Effect of Ca(2+)-free and Mg(2+)-free BSS Plus solution on the retinal pigment epithelium and retina in rabbits

PURPOSE

To determine whether intravitreal irrigation with Ca(2+)-free and Mg(2+)-free BSS Plus (Alcon Laboratory, Fort Worth, Texas) solution alters the adhesiveness between the retinal pigment epithelium and the retina of rabbits.

METHODS

Thirty-four eyes of 34 Dutch pigmented rabbits underwent lensectomy and vitrectomy. Subsequently, the vitreous cavity of 24 eyes was irrigated with Ca(2+)-free and Mg(2+)-free BSS Plus solution for 10 or 20 minutes. The other 10 eyes were irrigated with BSS Plus solution for 20 minutes as controls. To determine the adhesiveness between the retinal pigment epithelium and retina, a retinal detachment was produced in 12 of the 34 eyes. The apical surface of the retinal pigment epithelium and the photoreceptor outer segments were examined by scanning electron microscopy. Retinal physiology was assessed by electroretinography and retinal morphology by light microscopy.

RESULTS

After retinal detachment was produced, the number of cone sheaths on the apical surface of the retinal pigment epithelium after irrigation with Ca(2+)-free and Mg(2+)-free BSS Plus solution for 20 minutes (33 +/- 15, mean +/- SD) was significantly less than the number of cone sheaths on the apical surface of the retinal pigment epithelium of eyes after irrigation with BSS Plus solution for 20 minutes (120 +/- 50) or the number of cone sheaths on the apical surface of the retinal pigment epithelium of eyes after 10 minutes of irrigation with Ca(2+)-free and Mg(2+)-free BSS Plus solution (115 +/- 49; P =.02). The b-wave amplitudes in the eyes irrigated with Ca(2+)-free and Mg(2+)-free BSS Plus solution for 20 minutes were depressed compared with the b-waves in eyes irrigated with BSS Plus solution for 20 minutes on the first postoperative day (P =.03). After the third postoperative day, there was no significant difference in the b-waves (P >.06). Light microscopy demonstrated no morphologic abnormalities after the use of both solutions.

CONCLUSIONS

Intravitreal irrigation with Ca(2+)-free and Mg(2+)-free BSS Plus solution for 20 minutes altered the adhesion between the retinal pigment epithelium microvilli and retinal outer segments and made the creation of retinal detachment less traumatic. These results suggest that Ca(2+)-free and Mg(2+)-free BSS Plus solution may be of clinical value for the creation of an intentional retinal detachment for foveal translocation surgery.

[Epithelial scraping for corneal epithelial ingrowth after laser in situ keratomileusis]

BACKGROUND

Laser in situ keratomileusis (LASIK) is an effective method for correcting a wide range of myopia. However, complications sometimes occur. We report here a case treated with epithelial scraping two years and 4 months after surgery for epithelial ingrowth in the central cornea after LASIK.

CASE

A 32 year-old woman who had undergone LASIK one year and 4 months before visited our hospital because of visual loss. At the first examination in our clinic, her best-corrected visual acuity was 20/60 in the right eye and 20/15 in the left eye. Epithelial ingrowth was observed in both eyes, but in the right eye, the epithelial ingrowth had reached the central cornea leading to the visual loss. The increased corneal stromal opacity decreased the visual acuity to 20/400. The patient decided to undergo epithelial scraping. The corneal flap was dissected again and epithelial scraping was performed on the stromal bed and back of the corneal flap. The visual acuity was improved from 20/400 to 20/40. However, the stromal opacity and the corneal astigmatism still remained.

CONCLUSION

This case suggests that epithelial scraping should be performed immediately when ingrowing epithelium after LASIK begins to invade the central cornea.

Epithelial pigment slide in contact lens wearers: a possible marker for contact lens-associated stress on corneal epithelium

PURPOSE

To compare the incidence of epithelial pigment slide among wearers of various types of contact lenses.

METHODS

Prospectively, we studied 432 eyes of 432 patients. The patients were separated into 6 groups: hard contact lens (HCL) wearers (n = 166), conventional soft contact lens (CSCL) wearers (n = 30), extended disposable lens (EDCL) wearers (n = 46), frequent replacement SCL (FRCL) wearers (n = 60), daily disposable SCL (DDCL) wearers (n = 65), and normal controls (n = 65). The incidence of prominent pigment slide, defined as spike-like epithelial opacities in the corneal limbus and longer than 1 mm from the base to the apex of the wedges-shaped process detected by slit-lamp examination, was compared in these 6 groups. The relationship between the incidence of prominent pigment slide and the length of contact lens wear was examined.

RESULTS

The overall incidence of prominent pigment slide in the CSCL, EDCL, HCL, FRCL, DDCL, and normal groups was 63.3, 23.9, 13.9, 8.3, 7.7, and 4.6%, respectively. The incidence of prominent pigment slide in the CSCL and EDCL groups was significantly higher than that in the control group. A higher incidence of prominent pigment slide was correlated with longer wearing period in each group.

CONCLUSIONS

The presence of epithelial pigment slide may be a marker for contact lens-associated stress to the corneal epithelium.

Effect of a nitric oxide synthase inhibitor on lens-induced myopia

PURPOSE

It has still not been determined whether the retinal mechanism causing form-deprivation myopia (FDM) is different from that causing lens-induced myopia (LIM). We previously reported that FDM was blocked by an intravitreal injection of the nitric oxide (NO) synthase inhibitor, N-nitro-L-arginine methyl ester (L-NAME). In this study, we investigated the effect of L-NAME on LIM in chicks.

METHOD

The left eyes of 6-day-old chicks were injected with 30 microl of nontoxic concentrations of L-NAME (< or = 360 mM) or saline. The right eyes were injected with 30 microl of saline. A -16 dpt lens was placed in front of the left eye for 6 days. Another group of 6 chicks were injected with 180 mM L-NAME (left eye) and with saline (right eye) before placing -16 dpt lenses in front of both eyes. After removing the lens, the refraction and the axial length were measured. The effect of L-NAME (180 mM) on the retina of a separate group of chicks was examined by electroretinography 60 min after an intravitreal injection in non-LIM-treated eyes.

RESULTS

The eyes of chicks that were injected with 180 or 360 mM L-NAME were less myopic and had significantly shorter axial lengths than control eyes. A significant decrease of the On response and an increase of the Off response were observed.

CONCLUSION

The injection of L-NAME into developing chick eyes that were then covered with a -16 dpt lens resulted in a modifications of retinal function and an inhibition of the development of myopia. These results, combined with the earlier findings, suggest that NO modulates a common retinal pathway that leads to both LIM and FDM.

Magnifying prismatic lenses for vitrectomy

PURPOSE

Viewing the fundus at higher magnification during vitrectomy makes surgical procedures much safer; however, the scope of magnification of the peripheral fundus has been limited. For better visualization of the periphery of the fundus, we have developed two new contact lenses called magnifying prismatic lenses.

METHODS

The magnifying 15 degrees and 30 degrees prismatic lenses are made of a glass with a high index of refraction (n = 1.883). The lenses have a convex upper surface to provide a magnified view of the peripheral fundus.

RESULTS

These magnifying 15 degrees and 30 degrees prismatic lenses provide an approximately 2x magnified view of the peripheral fundus. They also provide a more extensive view of the peripheral fundus than a regular (plano-concave) prismatic lens when the eye is tilted.

CONCLUSION

The magnifying prismatic lenses are useful for viewing into the peripheral fundus with higher magnification.

Indocyanine green facilitates removal of epiretinal and internal limiting membranes in myopic eyes with retinal detachment

PURPOSE

To describe the use of intravitreal indocyanine green as an aid to identifying epiretinal membranes and internal-limiting membranes during surgery for a retinal detachment resulting from a macular hole.

METHODS

A 62-year-old man who had a retinal detachment resulting from a macular hole underwent vitrectomy. During the surgery, intravitreal indocyanine green was injected intravitreally.

RESULTS

The internal-limiting membrane was stained green, but the epiretinal membrane was unstained. Because the epiretinal membrane and internal-limiting membrane were clearly identified, they could be completely removed. The clinical observations of the epiretinal membrane and internal-limiting membrane excised were confirmed by electron microscopy. Successful reattachment was obtained without damage to the retina.

CONCLUSION

Removal of epiretinal membrane and internal-limiting membrane can be facilitated by using intravitreal indocyanine green during vitrectomy. We recommend further studies to confirm the benefit of this technique.

Functional Kir7.1 channels localized at the root of apical processes in rat retinal pigment epithelium

1. The inwardly rectifying K+ channel current (IK(IR)) recorded from isolated retinal pigmented epithelial (RPE) cells showed poor dependence on external K+ ([K+]o) and low sensitivity to block by Ba2+. We examined the molecular identity and specific subcellular localization of the KIR channel in RPE cells. 2. The Kir7.1 channel current heterologously expressed in HEK293T cells (human embryonic kidney cell line) showed identical properties to those of the RPE IK(IR), i.e. poor dependence on [K+]o and low sensitivity to Ba2+ block. 3. Expression of Kir7.1 mRNA and protein was detected in RPE cells by RT-PCR and immunoblot techniques, respectively. 4. Immunohistochemical studies including electron microscopy revealed that the Kir7.1 channel was localized specifically at the proximal roots of the apical processes of RPE cells, where Na+,K+-ATPase immunoreactivity was also detected. 5. The middle-distal portions of apical processes of RPE cells in the intact tissue exhibited immunoreactivity of Kir4.1, a common KIR channel. In the isolated RPE cells, however, Kir4.1 immunoreactivity was largely lost, while Kir7.1 immunoreactivity remained. 6. These data indicate that the only IK(IR) recorded in isolated RPE cells is derived from the functional Kir7.1 channel localized at the root of apical processes. Co-localization with Na+,K+-ATPase suggests that the Kir7.1 channel may provide the pathway for recycling of K+ to maintain pump activity and thus is essential for K+ handling in RPE cells.

Histology of microcornea complicated by bullous keratopathy

PURPOSE

To report a child with a microcornea complicated by bullous keratopathy and to present the results of a developmental and histological investigation of a microcornea.

METHODS

Clinical and histopathological examination.

RESULTS

Histopathological examination of the microcornea showed that the microcornea of our case lacked the non-banded zone of Descemet's layer and formed collagenous layer and secondary Descemet's membrane.

CONCLUSION

This case demonstrates that histological finding of microcornea is not necessarily normal.

Macular translocation: unifying concepts, terminology, and classification

PURPOSE

To describe some unifying concepts, terminology, and classification of macular translocation so as to facilitate communication within the scientific community.

METHODS

A panel of ophthalmologists with expertise in macular translocation reviewed available data and developed some unifying concepts, terminology, and classification of macular translocation.

RESULTS

Macular translocation may be defined as any surgery that has a primary goal of relocating the central neurosensory retina or fovea intraoperatively or postoperatively specifically for the management of macular disease. It may be classified according to the size of the retinotomy and, where applicable, the technique of chorioscleral shortening used. The direction of macular translocation is denoted by the movement of the neurosensory macula relative to the underlying tissues. Effective macular translocation may be defined as successful intraoperative or postoperative relocation of the fovea overlying a subfoveal lesion to an area outside the border of the lesion. The concepts of minimum desired translocation and median postoperative foveal displacement can give some useful idea of the likelihood of effective macular translocation before surgery.

CONCLUSIONS

Use of a common standardized terminology for macular translocation will facilitate communication within the scientific community and enhance further research in this area. However, the definitions, terms, classification, and concepts concerning macular translocation are likely to continue to evolve as macular translocation undergoes further modifications and refinements.

Nestin-EGFP transgenic mice: visualization of the self-renewal and multipotency of CNS stem cells

We generated transgenic mice carrying enhanced green fluorescent protein (EGFP) under the control of the nestin second-intronic enhancer (E/nestin:EGFP). Flow cytometry followed by in vitro assays revealed that in situ EGFP expression in the embryonic brain correlated with the mitotic index, the cogeneration of both neurons and glia, and the frequency of neurosphere formation in vitro. High-level EGFP expressors derived from embryos included a distinct subpopulation of cells that were self-renewable and multipotent, criteria that define neural stem cells (NSCs). Such cells were largely absent among lower-level or non-EGFP expressors, thereby permitting us to enrich for NSCs using EGFP expression level. In adults, although E/nestin:EGFP-positive cells included the NSC population, the frequency of neurosphere formation did not correlate directly with the level of EGFP expression. However, moderately EGFP-expressing cells in adults gained EGFP intensity when they formed neurospheres, suggesting embryonic and adult NSCs exist in different microenvironments in vivo.

Emulsification tendency of silicone-phenylsilicone copolymer

PURPOSE

We compared the emulsification tendency of silicone-phenylsilicone copolymer (DPC; 5%-phenylated, specific gravity 0.984) with that of silicone oil (SO; specific gravity 0.966) and fluorosilicone oil (FSO; specific gravity 1.256), all of which are used clinically as intraocular tamponades.

METHODS

We investigated the tendencies of emulsification in SO, FSO, and DPC. Each was placed in a separate glass container with equal amounts of albumin solution (1 mg/mL) or 1 gamma-globulin solution (1 mg/mL) and shaken. We also investigated the toxicity of DPC in the rabbit eye. Following vitrectomy, we injected DPC into the vitreous cavity and assessed the retinal damage histologically.

RESULTS

The SO and DPC, because their specific gravities, are closer to water, tended to become less emulsified than did FSO. We found that DPC did not cause any severe histological damage in the rabbit retina.

CONCLUSION

Highly phenylated DPC is slightly heavier than water and may be used instead of FSO to treat inferior retinal detachment.

Visual function after foveal translocation with 360-degree retinotomy and simultaneous torsional muscle surgery in patients with myopic neovascular maculopathy

PURPOSE

To assess functional and anatomical outcomes after foveal translocation with 360-degree retinotomy and simultaneous torsional muscle surgery in patients with myopic neovascular maculopathy.

METHODS

Foveal translocation with 360-degree retinotomy was performed in 11 eyes of 11 patients with myopic neovascular maculopathy. Ten eyes had simultaneous torsional muscle surgery with recession of the superior oblique muscle and tucking of the inferior oblique muscle. Silicone oil removal with or without intraocular lens implantation was performed 2 to 8 weeks after the primary procedure. Visual acuity, binocular function, and degree of cyclotorsion were assessed preoperatively and postoperatively. Angles of retinal and globe rotation, distance of foveal shift, and surgical complications were also investigated.

RESULTS

With a mean postoperative follow-up of 6.2 months (range, 3 to 13 months), vision improved (greater than 0.2 logarithm of minimal angle of resolution [logMAR] units) in eight eyes, was unchanged in two eyes, and worsened (greater than 0.2 logMAR units) in 1 eye. Seven of 11 eyes (64%) had a final visual acuity of 20/50 or better. Five patients developed or maintained binocular fusion, four patients continued to have suppression, and two patients developed diplopia that was managed by spectacles with Fresnel prisms. Subjective cyclotorsion was less than 8 degrees in 10 eyes. Mean retinal and globe rotations were 23.4 degrees and 19.8 degrees, respectively. Average size of the choroidal neovascular membrane was 0.8 disk diameter, whereas the average distance of foveal shift was 1.5 disk diameter. After the primary procedure, three eyes developed retinal detachment, one eye macular hole, and one eye proliferative vitreoretinopathy. These complications were successfully managed by additional surgery.

CONCLUSION

Foveal translocation with 360-degree retinotomy is effective in restoring vision in some patients with myopic neovascular maculopathy. Although the development of torsional diplopia is generally obviated by simultaneous extraocular muscle surgery, a relatively high incidence of surgical complications should be taken into account with this procedure.

Preventive effect of local plasmid DNA vaccine encoding gD or gD-IL-2 on herpetic keratitis

PURPOSE

The goal of this study was to evaluate the effectiveness of a local plasmid DNA vaccine encoding herpes simplex virus (HSV) type 1 glycoprotein D (gD) or gD-interleukin (IL)-2 (chimeric gene of gD and human IL-2) in preventing murine herpetic keratitis.

METHODS

Plasmids containing gD (pHSDneo1), gD-IL-2 (pHDLneo1), or vaccine vector (pHSGneo) were injected subconjunctivally with BALB/c mice on days 0 and 7 (90 microgram x 2). Immunization was indicated by positive virus-neutralizing antibody titer, swollen pinna (due to delayed-type hypersensitivity [DTH] reaction), and release of (51)Cr from splenic and/or local cytotoxic effector cells on day 28. In another group of the immunized mice, corneas were challenged with HSV-1 (CHR3 strain, 10 microliter of 3 x 10(6) plaque-forming units [PFU]/ml). Mice were evaluated for clinical signs of epithelial or stromal keratitis on days 1 through 8 and days 10 and 14 or measured on days 2, 4, or 6 for viral titers in the eyes, trigeminal ganglia, and brain.

RESULTS

All gD-DNA-injected mice obtained specific immunity. Furthermore, gD-IL-2-DNA elicited a higher DTH reaction and more vigorous cytotoxic effector cell activity. Stromal keratitis scores were lower for all immunized mice compared with control mice, although the difference in epithelial keratitis scores was not statistically significant. Viral titers in eyes, trigeminal ganglia, and brains were suppressed in all immunized mice.

CONCLUSIONS

Local immunization with plasmid DNA encoding gD or gD-IL-2 induces humoral and cellular immunity against HSV-1 and inhibits development of stromal keratitis. gD-IL-2 DNA induces greater cell-mediated immunity than gD DNA alone. A plasmid encoding gD-IL-2 is therefore a promising candidate for a vaccine against HSV-1.

Retinal changes after retinal translocation surgery with scleral imbrication in dog eyes

PURPOSE

To examine retinal changes induced by scleral imbrication during retinal translocation surgery in dog eyes.

METHODS

Fifteen dogs were anesthetized and underwent retinal translocation surgery. After lensectomy and vitrectomy, an intentional retinal detachment was created, and the upper temporal sclera around the equator was imbricated with five mattress sutures. Translocated distances were calculated by pre- and postoperative photographs. At 1, 2, and 4 weeks after the surgery, the retina was studied by TdT-dNTP terminal nick-end labeling (TUNEL) and immunohistochemistry of peanut agglutinin (PNA) lectin and glial fibrillary acidic protein (GFAP).

RESULTS

The retina was translocated by a mean distance of 0.53 +/- 0.30 disc diameters or 959 +/- 543 micrometer. Retinal folds were created around the optic disc in all eyes. Histologic examination of the retinal folds 1 week after the surgery showed many TUNEL-positive cells in the outer nuclear layer, loss of photoreceptor cells, and shortening of the outer and inner segments. A strong immunoreactivity to GFAP was detected in the folds of the retina.

CONCLUSIONS

. The results demonstrated that retinal translocation surgery by scleral imbrication inevitably caused retinal folds as a postoperative complication, and the retina within the folds showed extensive loss of photoreceptor cells. It is recommended that the foveal translocation surgery be planned to avoid involving the fovea in the retinal folds.

Inhibition of experimental choroidal neovascularization by overexpression of tissue inhibitor of metalloproteinases-3 in retinal pigment epithelium cells

PURPOSE

To evaluate the feasibility of introducing exogenous tissue inhibitor of metalloproteinases-3 gene into the rat retinal pigment epithelium using hemagglutinating virus of Japan liposomes and to assess the effect of tissue inhibitor of metalloproteinases-3 overexpression in retinal pigment epithelium cells on the formation of experimental choroidal neovascularization.

METHODS

Hemagglutinating virus of Japan liposomes containing hemagglutin epitope-tagged tissue inhibitor of metalloproteinases-3 gene were injected into the subretinal space in rat eyes. Localization of oligonucleotides was evaluated by fluorescence microscopy. Exogenous tissue inhibitor of metalloproteinases-3 mRNA expression was assessed by reverse transcribed polymerase chain reaction. Exogenous tissue inhibitor of metalloproteinases-3 protein expression was visualized by immunostaining with monoclonal antibody 12CA5 against the hemagglutin epitope. Three days after transfection of tissue inhibitor of metalloproteinases-3 gene into retinal pigment epithelium cells, intense laser photocoagulation was performed and the incidence of choroidal neovascularization was assessed by fluorescein fundus angiography.

RESULTS

Exogenous tissue inhibitor of metalloproteinases-3 mRNA expression in the choroid and retina was detected on day 3. The efficiency of tissue inhibitor of metalloproteinases-3 gene transfection into retinal pigment epithelium cells was greatest on day 7 and decreased gradually thereafter. The incidence of choroidal neovascularization in tissue inhibitor of metalloproteinases-3 gene-transfected eyes was markedly decreased compared with controls.

CONCLUSIONS

This study shows that tissue inhibitor of metalloproteinases-3 gene can be transferred into rat retinal pigment epithelium using the hemagglutinating virus of Japan-liposome method and that tissue inhibitor of metalloproteinases-3 gene overexpression can inhibit development of experimental choroidal neovascularization. This method may represent a future treatment modality for human macular degeneration associated with choroidal neovascularization.

A high incidence of Staphylococcus aureus colonization in the external eyes of patients with atopic dermatitis

OBJECTIVE

To determine the frequency distribution of bacteria on the external surface of eyes of patients with atopic dermatitis (AD) and to investigate the relationship between the frequency of bacterial colonization and the grade of atopy or ocular diseases associated with AD.

DESIGN

Comparative cross-sectional study.

PARTICIPANTS

Thirty-six AD patients (mean age, 24.5 years) and 16 nonatopic, age-matched control participants (mean age, 25.5 years).

INTERVENTION

The eyelid margins and conjunctival sacs were scraped with sterile swabs. These samples were inoculated into aerobic and anaerobic culture media.

MAIN OUTCOME MEASURES

The frequency distribution of bacteria isolated from the eyelid margins and conjunctival sacs.

RESULTS

Bacteria isolated from AD patients were: Staphylococcus aureus in 21 of 36 patients (including methicillin-resistant Staphylococcus aureus in two patients); Staphylococcus epidermidis in two patients (including methicillin-resistant Staphylococcus epidermidis in one patient); other coagulase-negative Staphylococcus in six patients;alpha-streptococcus in three patients; Corynebacterium species in three patients; Neisseria species in two patients; and Propionibacterium acnes in one patient. From the nonatopic control participants, we isolated S. aureus in one patient, S. epidermidis in two patients and alpha-streptococcus in one patient. S. aureus was isolated from 67% of the AD patients, and any type of bacteria was isolated from 86% of the patients. These rates were significantly higher than those of nonatopic control participants (6% S. aureus and 25% any bacteria). There was no significant relationship between the frequency distribution of bacteria and the grade of atopy or associated ocular diseases.

CONCLUSIONS

High rates of bacterial colonization, especially S. aureus, were found in the conjunctival sacs and eyelid margins of AD patients. In case management of AD patients, this unique distribution of bacteria must be carefully considered.

Molecular cloning and expression of cDNA encoding chicken UDP-N-acetyl-D-glucosamine (GlcNAc): GlcNAcbeta 1-6(GlcNAcbeta 1-2)- manalpha 1-R[GlcNAc to man]beta 1,4N-acetylglucosaminyltransferase VI

A cDNA that encodes UDP-N-acetyl-d-glucosamine (GlcNAc):GlcNAcbeta1-6(GlcNAcbeta1-2)Manalpha1-R[GlcNA c to Man]beta1, 4N-acetylglucosaminyltransferase VI (GnT VI), which is responsible for the formation of pentaantennary asparagine-linked oligosaccharides (N-glycans), has been cloned from a hen oviduct cDNA library based on the partial amino acid sequences of the purified enzyme. The isolated cDNA clone contained an open reading frame encoding 464 amino acids, including all of the peptides that were sequenced. The deduced amino acid sequence predicts a type II transmembrane topology and contains two potential N-glycosylation sites. The primary structure was found to be significantly similar to human GnT IV-homologue, the gene for which was cloned from the deleted region in pancreatic cancer, and to human and bovine GnT IVs. Chicken GnT VI-transfected COS-1 cells showed a high GnT VI activity (26.8 pmol/h/mg protein), whereas nontransfected, mock-transfected, or human GnT IV-homologue-transfected COS-1 cells had no activity. Northern blot analysis using poly(A)(+) RNA from hen oviduct indicated that the size of GnT VI mRNA is 2.1 kilobases. Reverse transcription-polymerase chain reaction analysis showed that GnT VI mRNA was relatively highly expressed in oviduct, spleen, lung, and colon.

Minimizing radial-keratotomy-induced diurnal variation in vision using contact lenses

A 41-year-old man with 16 radial keratotomy (RK) incisions in each eye reported a paradoxical diurnal variation in vision in both eyes with low Dk/L soft contact lenses. After rk, the patient experienced the conventional diurnal change a morning-to-evening mean (right and left eyes) myopic change of -1.80 diopters (D). However, while wearing low Dk/L contact lenses, a paradoxical morning-to-evening mean hyperopic change of 2.30 D was found. The diurnal variation was minimized (0.50 D) by wearing high Dk/L contact lenses. These results suggest that contact lenses can be used to treat diurnal variation in manifest refraction after RK by inducing appropriate stress.

Mutations in the 11-cis retinol dehydrogenase gene in Japanese patients with Fundus albipunctatus

PURPOSE

To detect mutations in the RDH5 gene encoding 11-cis retinol dehydrogenase in patients from Japan with fundus albipunctatus.

METHODS

Polymerase chain reaction and direct genomic sequencing techniques were used to detect mutations of the RDH5 coding exons (exons 2-5) in two unrelated patients with fundus albipunctatus. Selected alleles that altered the coding region or intron splice sites were evaluated further through segregation analysis in the families of the index cases.

RESULTS

Two novel RDH5 mutations were identified. One of these was a missense mutation Val264Gly in exon 5, and the other was an in-frame insertion of 3 bp in exon 5.

CONCLUSIONS

The data indicate that mutations in RDH5 are the primary cause of fundus albipunctatus.

Argatroban inhibits intraocular fibrin formation after vitrectomy in rabbits

OBJECTIVES

To examine whether the specific thrombin inhibitor argatroban can prevent anterior chamber, pupillary area, and anterior vitreous fibrin formation after vitrectomy and lensectomy in rabbits.

METHODS

Argatroban was infused into the vitreous cavities of Japanese albino rabbits for 5 minutes after pars plana vitrectomy and lensectomy. Slitlamp microscopy and indirect ophthalmoscopy were performed at postoperative hours 0.5, 1, 2, 3, and 6, and at postoperative days 1, 2, 3, and 7, and the amounts of fibrin formation in the anterior chamber, pupillary area, and anterior vitreous were scored from grade 0 to 4.

RESULTS

Argatroban prevented fibrin formation from 0.5 hours postoperatively in a dose-dependent manner. In the eyes treated with 0.01% argatroban, the median score for postoperative fibrin formation was significantly less than that in control eyes between hours 1 and 3 (hour 1, P =.02; hour 2, P =.005; and hour 3, P =.003); the eyes treated with 0.003% argatroban also had significantly less fibrin than control eyes between 1 and 2 hours (hour 1, P =.005; hour 2, P =.03).

CONCLUSION

These results indicate that argatroban inhibits intraocular fibrin formation in an experimental rabbit model.

CLINICAL RELEVANCE

Argatroban may be useful clinically in cases that often produce fibrin postoperatively, such as proliferative vitreoretinopathy and proliferative diabetic retinopathy.

New soft-tipped instruments for foveal translocation surgery with 360 degrees retinotomy

Foveal translocation surgery with 360 degrees retinotomy involves several surgical procedures, including creation of a total retinal detachment, rotation of the retina, and complete reattachment of the retina. Some of these procedures, which are time-consuming and difficult to perform, may damage the retina when conventional surgical instruments are used. To make these procedures safer and easier, we have developed 3 soft instruments: an atraumatic forceps, a modified Chang double-barrel cannula with a silicone tip, and a light pipe with a silicone tip. The atraumatic forceps allows the surgeon to grasp and peel off the retina with less damage during the creation of retinal detachment. A bimanual technique using the other 2 instruments allows surgeons to rotate and reattach the detached retina easily and safely. We believe that these soft-tipped instruments make foveal translocation a less complicated surgery.