With the method of PCR-SSCP combined sequencing,we analysed the mutations in the RB1 gene of 10 retinoblastoma samples. All 27 exons of RB1 gene have been examined. The PCR products were digested with some restriction endonuclease to the size of about 200 bp and then denatured into single strands. Loading the single strands of DNA into the 6% polyacrilamide gel,we followed the technology named SSCP to f/nd the abnormal bands in the SSCP gel. After that, the samples found with the abnormal bands in the SSCP gel were amplified again and sequenced to confirm the types and locations of the mutations in the RB1 gene. We have fonnd some kinds of mutations in the RB1 gene. （Chin J Ocul Fundus Dis,1994,10:17-20）
ObjectiveTo observe the clinical effect of vitrectomy with internal limiting membrane peeling and air tamponade in the treatment of idiopathic macular hole (IMH).MethodsA prospective, non-randomized controlled case cohort study. Twenty eyes of 20 patients with IMH in Ophthamology Department of The Second Hospital of Jilin University from September 2016 to January 2017 were included in this study. There were 4 males (4 eyes) and 16 females (16 eyes), with the mean age of 60.60±9.50 years and the mean disease course of 9.55±15.5 months. The stage of macular hole ranged from Ⅱ to Ⅳ. All patients underwent BCVA, intraocular pressure, spectral-domain OCT (SD-OCT) and multifocal ERG examinations. The BCVA examination was performed using the international standard visual acuity chart, which was converted into logMAR visual acuity. The minimum diameter (MIN), bottom diameter (BD), height (H), the defective diameter of ellipsoid zone, the defective diameter of external limiting membrane (ELM) of the macular hole were measured by SD-OCT (German Heidelberg). Then the macular hole index (MHI=H/BD), hole traction index (THI=MD/BD) and hole diameter index (DHI=H/MD) were calculated. The response density in P1 wave was detected by mf-ERG. The logMAR BCVA was 1.18±0.54. There were 5 eyes with less than 400 μm MIN, 13 eyes with 400-700 μm MIN and 2 eyes with over than 700 μm MIN. All the patients were underwent vitrectomy with internal limiting membrane peeling and air tamponade. According to the SD-OCT image features after surgery, IMH closure was divided into type Ⅰ closed, type Ⅱ closed and unclosed. The follow-up was equal or greater than 3 months. The closure rate of IMH, BCVA and the changes of microstructure parameters of macular area were observed. Spearman correlation analysis was used to analyze the correlation between BCVA and the wave response density in P1 before surgery and the efficacy after IMH surgery.ResultsClosure rate of IMH: 18 eyes (90.0%) were completely closed (all type Ⅰ closed). The closure rate of macular hole with the MIN less than 400 μm was 100.0% (5/5), 400-700 μm was 92.3% (12/13), and over than 700 μm was 50% (1/2). BCVA: the mean logMAR BCVA at 1 week, 1 month, 3 months after surgery were 0.83±0.54, 0.65±0.41, 0.48±0.34, and there was statistically significant difference between preoperative and postoperative BCVA (t=3.382, 4.459, 5.250; P=0.003, 0.007, 0.004). The outcomes of SD-OCT at 3 months after surgery: 18 eyes (90.0%) with intact ELM. The defective diameter of ellipsoid zone was 260.34±272.08 μm, there was statistically significant difference between before and after surgery (t=13.545, P=0.002). The outcomes of mf-ERG: the P1 wave response density of the ring 1 and ring 2 after surgery were increased compared with before surgery (t=-16.748, -6.151; P＜0.01,＜0.01). The results of Spearman correlation analysis: there was a positive correlation between postoperative BCVA and preoperative MIN, the defective diameter of ellipsoid zone and ELM, and postoperative the defective diameter of ellipsoid zone (r=0.56, 0.59, 0.68, 0.52; P=0.010, 0.006, 0.001, 0.019). The postoperative BCVA was negatively correlated with the P1 wave response density of ring 1 and ring 2 of mf-ERG (r=－0.34, －0.16; P=0.006, 0.020). The IMH closure had a significant negative correlation with MIN and the defective diameter of ELM (r=－0.449, －0.449; P=0.047, 0.047). MHI and THI were positively correlated with the closure of the hole (r=0.474, 0.546; P=0.035, 0.013). Intraocular pressure increased in 2 eyes during the follow-up period, and returned to normal within 1 week after the administration of antihypertensive drugs. There were no complications during or after the operation.ConclusionsVitrectomy with internal limiting membrane peeling and air tamponade in the treatment of IMH is safe and effective. The MIN, MHI THI are significantly correlated with the curative effect after IMH surgery, which could be used as the index to predict and evaluate the curative effect. The response density of ring 1 and ring 2 in P1 wave of mf-ERG is signifi-cantly improved compared with before surgery, and which is negatively correlated with BCVA.