Intravitreal gas injection without vitrectomy for macular detachment associated with an optic disk pit.

PURPOSE: To evaluate the clinical outcomes after gas tamponade without vitrectomy for retinal detachment associated with an optic disk pit using optical coherence tomography. METHODS: Intravitreal gas injection was performed on 8 consecutive patients (mean age, 35.0 years; range, 15-74 years) with unilateral macular detachment associated with an optic disk pit. A 0.3-mL injection of 100% sulfur hexafluoride 6 gas was carried out without an anterior chamber tap. Patients treated with gas injection were instructed to remain facedown for 5 days. RESULTS: Complete retinal reattachment after only gas tamponade was achieved in four out of eight eyes. The mean number of gas injections was 1.8. The mean best-corrected visual acuity before and after the treatment with gas tamponade was approximately 30/100 and 20/20, respectively. The period required for reattachment after final gas treatment was 12 months. There were no incidences of recurrence after complete reattachment by gas tamponade in any of the cases during the 94-month average follow-up period (range, 64-132 months). CONCLUSION: Gas tamponade appears to be an effective alternative method for macular detachment associated with an optic disk pit, even though the mechanisms of optic disk pit maculopathy are still unknown.

Retinal ganglion cell analysis in multiple evanescent white dot syndrome.

BACKGROUND: Multiple evanescent white dot syndrome (MEWDS) is an acute and usually unilateral retinopathy that occurs predominantly in young adults. This report presents the outcomes of ganglion cell analysis (GCA) in MEWDS. CASE PRESENTATION: A 41-year-old woman was diagnosed as MEWDS in right eye. At her initial visit, the deviation map of the ganglion cell analysis showed there was a decrease of the ganglion cell layer (GCL) + inner plexiform layer (IPL) thickness in both eyes, even though her left eye was not affected. A 29-year-old woman was also diagnosed as MEWDS in right eye. Although the deviation map of ganglion cell analysis showed there was a decrease of the GCL + IPL thickness in both eyes at her initial visit, her right eye was not affected. CONCLUSION: GCA indicated there was a decrease (<1% of the distribution of normals) of the ganglion cell layer + inner plexiform layer thickness in both the affected and fellow eyes in 7 of 9 patients diagnosed as MEWDS in our hospital. Although the lesions responsible for MEWDS are thought to disrupt the photoreceptor outer segments, we observed changes in the inner retina in both the affected and fellow eye of MEWDS patients.

Observation of neovascularization of the disc associated with proliferative diabetic retinopathy using OCT angiography.

PURPOSE: To describe the relationship between the vitreous and the neovascularization of the disc (NVD) using swept source optical coherence tomography (SS-OCT) and OCT angiography (OCTA). STUDY DESIGN: Retrospective. METHODS: We examined 17 eyes of 11 consecutive patients diagnosed as NVD associated with proliferative diabetic retinopathy (PDR). The location of the NVD feeder or collector vessels were examined by using RTVue XR Avanti. To determine the condition of the posterior vitreous detachment (PVD) and the proliferative tissue of the NVD, we performed 12 mm horizontal and vertical scans through the disc using SS-OCT. RESULTS: OCT images of all 17 cases indicated there was no PVD on the optic disc. OCTA showed that the locations of the newly formed vessels from the optic disc were overwhelmingly outside the physiological cupping (95%). No cases exhibited formation of neovascularization inside the physiological cupping. OCT images revealed all 17 eyes had proliferative tissues located under the posterior wall of the vitreous, with 12 out of 17 eyes exhibiting additional invasion of the proliferative tissue into the vitreous through the posterior wall. Epiretinal membrane or a thickened posterior wall of the vitreous was present in 10 out of the 17 eyes. CONCLUSIONS: NVD associated with PDR arises from outside the physiological cupping and grows along the posterior wall of the vitreous. The absence of PVD on the optic disc is essential to the growth of NVD.

Evaluation of Fundus Blood Flow in Normal Individuals and Patients with Internal Carotid Artery Obstruction Using Laser Speckle Flowgraphy.

PURPOSE: We investigated whether laser speckle flowgraphy (LSFG) results are comparable in both eyes and whether it is useful in the diagnosis of disparity in ocular ischemic syndrome (OIS) patients. METHODS: We compared the mean blur rate (MBR) value for various fundus regions in both eyes of 41 healthy subjects and 15 internal carotid artery occlusion (ICAO) cases. We calculated the standard value of the Laterality Index (LI), which was the MBR comparison of both eyes in each of the regions, in the control subjects. We then investigated the correlation between both eyes for the LIs in the entire fundus, the degree of ICAO and visual function. RESULTS: The disparity of the LIs in both eyes was least in the entire area of the fundus in control subjects and there was a significant correlation between both eyes of the 41 healthy individuals (P = 0.019). Significant correlations were found for the LI, visual acuity and degree of ICAO. The specificity and sensitivity of LI in the entire area was 93.8% and 100%, respectively. CONCLUSIONS: LSFG revealed normal individuals have symmetrical fundus blood flow. LSFG could detect OIS and might be a useful tool for detecting disparities in fundus blood flow.

Different Filling Patterns of the Choriocapillaris in Fluorescein and Indocyanine Green Angiography in Primate Eyes Under Elevated Intraocular Pressure.

Purpose: To investigate the hemodynamics of the choriocapillaris in primate eyes under elevated intraocular pressure. Methods: Indocyanine green angiography (ICGA) and fluorescein angiography (FA) were performed in two monkeys after elevation of the intraocular pressure (IOP) to 35 and 60 mm Hg. Results: ICGA and FA showed no perfusion delays in the choriocapillaris at 35 mm Hg. The slow dye filling at 60 mm Hg made it possible to observe the early phase angiography sequence. During ICGA, C-shaped precapillary arterioles multiplied in numbers and emerged in the posterior pole, forming the outer rim of the numerous mosaics or lobules. Dye subsequently infiltrated into the lobules. During FA, after numerous hyperfluorescent spots emerged in the posterior pole, each of the spots enlarged and became numerous mosaics with a dark outer rim. When the FA and ICGA images were superimposed, the C-shaped arterioles observed during the ICGA were shown to correspond to the outer dark rim of the mosaics seen during the FA. The earliest dye emergence was delayed during FA compared to ICGA, with 13 seconds elapsing in monkey 1 and 4 seconds in monkey 2. The horizontal diameter of the optic disc contained three to four mosaics in both monkeys. Conclusions: The choriocapillaris lobules appear to be supplied from peripheral arterioles, not central. After blood perfuses the lobules, it drains into the venules at the center. Mosaic or lobular patterns during FA may reflect extravasated fluorescein from the fenestrated choriocapillaris.

Functional and morphologic consequences of light exposure in primate eyes.

PURPOSE: To evaluate the morphologic and functional changes of the primate retina after light exposure using spectral-domain optical coherence tomography (SD-OCT) and electroretinography (ERG). METHODS: Seven monkey eyes with light-emitting diode (LED) contact lenses were exposed to light for 8 hours. SD-OCT and ERG were performed bilaterally before, after the light exposure, and on days 1 and 14 in three monkeys. The tests were repeated after 4 months, followed by enucleation 12 hours later. Six eyes of three other animals were enucleated 12 hours after the first light exposure, and two eyes of one monkey were enucleated after 14 days, followed by microscopy. RESULTS: Immediately after light exposure, SD-OCT showed increased reflectivity of the outer segment (OS). Electron microscopy showed intracellular vacuolated and irregular lamellar structures at the proximal OS, while the distal end of the OS was unfolded at the RPE interface. At 14 days, the histologic changes and the OCT images returned to normal. ERG showed decreased cone and rod responses immediately after light exposure and decreased cone responses on day 1. Normalization occurred on day 14. CONCLUSIONS: Light exposure caused increased reflectivity of the photoreceptor OS, which corresponded to intracellular vacuolization and irregularity of the lamellar structure of the OS. OCT images returned to normal along with the histologic restoration. Rod and cone responses decreased transiently immediately after light exposure, which might be attributed to incomplete recovery from retinal bleaching.

Restoration of photoreceptor outer segment after vitrectomy for retinal detachment.

PURPOSE: To report photoreceptor restoration and visual outcomes after vitrectomy for retinal detachment. DESIGN: Retrospective, observational case series. METHODS: We prospectively studied the tomographic features of reattached retinas in 20 eyes with a macula-off rhegmatogenous retinal detachment using spectral-domain optical coherence tomography 1, 3, and 6 months after 3-port vitrectomy with SF(6) gas tamponade. All eyes were examined more than 3 months after surgery. RESULTS: The optical coherence tomography foveal findings were classified as a disrupted inner segment and outer segment (IS/OS) line, a residual foveal detachment, and a continuous IS/OS line. A disrupted IS/OS line was seen in 11 eyes (55%) at 1 month and in 8 eyes (40%) at 3 months, a foveal detachment was seen in 8 eyes (40%) at 1 month and in 7 eyes (35%) at 3 months, and a continuous IS/OS line was seen in 1 eye (5%) at 1 month and in 5 eyes (25%) at 3 months. In 18 eyes followed up for 6 months, optical coherence tomography showed a disrupted IS/OS line in 3 eyes (17%), a foveal detachment in 6 eyes (33%), and a continuous IS/OS line in 9 eyes (50%). The mean best-corrected visual acuities at 1 and 6 months were 0.26 and 0.16 with a disrupted IS/OS line, 0.60 and 0.95 with a foveal detachment, and 0.8 and 0.95 with a continuous IS/OS line. The mean best-corrected visual acuity was significantly (P < .0001) lower with a disrupted IS/OS line compared with the other formations at 6 months. CONCLUSIONS: The IS/OS line at the fovea recovered gradually after surgery. The postoperative visual acuity was correlated with a restored IS/OS line.

Restored photoreceptor outer segment and visual recovery after macular hole closure.

PURPOSE: To evaluate restoration of the photoreceptor outer segment and visual outcomes in closed macular holes. DESIGN: Retrospective case series. METHODS: We retrospectively observed the reparative process of macular holes in 28 eyes one, three, and six months postoperatively using spectral-domain optical coherence tomography. We evaluated the reflective line at the junction between the photoreceptor inner and outer segment (IS/OS) and the best-corrected visual acuity (BCVA). RESULTS: The outer photoreceptor layer showed a foveal detachment, a disrupted IS/OS line, or both one month postoperatively. No eye had a continuous IS/OS line. These abnormalities were gradually restored at various levels. At six months, nine eyes had a normal outer photoreceptor layer, four eyes outer foveal defects with a continuous IS/OS line, 12 eyes a disrupted IS/OS line, and three eyes outer foveal defects with a disrupted IS/OS line. The mean BCVAs were significantly (P = .017) lower in groups with a disrupted IS/OS line compared to groups with a continuous IS/OS line with or without outer foveal defects. CONCLUSIONS: Macular hole closure is attained by bridge formation (foveal detachment) and the IS/OS line heals in varying degrees. The visual outcomes were significantly better in eyes with a continuous IS/OS line than in those with a disrupted IS/OS line.

Effect of intravitreal injection of high-dose bevacizumab in monkey eyes.

PURPOSE: To evaluate the ocular complications of intravitreal injection of high dose bevacizumab in monkey eyes. METHODS: Four healthy monkeys (Macaca fuscata) received an intravitreal injection of either 6.25 or 12.5 mg bevacizumab in the right eye; the left control eye received an intravitreal injection of the same volume of saline. The eyes were examined using slit lamp and funduscopy, optical coherence tomography (OCT), electroretinography (ERG), fundus photography (FP), fluorescein angiography (FA), and indocyanine green angiography (ICGA). The eyes were enucleated 28 days after the intravitreal injection and subjected to light microscopy. RESULTS: No pathologic changes were observed by FP, FA, ICGA, OCT, and light microscopy in the eyes injected with either of the two bevacizumab doses. ERG showed no toxic change in the eyes that received the 6.25-mg dose. In two eyes that received the 12.5-mg dose, ERG showed no significant difference between the right and left eyes 4 weeks after injection, although there were transient changes in scotopic responses. CONCLUSIONS: No irreversible toxic effects were observed in monkey eyes receiving an intravitreal injection of high dose bevacizumab.

Effects of intraocular irrigation with melphalan on rabbit retinas during vitrectomy.

PURPOSE: To investigate the toxic effects of perfusion of intravitreal melphalan during vitrectomy on the rabbit retina. METHODS: We performed electoretinography (ERG) in 18 eyes of 18 healthy albino rabbits before and after intraocular melphalan perfusion at concentrations of 5-, 10-, and 20-microg/ml during pars plana vitrectomy. Fellow eyes that underwent vitrectomy without melphalan served as controls. The histopathologic retinal changes were observed in both eyes of two rabbits from each group. RESULTS: In the 5-microg/ml perfusion group, the ERGs and histology showed no substantial changes compared with control fellow eyes during 28 days postoperatively. In the 10- and 20-microg/ml groups, the mean a-wave amplitude decreased to 52% and 31% respectively of the fellow eye; the mean b-wave amplitude decreased to 52% and 19% respectively. However, the peak implicit time of the a- and b-waves did not significantly differ in the 10- and 20-microg/ml groups during 28 days postoperatively. Histologic sections showed necrosis of the inner nuclear layer and thinning of the outer nuclear layer in the 10-microg/ml group. Loss of the outer nuclear layer and the photoreceptor layer and necrosis of the inner nuclear layer were observed in the 20-microg/ml group. CONCLUSION: The intravitreal 5-microg/ml melphalan perfusion during vitrectomy appears to be nontoxic to the retina. This therapeutic modality might be a potential treatment for retinoblastoma with vitreous seeding.