ABSTRACT
PURPOSE: To compare electroretinogram (ERG) waveforms acquired using a ganzfeld stimulator and a Fresnel ganzfeld stimulator. METHODS: ERGs were recorded with a ganzfeld stimulator and a Fresnel ganzfeld stimulator from both eyes of 25 volunteers. Peak-to-trough amplitudes and peak implicit times were compared between both eyes and between a ganzfeld stimulator and a Fresnel ganzfeld stimulator. ERGs taken from the sitting and supine positions were also compared using the Fresnel ganzfeld stimulator. RESULTS: There was no statistically significant difference between the Fresnel ganzfeld stimulator and dome-shaped ganzfeld stimulator in amplitude and implicit time of dark adapted 0.01, 3.0 ERG, photopic 3.0 ERG, photopic 3.0 flicker. The differences in amplitude and implicit time between the right and left eyes were not influenced by the Fresnel ganzfeld stimulator. Additionally, no differences were observed in ERGs obtained from the sitting and supine positions using the Fresnel ganzfeld stimulator. CONCLUSIONS: The newly developed ganzfeld stimulator with a sealed Fresnel lens can be considered as a reliable alternative method for measuring ERGs. Fresnel ganzfeld stimulator is useful for patients having problems with mobility or uncooperative children.
Subject(s)
Child , Humans , Supine Position , VolunteersABSTRACT
PURPOSE: This study investigated the surgical outcomes of canalicular trephination combined with endoscopic dacryocystorhinostomy (DCR) in patients with a distal or common canalicular obstruction. It also identified the factors affecting surgical success rates associated with this technique. METHODS: We retrospectively reviewed the medical records of 57 patients (59 eyes) in whom a canalicular obstruction was encountered during endoscopic DCR. All patients were treated with endoscopic DCR, followed by canalicular trephination and silicone tube placement. The surgical outcome was categorized as a functional success according to the patient's subjective assessment of symptoms, including epiphora, and as an anatomical success according to a postoperative nasolacrimal duct irrigation test. Surgical success rates were compared based on age, sex, location of the obstruction, number of silicone tubes, and experience of the surgeon. RESULTS: Functional success was achieved in 55 of 59 eyes (93%) at one month, 50 eyes (84%) at three months, and 46 eyes (78%) at six months. Anatomical success was achieved in 58 of 59 eyes (98%) at one month, 52 eyes (88%) at three months, and 50 eyes (84%) at six months. There was a statistically significant difference in surgical outcome according to the experience of the surgeon. The anatomical success rate at the six-month follow-up exam was 95.4% in the >5 years of experience group, and 53.3% in the <5 years of experience group (p = 0.008, Pearson chi-square test). CONCLUSIONS: The success rate of canalicular trephination combined with endoscopic DCR in patients with a distal or common canalicular obstruction decreased gradually during the six-month follow-up period. In particular, patients undergoing procedures with experienced surgeons tended to show excellent surgical outcomes at the six-month follow-up exam.