Multilayer Amniotic Membrane Transplantation for Corneal Ulcer Perforation

PURPOSE: To evaluate the clinical outcome of multilayer amniotic membrane transplantation (AMT) in the cornea which was perforated or had impending perforation due to corneal ulcer. METHODS: Human multilayer amniotic membrane transplantation were performed in patients with perforation or impending perforation of cornea due to herpetic keratopathy (2 eyes of 2 patients) and fungal ulcer (1 eye). The surgical procedure consists of the following steps: First, all cellular debris was carefully removed from the base and the walls of the ulcer and loosened epithelium. In addition 1 to 2 mm zone is created around the ulcer by removal of healthy, adherent epithelium overlaying the normal Bowman membrane. Depending on the depth and the configuration of the ulcer, three or more of small pieces of human amniotic membranes are stacked one above the others to fill the cavity of the ulcer. Finally, a larger piece of membrane is trimmed to cover the ulcer and then secured with interrupted 10-0 nylon suture. RESULTS: The corneal perforations were prevented and the stable ocular surface were achieved in all patients. CONCLUSIONS: Human multilayer amniotic membrane transplantation is a useful treatment prior to corneal transplantation and considered as an alternative treatment to keratoplasty for perforation or impending perforation of corneal ulcer.

Multifocal Electroretinogram Abnormalities of Central Serous Chorioretinopathy

PURPOSE: To assess retinal electrophysiologic dysfunction in patients with central serous chorioretinopathy (CSC) with multifocal electroretinograms (mfERGs) and full-field electroretinograms (Full-field ERG). METHODS: 24 patients with unilateral CSC and 24 age-similar control group underwent fundus exam, fluorescein angiography, mfERG and full-field ERG. The results of testing of patients with CSC in the affected and fellow eyes were compared with the age-similar normal controls. RESULTS: All of the patients had central macular detachments in the affected eyes, while the fellow eyes were normal. In fluorescein angiography, all of the patients had small, focal hyperfluorescent leak in early phase in the affeted eyes, while the fellow eyes were nonspecific findings. The results of full-field ERG were not significantly different between unilateral CSC patient and normal control group. In mfERG, amplitude of both affected and fellow eyes were significantly decreased in the entire test field of retina comparing with normal controls (P<0.05), while implicit time increased (P<0.05). CONCLUSIONS: Not only affected eyes but fellow eyes of the patients with CSC had abnormal responses in the first order kernel. These results suggested that not only affected but also fellow eyes possibly had underlying pathologic condition as abnormal chorioidal circulation. mfERG may be useful in evaluating the retinal function of affected and fellow eyes with CSC patients.

Multifocal Electroretinograms in Patients with Branch Retinal Vein Occlusion

PURPOSE: To evaluate the damage to the inner retina in patients with branch retinal vein occlusion (BRVO), we recorded multifocal electroretinograms (mfERG) and analyzed the waveform changes of the first and the second order kernel responses. METHODS: Eight eyes of patients with unilateral BRVO were included. Fourteen eyes of 14 normal subjects were also tested as controls. VERIS system was used to record mfERG. The first and the second order kernel responses of each quadrant were averaged. Averaged responses were compared with those of the contralateral eyes and normal control eyes. RESULTS: The amplitudes of averaged tracing decreased in the N1, P1, and N2 of the first order kernel responses in the affected quadrant in comparison with those of contralateral and normal control eyes (P<0.05). Prolongation of latency was noted in N1, P1 and N2 in the affected quadrant. In the second order kernel responses of the affected quadrant, no responses were found in four patients. The delay in latency and the decrease in amplitude were more marked in the second order kernel responses than in the first order kernel responses (P<0.01). CONCLUSIONS: The first order mfERG components decreased in amplitude and increased in latency, with N2 being the most severely affected. And the second order mfERG components were more decreased in the affected area in patients with BRVO. These results suggested that the second order kernel responses may reflect the condition of the inner retina better than the first order kernel responses.

Pneumatic Displacement of Submacular Hemorrhage with Intravitreal Injection of SF6 Gas without Tissue Plasminogen Activator

PURPOSE: To assess the efficacy and safety of intravitreal injection of SF6 gas for the displacement of submacular hemorrhage without use of tissue plasminogen activator (tPA) METHODS: Three hundred microliter of pure SF6 gas 0.3 ml was injected into the vitreous cavity in 9 eyes with submacular hemorrhage involving the fovea because of myopic degeneration (3 eyes), trauma (3 eyes), age-related macular degeneration (2 eyes), macroaneurysm (1 eyes), branch retinal vein occlusion (1 eyes) and myopic degeneration (2 eyes) within 4 weeks after the onset of symptoms. The patients were instructed to maintain a prone position for less than 7 days. RESULTS: Initial visual acuity was ranged from hand motion to 0.2 and visual improvement was found in 7 eyes on the 7th day after the gas injection. On the 7th day after the gas injection, submacular hemorrhage was completely displaced in 2 eyes and slightly displaced with a reduction in the thickness of hemorrhage in 2 eyes. Transient elevation of intraocular pressure occured in 1 eye and was successfully controlled with medications. CONCLUSIONS: Intravitreal SF6 gas injection is simple and can displace submacular hemorrhage without use of tissue plasminogen activator in many cases with no serious complications.

Clinical Applications of Multifocal Electroretinography (mfERG)

PURPOSE: To compare the multifocal electroretinography (mfERG) system to full-field ERGs obtained from patients with known retinal diseases in order to assess its clinical applicability. METHODS: Full-field ERGs, mfERG, fluorescein angiography, visual field examination were performed in normal person and in patients with retinitis pigmentosa, nonischemic central retinal vein occlusion, branch retinal vein occlusion, Vogot-Koyanagi-Harada syndrome, central serous chorioretinopathy, macular degeneration or retinal detachment. RESULTS: The dysfunctional areas measured by mfERG were well compatible to those assumed by findings of full-field ERGs. However, the results of mfERG in the retina with central serous chorioretinopathy were shown abnormal response despite of normal response of full-field ERGs. The results of mfERG in the retina with macular degeneration showed abnormal response although other findings (e.g. Full-filed ERGs, FAG, Fundus ) were normal. CONCLUSIONS: The mfERG system is useful for electroretinographic field mapping and evaluating retinal function clinically.