Objective To observe the effect of the treatment of neodymium-yttrium aluminum garne (Nd:YAG) vitreolysis for the anterior vitreous opacity after implantation of intraocular lens.Methods Forty-nine eyes of 47 patients with the anterior vitreous opacity after implantation of intraocular lens received the slitlamp examination, optical coherence tomography (OCT), and B-scan. The anterior vitreolysis and posterior capsulotomy were performed simultaneously with Nd :YAG laser. The outcomes of visual acuitiy changes and complications were studied.Results In 49 eyes, 46 had anterior vitreous opacity associated with posterior capsule opacification, and the other 3 without obvious posterior capsule opacification. In all patients, the visual acuity improved significantly without any complications after the laser procedure (t=32.50, P=0.007). After Nd:YAG laser treatmen, transparent area was found in anterior opaque vitreous in 21 eyes (42.86%) within 15 minutes, and in 47 eyes (95.92%) within 24 hours. No complication occured in or after the operation.Conclusions In the patients with visual deterioration after implantation of intraocular lens, the prescence of anterior vitreous opacity should be concerned. Opening the opaque anterior vitreous with Nd:YAG vitreolysis is effective for the patients with the anterior vitreous opacity after implantation of intraocular lens.(Chin J Ocul Fundus Dis，2003，19：106-108)
Objective To evaluate the effect of the treatment of diode laser for retinopathy of prematuriy (ROP).Methods Six-eight premature infants, with the gestation lt;32 weeks and birth weight lt;1500 g,were examined 6-7 weeks after birth. The infants suffering from threshold ROP were treated by diode laser through a binocular indirect ophthalmoscope within 48 hours after the confirmation of diagnosis, and with the follow-up of 4～6 moths. Retinal detachment was found in 1 eye 1 month after laser treatment, and scleral encircling operation was performed on the eye which was followed up for 3 months after the operation. Cycloplegic refractive examination was performed on the eyes with threshold ROP 4 months postnatally to determine the presence of refractive errors.Results Six infants (1) eyes were diagnosed as with threshold ROP. The average age of the occurrence of threshold ROP were (10±2.89) (ranging from 6 to 14 weeks) weeks postnatally. The successful rate of diode laser treatment was 91.67%. Retina was flat in one eye treated by scleral encircling operation. Refractive errors of the eye treated by scleral encircling operation was -14.5 D, and the median spherical equivalent errors in other 11 eyes was ( -2.89±-1.86) D. Conclusion The treatment of diode laser is effective for threshhold ROP. (Chin J Ocul Fundus Dis，2003，19：96-98)
Objective lt;brgt;To inspect the rate of success of anastomosis and tissue damage with different power levels of photocoagulation in the treatment of experimental branch retinal vein occlusion (BRVO) by laser induced chorioretinal venous anastomosis. lt;brgt;Methods lt;brgt;Forty pigmented rabbits (80 eyes) were divided into four groups in random, and 10 (20 eyes) in each. Chroioretinal venous anastomosis was attempted to create using the krypton red laser with 4 different power levels (group A: 400 mW,group B: 600 mW,group C: 800 mW,group D: 1000 mW) in these animals in which BRVO had previously been created photodynamically. Fundus photography and fundus fluorescein angiography were performed at various times after the treatment and histological examination was taken at the end of the study. lt;brgt;Results lt;brgt;The model of BRVO was successfully set up. At the lowest power of 400 mW there was an absence of anastomosis formation and the damage to the retina and choroid was mild, Bruch′s membrane showed no evidence of rupture. At the power levels of 600 mW and 800 mW an anastomosis formed in 15% and 55% respectively and the damage was medium in degree. At the highest power level of 1 000 mW a 80% rate of success was obtained, however, the damage to the retina and choroid tended to be severe.The difference of the rate of success of anastomosis between different groups was highly significant (P=0.001), the difference between group B and group C was also highly significant (PBC=0.008), and the difference between group A and group B, group C and group D was not significant (PAB=0.072、PCD=0.091). lt;brgt; lt;brgt;Conclusion lt;brgt;The optimal power level of krypton red laser induced chorioretinal venous anastomosis is 800 mW, 0.1 s, 50 μm in our study. lt;brgt; lt;brgt;(Chin J Ocul Fundus Dis,2002,18:13-16)
Objective To evaluate the effective method for treatment of premacular hemorrhage. Methods In 36 cases (36 eyes) of premacular hemorrhage (2PD),25 cases were treated with medicine, and 11 cases were treated with laser surgery and medicine. Results In 25 patients treated with medicine, the average time of vision recovery was 24 days and the average time of clearance of vitreous hemorrhage was 40 days; in the other 11 patients treated with laser surgery and medicine,10 were treated successfully, and in these 10 patients, the average time of vision recovery were 5 days and the average time of clearance of premacular hemorrhage were 11 days in 10 cases which were operated successfully with laser in 11 cases. Conclusions Laser surgery of inducing preretinal hemorrhage to vitreous body is an effective method for treatment of premacular hemorrhage to relieve the impaired central vision. (Chin J Ocul Fundus Dis, 2002, 18: 199-201)
Objective To investigate the early influences of laser photocoagulation on retinal function in diabetic retinopathy(DR)． Methods The multifocal electroretinograms (MERG) of 30 eyes with DR (phase Ⅲ～Ⅳ) were tested with visual evoked response image system IV b efore,and the 3rd day and the 7th day after laser photocoagulation． Results Three days after photocoagulation, the latency of N1 prolonged in the central macula 5deg; area and superionasal quadrant．Th e response densities of N1,P1 and N2 markedly reduced, and most significant changes occurred in the central macula 5deg; area and then in the central 10deg;area． There were also differences in the changes of the amplitude of N1 and P1 in diff erent quadrants ．The changes of visual acuity were positively related to the de crease of amplitudes of N1,P1 and N2 in the macula． Conclusion The reduction of response densities in MERG reveals functional damage in diabetic retina occurring early after photocoagulation．The functional damage in macula induced indirectly by photocoagulation may explain the reduction of visual acuity after panretinal photocoagulation in some degree． (Chin J Ocul Fundus Dis, 2001,17:181-183)
Objective To investigate the therapeutic effects of retinal angioma. Methods The clinical data of 16 cases(20 e yes) were retrospectively analyzed, and the patients included 5 males and 11 females of 23.3 yeras old on average. Four cases in this series affected by bilateral retinal angiomas were identified as von Hippel-Lindou disease. The retinal an giomas were divided into 5 stages according to their degrees of developmnet from simple angiom without vessel dilation to feeder vessel dilation and intraretina l exudates, local retinal detachemnt, massive retinal detachment and complication occurrence in proper order. The methods of treatment were laser photocoagulati on, trans-scleral cryotherapy and vitreoretinal surgery. The patinets were followed up for 37.8 months on average. Results There were 10 eyes (2 in stage 1, 7 in stage 2, 1 in stage 3)treated with laser photocoagulation, and all of the angiomas were controlled after the treatment. The visual acuity im proved in 2 eyes, decreased in 4 eyes, and remained unchanged in 4 eyes. Cryothe r apy was performed on 7 eyes(5 in stage 3, 2 in stage 4). The visual deteriortion was found in 5 eyes; and the state of illness was stable in 3 eyes in stage 3 a nd aggravating in 4 eyes (2 in stage 3, 2 in stage 4). Vitreoretinal surgery was performed on 4 eyes including 2 which had been given photocoagulation, and the visual acuity improved in 2 eyes, decreased in 1 eye, and was unimproved in 1 ey e . The visual acuity decreased to no light perception in an untreated eye after 1.5 year follow-up. New angiomas occurred in 3 eyes with Von Hippel-Lindou disease in the follow-up period. Conclusion Laser photocoagulation is effective in treating the angiomas from stage 1 to 3. Cryotherapy can cause massive exudation and proliferation, and it is only suitable for a few patients in stage 3. The visual prognosis is more favorable in vitreoretinal surgery tha n other therapies for the patients in stage 4. (Chin J Ocul Fundus Dis, 2001,17:296-298)
Purpose To study an animal model of retinal sheets transplantation using excimer laser. Methods A layer of pure photoreceptors was got by the use of excimer laser.Then the photoreceptor layer was transplanted to the subretinal space of the adult RCS rats which were an animal model of inherited retinal degeneration.The globes were enucleated one month after transplantation.Sections were made for light microscopic examninations. Results A layer of pure and uniform photoreceptors can be got by the use of excimer laser.The transplanted photoreceptors survived well in the subretinal space. Conclusion Retinal sheets transplantation using excimer laser can provide us with well oriented retinal construction and more photoreceptors after transplantation. (Chin J Ocul Fundus Dis,1998,14:209-211)