PURPOSE:To investigate the status and detailed structure of Rb gene in primary tumors and somatic cells of patients with retinoblastoma. To identify the character, origin and transmission of oncogenie point mutations. METHODS:DNA hybridization,SSCP analysis and PCR-associated direct sequencing. RESULTS:Among 108 RB patients examined 80 cases were found to have subtle alterations affecting Rb locus,including 44 cases with homozygous Rb point mutations, 20 cases with two independent heterozygous Rb point mutations, 16 cases with heterozygous mutations involved in one allele of Rb gene. Majority of bilateral RB patients and a small fraction of unilateral RB patients were detected to have a germline mutation. In addition the higher frequency of new germline mutation and parental origin of mutation were observed. CONCLUSION :Rb gene is closely associated with retinoblastoma. Two mutation events and resulting inaetivations of both Rb alleles are required for RB tumorigenesis. Based on our own data,the first event is exclusively point mutation. As for the second event,LOH accounts for two third of cases,point mutation for one third of cases. （Chin J Ocul Fundus Dis,1997,13: 12- 16）
ObjectiveTo observe the clinical characteristics of patients with visual impairment caused by fungal sphenoid sinusitis and analyze the influencing factors related to visual prognosis. Methods A retrospective clinical study. From January 2006 to December 2020, 44 patients (55 eyes) with visual impairment caused by fungal sphenoid sinusitis confirmed by imaging and pathological examination in the Department of Ophthalmology of Beijing Tongren Hospital were included in the study. Patients was first diagnosed in the Department of Ophthalmology due to monocular or binocular vision loss, or binocular diplopia, limited eye movement and ptosis. All patients underwent visual acuity examination and fundus color photography. CT examination of paranasal sinus or orbit was performed in 37 cases; magnetic resonance imaging (MRI) of paranasal sinus, brain or orbit was performed in 34 cases. All patients underwent endoscopic sinus opening combined with intrasinus lesion clearance; 14 cases were treated with antifungal drugs after operation. The average follow-up time was 59.61±37.70 months. Comparison of clinical characteristics between invasive and non-invasive fungal sphenoid sinusitis were by χ2 test or Fisher exact test. The influencing factors with P＜0.2 in univariate analysis were selected for multivariate regression analysis. ResultsAmong the 44 patients, there were 19 males and 25 females; the ratio of male to female was 1:1.3; the average age of visual symptoms was 61.48 ± 12.17 years; 23 cases (52.3%, 23/44) suffered from immune dysfunction, including 21 cases of diabetes mellitus. The visual acuity decreased in 33 cases (44 eyes) (75.0%, 33/44). There were 15 cases of binocular diplopia with eye movement disorder (34.0%, 15/44), including 6 cases with visual impairment. The visual acuity of the affected eye was no light perception-0.8. There were 35 cases with headache (79.5%, 35/44). Nasal symptoms were found in 14 cases (31.8%, 14/44). There were 40 and 4 cases of Aspergillus and Mucor infection in sphenoid sinus, respectively. Among the 37 cases who underwent CT examination of paranasal sinus or orbit, there were soft tissue filling in the sinus cavity, including 19 cases of high-density calcification in the sinus cavity (51.4%, 19/37); bone defect of sinus wall were in 24 cases (64.9%, 24/37). There were 26 cases (70.3%, 26/37) of sinus wall osteosclerosis. MRI of paranasal sinus, brain or orbit was performed in 34 cases. T1WI of sphenoid sinus lesions showed low signal, high signal and equal signal in 14, 10 and 9 cases, respectively; T2WI showed high signal, low signal and equal signal in 13, 16 and 2 cases respectively. After enhancement, the lesions were strengthened in 11 cases, no obvious enhancement in 23 cases, and the surrounding mucosa was thickened and strengthened. The lesions involved the orbital apex and cavernous sinus in 18 and 16 cases, respectively; orbital apex and cavernous sinus were involved in 12 cases. Six months after operation, visual acuity was significantly improved in 27 eyes (65.9%, 27/41); visual acuity did not improve in 14 eyes (34.1%, 14/41). Multivariate regression analysis showed that the change of sinus wall osteosclerosis was associated with higher visual acuity improvement rate (odds ratio= 0.089, 95% confidence interval 0.015-0.529, P=0.008). ConclusionsFungal sphenoid sinusitis related visual impairment is relatively common in elderly female patients with low immune function; monocular vision loss with persistent headache is the most common clinical symptom; imaging findings of sphenoid sinus lesions are an important basis for diagnosis. Sphenoid sinus opening combined with sinus lesion clearance is an effective treatment. After operation, the visual acuity of most patients can be improved. The prognosis of visual acuity was relatively good in patients with hyperplasia and sclerosis of sphenoid sinus wall bone.