valgus were identified. He had 2 daughters, and both of them had bilateral corneal crystalline deposits and genu valgus. No other family members had findings suggesting SCCD. The genetic study demonstrated that all of the affected individuals shared a common haplotype within the region of previously reported SCCD locus. However, 1 unaffected sibling of the proband also had the same haplotype. CONCLUSIONS: Central corneal mosaic opacities may be another variant of SCCD.

Adolescent↗

PubMed2005

Orbital metastatic osteosarcoma.

A 15-year-old girl with right tibial osteosarcoma, diagnosed 22 months previously, developed right orbital and skull base metastases, with symptoms including painful protrusion of the right eyeball and severe visual impairment. She underwent embolization of the metastatic tumor, local irradiation, and chemotherapy followed by intralesional resection of the mass because extensive involvement of the skull base precluded complete surgical resection. The best corrected visual acuity in her right eye initially decreased to 20/200, then dropped to no light perception after embolization, and then improved to counting fingers at 50 cm after radiotherapy. The symptoms of pain and proptosis subsided completely. After 24 months of follow-up from the presentation of orbital metastasis, the patient's right-eye vision remained unchanged. The surgical specimen revealed a necrotic tumor similar to osteosarcoma. In conclusion, orbital metastasis of osteosarcoma is rare, but may lead to severe visual impairment. Combined radiotherapy, chemotherapy and surgery can partially relieve symptoms, but cannot completely eradicate the tumors.

Adolescent↗

PubMed2005

Association between symptoms and signs of dry eye among an elderly Chinese population in Taiwan: the Shihpai Eye Study.

PURPOSE: To analyze the association between dry-eye symptoms and signs in an elderly Chinese population in Taipei, Taiwan. METHODS: The participants were those of the Shihpai Eye Study, a population-based survey of eye diseases in the elderly (> or =65 years) in Shihpai, Taipei, Taiwan. Of 2045 randomly selected noninstitutionalized residents, 1361 (66.6%) participated in the study. Dry-eye symptoms were evaluated with an interviewer-administered questionnaire. Dry-eye signs, including tear-film breakup time, Schirmer test result, score for fluorescein staining of the cornea, and meibomian gland dysfunction, were assessed. Correlations between symptoms and signs were analyzed. RESULTS: Of the participants, 33.7% (459/1361) were symptomatic, defined as reporting one or more symptoms often or all the time. A Schirmer result of < or =5 mm was the only sign associated with frequent symptoms (P = 0.028). Its sensitivity and specificity in detecting symptomatic subjects were 62.5% and 43.7%, respectively. The agreement between each sign was statistically significant, although weak, except that no correlation was found between the Schirmer result and meibomian gland anomalies. Of the symptomatic subjects, 85.4% (392/459) had either a low Schirmer result or a meibomian gland anomaly; 38.8% (178/459) of them were abnormal on both tests. CONCLUSIONS: The Schirmer test was shown to be incapable of detecting meibomian gland disease. However, a low Schirmer result was significantly associated with dry-eye symptoms in this elderly Chinese population. This result differs from that of previous reports of elderly white populations. Further studies are needed to determine whether this difference indicates racial diversity in the distribution and behavior of dry-eye diseases.

Aged↗

PubMed2004

Autosomal dominant avascular necrosis of femoral head in two Taiwanese pedigrees and linkage to chromosome 12q13.

Avascular necrosis of the femoral head (ANFH) is a debilitating disease that commonly leads to destruction of the hip joint in adults. The etiology of ANFH is unknown, but previous studies have indicated that heritable thrombophilia (increased tendency to form thrombi) and hypofibrinolysis (reduced ability to lyse thrombi), alcohol intake, and steroid use are risk factors for ANFH. We recently identified two families with ANFH showing autosomal dominant inheritance. By applying linkage analysis to a four-generation pedigree, we excluded linkage between the family and three genes related to thrombophilia and hypofibrinolysis: protein C, protein S, and plasminogen activator inhibitor. Furthermore, by a genomewide scan, a significant two-point LOD score of 3.45 (recombination fraction [theta] = 0) was obtained between the family with ANFH and marker D12S85 on chromosome 12. High-resolution mapping was conducted in a second family with ANFH and replicated the linkage to D12S368 (pedigree I: LOD score 2.47, theta = 0.05; pedigree II: LOD score 2.81, theta = 0.10). When an age-dependent-penetrance model was applied, the combined multipoint LOD score was 6.43 between D12S1663 and D12S85. Thus, we mapped the candidate gene for autosomal dominant ANFH to a 15-cM region between D12S1663 and D12S1632 on chromosome 12q13.

Adolescent↗

PubMed2004

Ocular injuries from plant sap of genera Euphorbia and Dieffenbachia.

Clinical findings in 3 cases of ocular injuries caused by the milky latex from Euphorbia tirucalli and Dieffenbachia sequine were reported. The initial symptoms of all patients were burning pain with subsequently blurred vision. Visual acuity was reduced between 6/30 and 6/20. Euphorbia sap caused punctate erosion, microbullae and Descemet's folds; while Dieffenbachia sap induced conjunctival chemosis and fine blue crystals in the stroma. Ocular symptoms developed in 5 to 18 hours despite immediately copious irrigation. Supportive treatment resulted in a full recovery without sequalae over 1 week. Wearing eye protection and washing the exposed areas with soap and water are advised while handling such plants.

Adult↗

PubMed2003

Prevalence of dry eye among an elderly Chinese population in Taiwan: the Shihpai Eye Study.

PURPOSE: To describe the epidemiology of dry eye in an elderly Chinese population in Taipei, Taiwan. DESIGN: A population-based cross-sectional study. PARTICIPANTS: The Shihpai Eye Study was a population-based survey of eye diseases in the elderly (> or =65 years) in Shihpai, Taipei, Taiwan. Noninstitutionalized residents, as of July 1999, were identified by using the official household registration database. A total of 2045 subjects were selected, and 1361 (66.6%) people participated in the study. Among them, 822 (60.4%) were men. METHODS: Trained interviewers administered a standardized questionnaire pertaining to dry-eye symptoms. Objective examinations of dry eye included tear film breakup time, Schirmer test, fluorescein stain of the cornea, and anatomic assessment of the meibomian glands via slit-lamp biomicroscopy. MAIN OUTCOME MEASURES: Frequency of dry-eye symptoms and positive dry-eye tests. RESULTS: In this population, 33.7% (459/1361) were symptomatic, defined as reporting 1 or more dry-eye symptoms often or all of the time. Women were more likely to report frequent symptoms of dry eye (odds ratio, 1.49; 95% confidence interval, 1.19-1.87). Among those who were symptomatic, 78.9% (362/459) had a low tear film breakup time (< or =10 seconds), 62.5% (287/459) had a low Schirmer test result (< or =5 mm), and 61.7% (283/459) had abnormal anatomic features of the meibomian glands. Furthermore, 85.4% (392/459) were symptomatic and had either a low Schirmer score or an abnormal meibomian gland assessment. Of those symptomatic, 49.9% (229/459) indicated that they had visited an eye doctor, 5.4% (25/459) responded that they had been diagnosed with dry eye, and 47.5% (218/459) reported current use of eyedrops. CONCLUSIONS: This is the first report of population-based data of dry eye that includes symptoms and signs in elderly Asians. The prevalence of dry eye, although varied according to definition, is relatively higher in this study than that reported for whites. Further studies are needed to determine whether this is due to racial or environmental factors.

Age Distribution↗

PubMed2003

Localized amyloidosis of the cornea secondary to trichiasis: clinical course and pathogenesis.

PURPOSE: To present four cases of localized corneal amyloidosis secondary to trichiasis and to discuss its pathogenesis. METHODS: Medical and pathologic records of four patients with corneal amyloidosis secondary to trichiasis were reviewed retrospectively. Two patients underwent trichiasis surgery and then lamellar keratectomy. One patient underwent trichiasis surgery only, and one patient received keratectomy only. The excised specimens were examined by light and electron microscopy. In two cases, they were stained with antibodies against kappa and lambda immunoglobulin light chains. All patients were followed for evidence of progression or recurrence of the lesions. RESULTS: Three cases presented with blurring of vision and a progressively enlarging vascularized unilateral corneal mass. One case had normal vision and a smaller, nonvascularized mass. All four cases had a history of trichiasis. After trichiasis surgery but before corneal surgery, two patients were followed for 24 and 18 months, respectively, and showed no progression of the corneal lesions. The patient who did not undergo trichiasis surgery had a recurrence of the corneal lesion after lamellar keratectomy. Pathologic examination confirmed amyloid deposition in all three excised specimens with almost no inflammatory cells. Immunohistochemical stains were negative. CONCLUSION: The close correlation between trichiasis surgery and the clinical course of corneal amyloidosis provides further evidence for their association. The pathologic findings in this study do not confirm that the amyloid deposits are light chain proteins (AL).

Adolescent↗

PubMed2002

Allelic and locus heterogeneity in autosomal recessive gelatinous drop-like corneal dystrophy.

Gelatinous drop-like corneal dystrophy (GDLD) is a rare autosomal recessive disease characterized by the deposition of amyloid beneath the corneal epithelium and by severely impaired visual acuity leading to blindness. Although gelatinous corneal dystrophy has previously been mapped to chromosome 1p and seems to be associated with mutations in the M1S1 gene, molecular genetic studies have been limited to Japanese patients. To investigate the cause of GDLD in patients with diverse ethnic backgrounds, we performed linkage analyses in eight unrelated GDLD families from India, USA, Europe, and Tunisia. In seven of these families, the disease locus mapped to a 16-cM interval on the short arm of chromosome 1 between markers D1S519 and D1S2835, a region including the M1S1 gene. In addition, a 1.2-kb fragment containing the entire coding region of M1S1 gene was sequenced in affected individuals. Seven novel mutations (M1R, 8-bp ins., Q118 E, V194 E, C119 S, 870delC, and 1117delA) were identified in six families and two unrelated individuals. No sequence abnormalities were detected in a single family in which the GDLD locus was also excluded from the M1S1 region by linkage analysis. These findings demonstrate allelic and locus heterogeneity for GDLD.

Alleles↗