Hirotaka Itakura

Observation of Posterior Precortical Vitreous Pocket Using Swept-Source Optical Coherence Tomography

PURPOSE To observe posterior precortical vitreous pockets (PPVPs) using swept-source optical coherence tomography (SS-OCT). METHODS We performed SS-OCT in both eyes of 58 volunteers (36 men, 22 women) using 12-mm horizontal vertical scans through the macula and optic disc. To minimize age-related changes (liquefaction or posterior vitreous detachment), all subjects were a mean of 26.2 years (range, 22-40 years). The refractive errors ranged from -9.5 diopters (D) to +3.0 D. To estimate the PPVP size, we measured the height between the fovea and the anterior border of the PPVP and the maximal width in the 12-mm horizontal scan through the fovea and disc. RESULTS SS-OCT visualized the PPVPs as boat-shaped lacunae in the macular area bilaterally in all subjects (maximal width, 3114-9887 μm; mean width, 6420.6; central height, 208-1877 μm; mean height, 708.1 in the right eyes, with no significant difference in the left eyes). There was a significant correlation between the PPVP height and myopic refractive error. The posterior wall of the PPVP was a thin vitreous cortex, thinnest at the fovea. The septum was between the nasal border of the pocket and Cloquets canal, which extended forward and tilted superiorly in all cases. A channel connected Cloquets canal and the PPVPs bilaterally in 54 (93.1%) of 58 cases. CONCLUSIONS SS-OCT clarified the boat-shaped PPVP structure in vivo. Although the central height increased with the myopic refractive error, the width was unchanged. A channel connecting Cloquets canal and PPVP suggested the route of aqueous humor into the PPVP.

Aging changes of vitreomacular interface.

Purpose: The posterior precortical vitreous pocket (the pocket) is a premacular liquefied lacuna, the physiologic presence of which was reported in autopsy eyes. We describe the morphologic features of the pocket in normal individuals. Methods: We performed spectral-domain optical coherence tomography in 102 eyes of 51 normal subjects of various ages in a sitting position. Results: The pocket was identified as an optically lucent space anterior to the posterior fundus in 85 of 102 eyes (83.3%) in the age-group. The vitreous cortex was extremely thin at the central fovea, and it gradually thickened along with age in the perifoveal area. A shallow perifoveal posterior vitreous detachment developed in 16 of 32 eyes (50%) of subjects aged >51 years. The lamellar structure of the vitreous cortex was seen in 7 of the 32 eyes (22%) of subjects aged >51 years. Conclusion: Spectral-domain optical coherence tomography confirmed the presence of the pocket in all ages. Thickened vitreous cortex and perifoveal posterior vitreous detachment were physiologic findings in older individuals. The lamellar structure of the vitreous cortex may be related to the vitreoschisis.

Evolution of Vitreomacular Detachment in Healthy Subjects

IMPORTANCE Development of posterior vitreous detachment (PVD) plays an important role in vitreomacular diseases. Spectral-domain optical coherence tomography (SD-OCT) with noise reduction can visualize a posterior precortical vitreous pocket (PPVP) and classify PVD stages according to the state of the posterior wall of the PPVP. OBJECTIVE To describe the role of the PPVP in early-stage PVDs in healthy individuals. DESIGN, SETTING, AND PARTICIPANTS We performed biomicroscopy and SD-OCT in the right eyes of 368 healthy volunteers (188 males and 180 females; mean [SD] age, 57.1 [19.4] years; range, 12-89 years). RESULTS The condition of the posterior wall of the PPVP was classified into stages according to the biomicroscopic findings and SD-OCT images: stage 0, no PVD with PPVP (134 eyes; mean [SD] subject age, 38.7 [16.5] years; range, 12-76 years); stage 1, paramacular PVD with PPVP (47 eyes; mean age, 55.2 [10.3] years; range, 36-77 years); stage 2, perifoveal PVD with PPVP (27 eyes; mean age, 62.0 [8.7] years; range, 46-81 years); stage 3, vitreofoveal separation with persistent attachment to the optic disc (19 eyes; mean age, 65.8 [6.2] years; range, 55-80 years; stage 3a, vitreofoveal separation with an intact posterior wall of the PPVP in 12 eyes; stage 3b, vitreofoveal separation with a defect in the posterior wall of the PPVP in 7 eyes; and stage 4, complete PVD (141 eyes; mean age, 73.2 [8.3] years; range, 48-89 years). MAIN OUTCOMES AND MEASURES Ages in each PVD stage. CONCLUSIONS AND RELEVANCE The posterior wall of the PPVP initially detaches at the paramacular area and extends to the perifoveal area, which results in a perifoveal PVD. A vitreofoveal detachment may develop with or without a defect in the PPVP. When the vitreous detaches from the optic disc, a complete PVD develops. An anatomical feature of the PPVP may play a role in the development of a perifoveal PVD.

Vitreous Changes in High Myopia Observed by Swept-Source Optical Coherence Tomography

PURPOSE To observe vitreous changes in high myopia using swept-source optical coherence tomography (SS-OCT). METHODS We performed slit-lamp biomicroscopy and SS-OCT in the highly myopic right eyes of 151 patients (mean age, 52.7 years; mean refraction, -11.4 diopters [D]) and the right eyes with no myopia of 363 healthy control volunteers (mean age, 52.8 years; mean refraction, -1.4 D). To estimate the sizes of the posterior precortical vitreous pockets (PPVPs), we measured the height between the fovea and the anterior border of the PPVPs. RESULTS Patients with partial posterior vitreous detachments (PVDs) around the macula and complete PVDs in high myopia were significantly (P < 0.0001) younger (47.1 ± 14.1 and 61.2 ± 12.0 years, respectively) than controls (59.0 ± 9.6 and 69.7 ± 6.6 years). The PPVPs with no PVDs were significantly (P < 0.001) higher in 32 eyes with high myopia (984 ± 292 μm) than 164 controls (553 ± 166 μm). After a complete PVD with a Weiss ring developed, the vitreous cortex was on the macula in 40.5% of the eyes with high myopia, which differed significantly (P < 0.0001) from the 8.7% of the controls. Myopic foveoschisis was present in 14 (9.3%) of 151 eyes. In eyes with foveoschisis, three (21.4%) eyes had partial PVDs and 11 (78.6%) eyes had complete PVDs; there was no residual cortex in 8 (72.7%) of 11 eyes with complete PVDs. CONCLUSIONS Highly myopic eyes may have larger PPVPs than normal eyes. Partial PVDs around the macula and complete PVDs occur at younger ages. The vitreous cortex more frequently remains on the macula after development of complete PVDs in highly myopic eyes.

Rebamipide ophthalmic suspension for the treatment of dry eye syndrome: a critical appraisal

Rebamipide was initially developed and approved for use in treating gastric ulcers and lesions associated with gastritis. Discovery of its ability to increase gastric mucin led to investigations of its effect on ocular surface mucin and the subsequent development for use in dry eye patients. Investigations have confirmed that rebamipide increases corneal and conjunctival mucin-like substances along with improving corneal and conjunctival injury. Clinically, rebamipide ophthalmic suspensions can effectively treat tear deficiency and mucin-caused corneal epithelial damage, and can restore the microstructure responsible for tear stability. Topical rebamipide has also been shown to be effective in treating other ocular surface disorders such as lagophthalmos, lid wiper epitheliopathy, and persistent corneal erosion. Rebamipide’s ability to modify epithelial cell function, improve tear stability, and suppress inflammation in the absence of any known major side effects suggest that it may be a beneficial first drug of choice for severe dry eye treatment and other ocular surface disorders. This review summarizes the history and development of this innovative dry eye treatment from its initial use as an effective stomach medication to its current use in the treatment of dry eye in Japan.

Alterations of posterior precortical vitreous pockets with positional changes.

Purpose: To investigate the morphologic features of posterior precortical vitreous pockets (PPVPs) with positional changes using spectral domain optical coherence tomography. Methods: The authors measured the distance between the fovea and anterior PPVP border on spectral domain optical coherence tomography scans in both eyes of 20 consecutive individuals and compared the differences with changes in position from sitting to supine. Results: A PPVP was identified in both eyes of 14 individuals (70%). In the vertical scan, the superior portion of the pocket was larger than the inferior portion in all 28 eyes when the participants were sitting. The mean distances between the fovea and the anterior PPVPs that border in the right and left eyes, respectively, were 477.6 ± 40.7 &mgr;m and 497.1 ± 31.8 &mgr;m when the participants were sitting and 665.6 ± 51.6 &mgr;m and 750.5 ± 48.2 &mgr;m when the participants were supine. The differences between the 2 positions were significant (P < 0.005). Conclusion: The superior portion of the PPVPs enlarged when the participants were sitting. The anterior border of the pocket moved anteriorly when the participants were supine.

Decreased Vitreal Hyaluronan Levels with Aging

Purpose: To investigate age-related changes in hyaluronan levels in human eyes before and after vitrectomy surgery, we measured the hyaluronan levels in the vitreous samples obtained during vitrectomy and postoperative fluid-air exchange. Methods: We obtained the vitreous during vitrectomy from 26 eyes of 26 patients with macular hole (MH) and 52 eyes of 52 patients with diabetic retinopathy (DR). After vitrectomy, we collected fluid samples during fluid-air exchange from 6 eyes with MH and 9 eyes with DR. The hyaluronan level was measured by the sandwich binding protein assay. Results: In the vitreous of the 54 eyes (26 eyes with MH and 28 eyes with DR and no vitreous hemorrhage), hyaluronan levels significantly decreased with patient age (r = –0.66, p < 0.00000005). Hyaluronan levels in postoperative vitreous fluid were significantly lower in 6 eyes with MH (p < 0.05) and 9 eyes with DR (p < 0.01) than those obtained during vitrectomy. Conclusions: There was a significant decrease in vitreous hyaluronan with aging. High-molecular-weight hyaluronan appears not to be formed in vitreous fluid after vitrectomy.

Topical rebamipide improves lid wiper epitheliopathy

Administration of topical rebamipide increases the mucin level of tear film and improves the ocular surface in short break-up time type of dry eye. Lid wiper epitheliopathy (LWE) is a disorder of the marginal conjunctiva of the upper eyelid with dry eye symptoms. LWE may be related to mechanical forces during blinking resulting in inflammation of the ocular surface. Rebamipide also has various anti-inflammatory effects. In this report, we tried treatment with topical rebamipide for two cases of LWE. One case had been treated with sodium hyaluronate ophthalmic solution and diquafosol sodium eye drops by other doctors for several weeks. The other case was not previously treated. In both cases, fluorescein staining of the cornea and lid margin was remarkably improved, ocular symptoms decreased, and tear film break-up times increased with rebamipide eye drops four times daily for 2-3 weeks. Topical rebamipide was effective for corneal and conjunctival disorders in LWE. This drug may provide a novel approach to the treatment of LWE.

En Face Imaging of Posterior Precortical Vitreous Pockets Using Swept-Source Optical Coherence Tomography

PURPOSE To obtain sequential flat (en face) images of posterior precortical vitreous pockets (PPVPs) using swept-source optical coherence tomography (SS-OCT). METHODS We performed SS-OCT in the right eyes of 112 volunteers (mean age, 30.1 years; mean refraction, -2.5 diopters) while sitting using 12-mm horizontal, vertical scans of the 12- × 9-mm plane × 2.6-mm depth through the macula and optic disc. En face images of the posterior vitreous were obtained by En-View, a SS-OCT program. RESULTS Swept-source OCT visualized the PPVPs and Cloquets canals in all subjects; the PPVPs appeared as boat-shaped lacunae in the horizontal scan and extended superiorly as clefts in the vertical scan. En face imaging showed PPVPs and Cloquets canals as two oval lacunae near the vitreoretinal interface and a septum between the nasal border of the PPVPs and Cloquets canals. In all cases, the lacunas of the PPVPs were larger than those of Cloquets canals. In 99 (88.4%) of 112 eyes, the PPVPs and Cloquets canals were fused by connecting channels. The mean width of the connecting channels was 920.2 ± 37.4 μm, and the mean height was 288.6 ± 20.0 μm. On the anterior en face images, the PPVPs became crescent-shaped in all eyes. CONCLUSIONS Using SS-OCT, we obtained en face images of PPVPs and Cloquets canals in vivo. The en face images of the PPVPs near the retina showed oval shapes that changed to crescents, which corresponded to the superior edge of the PPVPs. The PPVPs were fused with Cloquets canal by a flat-shaped connecting channel.

Restored Photoreceptor Outer Segment in Commotio Retinae

BACKGROUND AND OBJECTIVE The patient characteristics, risk factors, and outcome of penetrating keratoplasty (PK) wound dehiscence following late suture removal. PATIENTS AND METHODS Retrospective review of 207 cases of PK performed between 2005 and 2007 in Beilinson Hospital, Israel. RESULTS Analysis of 207 patients who underwent PK revealed 4 cases (an incidence of 1.93%) that developed spontaneous wound dehiscence with severe endophthalmitis following late suture removal. Mean time from transplantation to suture removal was 22.18 months (range: 18 to 26 months). The time from suture removal to endophthalmitis was on average 2.25 weeks. All patients underwent vitrectomy with injection of intraocular antibiotics. The causative microorganism was found to be Streptococcus species in three patients and Staphylococcus epidermidis in one patient. One patient retained a clear corneal graft, another patient is scheduled for repeat PK, and the last two patients lost sight (50%). CONCLUSION Endophthalmitis and wound dehiscence following late suture removal after PK are rare complications, but the end result can be devastating to the transplanted eye when they do occur. Careful monitoring and close follow-up can aid in early identification and treatment of such complications and may prevent loss of sight. Newer methods of corneal transplantation, such as Descemets stripping automated endothelial keratoplasty or Descemets membrane endothelial keratoplasty, should be considered as a better alternative to PK whenever the case qualifies as such.