[Show abstract][Hide abstract] ABSTRACT: Introduction
This study evaluated the usefulness of rigid endoscopy placed on the corneal surface to observe the peripheral retina.
The authors studied 15 eyes in 15 patients (12 men, 3 women; mean age 55.9 years; range 22–74 years) that underwent vitreous surgery at the Department of Ophthalmology at Saga University Hospital. With patients in a supine position, after topical anesthesia, an eye cup was placed between the eyelids and filled with hydroxyethyl cellulose solution and physiologic saline. With a rigid endoscope placed near the corneal surface, the target areas were then observed and recorded. The usefulness of rigid endoscopy to observe the peripheral retina was evaluated based on differences due to lens status and pupil size.
In seven aphakic eyes, irrespective of pupil size, the peripheral retina could be observed up to the entire ora serrata (all quadrants). In eight eyes implanted with an intraocular lens, the observable area changed with pupil size and anterior capsulorrhexis size.
This technique using rigid endoscopy was simple to manipulate and useful for observing and recording the peripheral retina. In particular, in aphakic eyes, irrespective of pupil size, the retina could be observed to the ora serrata.
[Show abstract][Hide abstract] ABSTRACT: Background:
To investigate the effect of using gelatin-microbial transglutaminase (gelatin-mTG) complex for treating experimental retinal detachment.
Vitrectomy with artificial posterior vitreous detachment (PVD) followed by induction of a retinal tear and detachment was performed in rabbit eyes. Gelatin-mTG complex or gelatin alone (control) was placed on the retinal tears. Fundus examination using optical coherence tomography (OCT) was performed after the surgery. Vitrectomy with PVD alone was also performed in additional rabbits. After application of the gelatin-mTG complex on the normal retinal surface, the electroretinogram (ERG) was measured 7 days after surgery.
Gelatin-mTG complex covered the retinal tear for more than 7 days after the vitrectomy, with less prominent inflammation. Reattachment of the retina occurred in all treated eyes. In contrast, massive fibrin materials were observed at 1 day after the surgery in the control group. In addition, OCT showed that all of the gelatin disappeared by day 3. Local retinal detachment remained in three of the eyes. As demonstrated by the ERG, gelatin-mTG complex had no harmful effects on retinal function.
The results indicate that gelatin-mTG complex continues to adhere and seal retinal tears for at least several days after administration without any inflammatory reaction.
No preview · Article · Jan 2013 · Albrecht von Graæes Archiv für Ophthalmologie
[Show abstract][Hide abstract] ABSTRACT: To investigate neuroprotective effects of siRNA targeted to caspase-3 against ischemia and reperfusion (I/R) injury in rat eyes.
Retinal ischemia was induced in Wistar rats by increasing the intraocular pressure (IOP) to 110 mmHg for 120 min. To examine the effect of siRNA on rat caspase-3, siRNA was injected into the vitreous cavity 24 h prior to induction of retinal ischemia. Eyes were removed at 2, 7 or 14 days later, and then analyzed for the number of retinal ganglion cells (RGCs), the retinal thickness and the amount of apoptosis of the retinal neural cells (as demonstrated by the TUNEL assay). The amount of caspase-3 mRNA was analyzed by rt-PCR. Differences between groups were evaluated by an unpaired t test.
The numbers of RGCs in the saline and non-silencing siRNA controls were reduced significantly at 2 and 7 days after the I/R injury. RGCs were significantly retained in eyes pretreated with siRNA targeted to caspase-3 as compared to the control eyes at 2 days after the I/R injury. Inner retinal thickness in the control eyes was significantly thinner as compared to the treated eyes at 2 and 7 days after the I/R injury. After siRNA treatment, the amount of caspase-3 mRNA was significantly lower when compared to the saline control group.
The injection of siRNA targeted to caspase-3 into the vitreous cavity of rat eyes may block caspase-3, and may thus be able to prevent retinal cell death associated with ischemic injury. As inhibition of the apoptosis pathway may provide a neuroprotective effect, examination of new strategies for treating these disorders needs to be undertaken.
No preview · Article · May 2012 · Current eye research
[Show abstract][Hide abstract] ABSTRACT: To examine the effects of anti-VEGF antibody (bevacizumab) on the number of fenestrations in rat choriocapillaris.
Twenty-four eyes from 24 male Wister rats were injected intravitreally with 0.125 mg of bevacizumab. The rats were perfusion fixated at 1, 3, 7, 14 or 28 days after injection. The surfaces of the choriocapillaris on the RPE side were observed using scanning electron microscopy. Four eyes treated with human IgG were used as controls. The area sieve plate and the number of fenestrations after the bevacizumab injection were measured and compared with controls.
In the controls, the sieve plate area was 80.7% of the total choriocapillaris area. The number of fenestrations was 69.2 +/- 0.2 /microm(2) of the fenestrated area. While there were no changes in the fenestrated area for any of the time points after the bevacizumab treatment, the number of fenestrations was significantly reduced to 52.9 +/- 4.4 at day 1, 55.6 +/- 3.6 at day 3 and 53.6 +/- 8.6 /microm(2) of the luminal surface at day 7 (ANOVA, p < 0.05).
In this study, intravitreal bevacizumab injection reduced fenestration of the normal choriocapillaris. These results indicate there is a latent risk inherent with bevacizumab treatment of normal choriocapillaris.
No preview · Article · Feb 2009 · Albrecht von Graæes Archiv für Ophthalmologie