Floorball-related eye injuries: The impact of protective eyewear.

Several previous studies have shown that floorball belongs to a high-risk group of sports in terms of eye injuries. Protective eyewear is available, but the extent of its use and impact on eye injuries are unknown. The purpose of this study was to investigate the current incidence of eye injuries caused by floorball and to compare it with the present use of protective eyewear. Medical records were used to identify all eye injuries suffered while playing floorball in Jönköping County from 2008 to 2011 (N = 167). All these patients were sent a questionnaire that included inquiries about the use of protective eyewear. The study shows that floorball caused more eye injuries than all other sports combined (56%). Prolonged decreased visual acuity was very unusual (0.5%), but moderate eye injuries with some risk of future problems were seen in 62% of the sample. More than one fifth of the injured patients reported some kind of vision-related problem 2-7 years after the original injury. Only one player had been using protective eyewear at the time of injury. Our results underline the importance of protective eyewear to prevent floorball-related injuries.

Neuroretinal xenotransplantation to immunocompetent hosts in a discordant species combination.

In spite of its immune privileged state, xenotransplantation within the CNS is associated with rapid graft destruction in immunocompetent hosts. Efforts to enhance graft survival have mostly focused on host immune response, whereas relatively little attention has been paid to donor tissue characteristics. In the present paper, we explore long-term survival of xenogeneic full-thickness neuroretinal transplants in immunocompetent hosts and investigate the significance of tissue integrity in relation to graft survival. Adult rabbits receiving no immunosuppression were used as hosts and fetal Sprague-Dawley rat neuroretina as donors. Using vitreoretinal surgical techniques, rabbits received either a full thickness or a fragmented neuroretinal graft to the subretinal space of one eye. Eyes receiving full-thickness grafts were examined morphologically after 91 days and fragmented grafts after 7-14 days. Surviving full thickness grafts were found in six of eight eyes, four of which displayed the normal laminated appearance. Major histocompatibility complex (MHC) up-regulation in surviving grafts was minimal and they contained a well-organized photoreceptor layer, protein kinase C (PKC) labeled rod bipolar cells, parvalbumin labeled AII amacrine cells and glial fibrillary acidic protein (GFAP) labeled Müller cells. Fragmented grafts (n=6) were all destroyed or showed severe signs of rejection. A mass of inflammatory cells derived from the choroid was evident in these specimens, and no labeling of retina-specific cells was seen. We conclude that full-thickness rat neuroretina can survive for several months after subretinal transplantation to the subretinal space of immunocompetent rabbits, while fragmented counterparts are rapidly rejected. Surviving full-thickness grafts can develop many of the normal retinal morphological characteristics, indicating a thriving relationship between the initially immature donor tissue and its foreign host. Our results strongly indicate that donor tissue integrity is a crucial factor for graft survival in CNS xenotransplantation.

Tailored vitrectomy and laser photocoagulation without scleral buckling for all primary rhegmatogenous retinal detachments.

AIM: To investigate the anatomical and functional results and the complications in eyes operated on using vitrectomy without scleral buckling for all forms of rhegmatogenous retinal detachment (RRD). METHODS: All cases of primary RRD at the University Hospital of Lund, Lund, Sweden, treated by one surgeon during a period of 3 years were retrospectively reviewed. In 131 (98%) of 134 consecutive cases, a final follow-up record of 3-14 months was obtained, and these eyes were included in the study. The surgical protocol was tailored for each case and consisted of vitrectomy, laser photocoagulation and tamponade. Preoperative and intraoperative variables were analyses for risk for redetachment and postoperative proliferative vitreoretinopathy (PVR). RESULTS: Complete reattachment was achieved in 87% of cases (114/131) after one operation and in 95% cases after > or =1 operation. A primary detachment of >1 quadrant was the only significant risk factor for redetachment (p<0.05). The most common cause of redetachment was progressive PVR. Significant risk and factors for PVR postoperatively were a poor preoperative visual acuity and a high number of laser effects during surgery (p<0.05). The visual acuity for the total number of eyes, macula-off eyes, and pseudophakic as well as phakic eyes, improved significantly. The visual acuity for macula-on eyes did not change significantly. Six patients developed ocular hypertension and another 6 an epiretinal membrane. Three patients reported a visual field defect. Increased lens opacification was seen in 64 of the 94 (68%) phakic eyes. CONCLUSIONS: The tailored vitrectomy protocol is well suited to all types of RRD. Increased lens opacification in phakic eyes is common, but visual acuity is considerably improved in phakic as well as pseudophakic eyes. PVR development postoperatively is related to the extent of laser treatment, indicating that the protocol may be even further optimised in the future.

Adult rabbit retinal transplants.

PURPOSE: To study the survival of adult retinal grafts prepared in a physiologically optimized way. METHODS: Twenty-three rabbits received an adult full-thickness rabbit retinal transplant positioned under the host retina, using a vitrectomy technique. The transplants were prepared using a procedure based on a previously described in vitro model used for physiological experiments on the adult retina. Five rabbits received a fragmented graft. All grafts were prelabeled with 4',6-diaminidin-2-phenylindoldihydrochloride (DAPI) to allow identification. The eyes were examined by light and fluorescence microscopy 6 to 174 days after surgery. To assess the amount of cell death in the graft before actual transplantation, in vitro experiments were performed. The extent of cell death in retinas prepared by the optimized protocol was examined and compared with a simpler preparation previously used successfully for embryonic grafts. The amount of cell death in the in vitro experiments was evaluated using a fluorescent green nucleic acid stain that penetrates dying cells. RESULTS: In 21 of the 23 animals that received full-thickness grafts prepared in an optimized way, the transplant survived. Sixteen grafts, including all four with a 174-day survival time, displayed normal morphology, with all retinal layers preserved. The fragmented grafts survived poorly. The in vitro experiments showed minimal cell death in retinas prepared according to the optimized protocol, whereas control retinas displayed extensive cell death after 5 hours. CONCLUSIONS: The results showed that it is possible to transplant adult retina in the rabbit and that the grafts survive well if they are prepared under physiologically optimized conditions and the integrity of the grafted tissue is kept intact.

Cone photoreceptors in laminated retinal transplants.

PURPOSE: To investigate the contents of green- and blue-sensitive cone photoreceptors in laminated rabbit retinal transplants. METHODS: Eleven rabbits each received a sheet of embryonic neuroretina into the subretinal space in one eye. Vitrectomy was used in the procedure and properly polarized flat transplants were placed on the host pigment epithelium. After 17-309 days the transplants were examined immunohistochemically with specific antibodies against COS-1 (green-sensitive cones) and OS-2 (blue-sensitive cones). RESULTS: All grafts displayed normal lamination with well developed photoreceptor outer segments apposed to the host retinal pigment epithelium. Occasionally, rosettes were found at the transplant edges. Both COS-1 positive and OS-2 positive cones were detected. In the laminated part of the grafts, COS-1 positive cones were more numerous than OS-2 positive ones. In the rosetted parts of the transplants the relationship between the cones was reversed. CONCLUSION: Full-thickness embryonic rabbit retinal transplants develop into laminated retinas with well-developed photoreceptor outer segment. Both green- and blue-sensitive cone photoreceptors are present and the ratio between the two cone types is the same as in the normal adult rabbit retina.

Survival of full-thickness retinal xenotransplants without immunosuppression.

BACKGROUND: A study was carried out to explore the survival of xenogeneic full-thickness retinal transplants in the subretinal space of hosts without immunosuppression. METHODS: Nine adult rabbits received a complete immature rat neuroretina in the subretinal space. No immunosuppression was given, and the animals were followed up for 15 or 34 days. The eyes were then examined histologically with hematoxylin and eosin staining as well as with antibodies against major histocompatibility complex (MHC) classes I and II, and the retinal pigment antigen RPE-65. RESULTS: Surviving grafts were found in five out of nine eyes. Three grafts displayed the laminated appearance of a normal retina, and two had developed into rosettes. In four of the five specimens with surviving grafts, the host retinal pigment epithelium (RPE) was continuous, and MHC labeling showed no or minimal upregulation. In four specimens, no graft was found. Three of these displayed RPE defects and an increase in MHC class I- and II-labeled cells in the host choroid, subretinal space and host neuroretina. CONCLUSIONS: Full-thickness xenogeneic neuroretinal grafts can survive for at least 34 days in an adult host without immunosuppression. Immature grafts can develop the laminated appearance of a normal retina. The integrity of the host RPE seems to correlate with graft survival. We conclude that xenogeneic retinal grafts can survive and develop if the integrity of the donor tissue is intact and if damage to the RPE is minimal.

MHC expression in fragment and full-thickness allogeneic embryonic retinal transplants.

BACKGROUND: The study was carried out to evaluate the expression of major histocompatibility complex (MHC) molecules in retinal transplants with different tissue integrity. METHODS: Twelve adult rabbits received an allogeneic subretinal neuroretinal transplant, in the form of either fragmented embryonic cells or a complete full-thickness embryonic retina. A controlled transvitreal approach was used for both transplantation types. The grafts were examined histologically after 31 or 49 days with hematoxylin and eosin staining and immunohistochemical analysis of MHC class I and class II expression. RESULTS: All five fragment transplants developed into rosettes. Two of them displayed MHC class I-labeled cells, and four MHC class II-labeled cells. The cells were concentrated on the scleral side of the graft, and there was also a marked increase of labeled cells in the choroid. MHC labeling was often associated with defects in the retinal pigment epithelium. Six of the seven full-thickness grafts displayed a laminated morphology with well-developed retinal layers. The seventh consisted of rosettes. None of these grafts displayed MHC class I- or class II-labeled cells. CONCLUSIONS: The findings suggest that host immune response against fragmented and intact neuroretinal grafts is different, indicating tissue integrity as one factor affecting graft-host immune interactions. The absence of immune response in full-thickness grafts is encouraging and important in the struggle to find therapies for retinal degenerative disease.

Full-thickness retinal transplants: a review.

Embryonic full-thickness rabbit neuroretinal sheets were transplanted to the subretinal space of adult hosts. This was accomplished by using a new transplantation technique involving vitrectomy and retinotomy. The grafts were followed from 10 to 306 days after surgery and were then examined by different histological techniques. In the light microscope, the transplants were seen to develop the normal retinal lamination and fusion with the host retina, especially after long survival times. Ultrastructurally, normal photoreceptor outer segments, well integrated with the host retinal pigment epithelium, were found. Growth cones were present in the zone of fusion between graft and host retina. Immunohistochemical labeling revealed many of the normal retinal components not previously found in retinal transplants, and graft-host connections between neurons in the rod pathway were seen. The morphology of vibratome-sectioned neuroretinal sheets as well as adult full-thickness grafts was also examined. These transplantation types showed less of the normal morphology compared with embryonic full-thickness grafts. The immunogenicity of embryonic full-thickness and fragmented grafts was compared using major histocompatibility complex immunolabeling. Fragmented grafts elicited a response from the host immune system similar to a chronic transplant rejection. This reaction was absent in the full-thickness grafts which is in accordance with their good long-term survival.

Partial and full-thickness neuroretinal transplants.

Adult and embryonic rabbit retinal sheets were transplanted into the subretinal space of adult rabbits. The transplants were either full-thickness with intact layering, or gelatin embedded and vibratome sectioned with the inner retina removed. The full-thickness grafts were positioned subretinally by means of a glass capillary in which they were partially folded. The vibratome sectioned ones were placed using a plastic injector in which the gelatin embedded graft was flat. The embryonic full-thickness grafts were followed clinically up to 3 months, and the other 3 transplant types up to 1 month postoperatively, after which the retina was sectioned and stained for light microscopy. Surgical complications were more common in eyes receiving vibratome sectioned grafts with 10 out of 34 eyes displaying blood in the vitreous. Four of these eyes also developed total retinal detachment. Out of 17 eyes receiving full-thickness grafts, only one displayed these complications. Histologically, 11 out of 13 embryonic full-thickness transplants revealed straight, laminated transplants with correct polarity, and with all normal retinal layers present. In these transplants, fusion with the host increased in time. Of the adult full-thickness transplants, only 1 out of 4 survived, and this graft showed signs of degeneration. The vibratome sectioned adult transplants in a few cases survived the first two postoperative weeks. In these grafts, both inner and outer retina were present, indicating an incomplete vibratome sectioning. With longer postoperative times, the number of surviving transplants in this group diminished considerably. All vibratome sectioned embryonic transplants developed into rosettes and sometimes also into laminated sections with reversed polarity. It can be concluded that in rabbits, the surgical technique used for vibratome sectioned transplants requires a larger sclerotomy and retinotomy, since they have to be kept flat in the transplanting instrument due to the surrounding gelatin. This technique is associated with a higher frequency of complications than the one used for full-thickness grafts which are more flexible and can be transplanted with a smaller instrument. Vibratome sectioning of embryonic grafts results in abnormal morphology and their adult counterparts only survive if the sectioning is incomplete. Adult full-thickness grafts show poor survival. Embryonic full-thickness transplants in the majority of cases develop into laminated retinas with layers parallel to the host retinal pigment epithelium. They also survive and integrate well with the host retina.

Graft-host connections in long-term full-thickness embryonic rabbit retinal transplants.

PURPOSE: To establish neuronal connections in the rod and cone pathway between laminated rabbit retinal transplants and the host retina. METHODS: Fourteen adult rabbits received a complete full-thickness embryonic transplant. After survival times of 3 to 10 months, the retinas were studied under light microscope and with immunohistochemistry. Antibodies against protein kinase C (PKC), parvalbumin, and calbindin were used to label rod bipolar cells, AII amacrine cells, and cone bipolar cells, respectively. The AB5 antibody was used to label ganglion cells. RESULTS: The transplants displayed laminated morphology with layers parallel to the host retinal pigment epithelium. In the oldest specimens (10 months after surgery), laminated layers of graft and host approached each other and almost reconstructed the normal retinal appearance. The ganglion and cone bipolar cells of the host survived well, as was seen with AB5 and calbindin double-labeling. Connections between cone bipolar cells in the graft and ganglion cells in the host were not common. PKC-labeled rod bipolar cells and parvalbumin-labeled AII amacrine cells of host and graft showed sprouting activity directed toward an intermediate plexiform layer located between the graft and host. In specimens double-labeled with PKC and parvalbumin, this intermediate plexiform layer was seen to contain numerous PKC- and parvalbumin-labeled processes. Direct connections between rod bipolar and AII amacrine cells in host and graft were seen in the 10-month specimens. CONCLUSIONS: Full-thickness embryonic transplants survive for at least 10 months, and normal laminated morphology develops. Host and graft fuse and together contribute nerve cell processes to an intermediate plexiform layer. Direct graft-host contacts are also present between neuronal types that in the normal retina participate in the rod pathway.

Long-term full-thickness embryonic rabbit retinal transplants.

PURPOSE: To establish the light and electron microscopic morphology of long-term full-thickness embryonic rabbit retinal transplants, with special attention paid to graft- host integration. METHODS: Eighteen rabbits received a complete embryonic neuroretina 19 days after conception. The transplants were positioned under the host retina, flat against the host retinal pigment epithelium with proper polarity, using a vitrectomy technique. After surviving 3 to 10 months, the transplants were examined by light and electron microscopy. RESULTS: The outer retina of the host had degenerated in all specimens. In 16 of the 18 eyes, well-laminated transplants with correct polarity, measuring up to 3.2 mm in length, were found. The transplants displayed long outer segments facing the host retinal pigment epithelium, and they were laminated to the level of the inner plexiform layer in which fusion with the host was often evident. Fusion was more prominent in the oldest transplants. Electron microscopy revealed bundles of neurites at different levels of maturation in close contact with Müller cell fimbriae at regular intervals along the graft-host border. CONCLUSIONS: Full-thickness embryonic rabbit retinal transplants positioned with correct polarity develop into large laminated retinas and survive without immunosuppression for at least 10 months. Host and graft adapt and almost reconstruct the normal retinal appearance. Ultrastructurally, well-developed photoreceptors and many normal synapse types are seen, and neuron sprouting is evident at the graft-host border.

Immunohistochemical markers in full-thickness embryonic rabbit retinal transplants.

PURPOSE: To examine immunohistochemical markers in straight, well-laminated retinal transplants with special attention paid to the interphotoreceptor matrix, the Müller cells and the ganglion cells as these three retinal components have been abnormal in transplants produced by previous methods. METHODS: Nine rabbits underwent subretinal transplantation of a complete full-thickness embryonic neuroretina. After 31 or 49 days, the transplants were stained for light microscopy and processed for immunohistochemistry. RESULTS: Six of 9 eyes contained transplants with straight, well-laminated regions with all light-microscopic characteristics of a normal retina. In the outer segment region, the expression of peanut agglutinin showed segmental labeling of cone domains in the interphotoreceptor matrix, and interphotoreceptor retinoid binding protein immunoreactivity was found. Glial fibrillary acidic protein and vimentin immunoreactivity revealed normal Müller cell morphology. In 3 transplants the AB5-antibody-labeled ganglion cells in the ganglion cell layer and all transplants contained nerve fibers in the nerve fiber layer labeled by an antibody against neurofilament of 160 kD. The latter also labeled fibers connecting the transplant with the host. CONCLUSIONS: Full-thickness embryonic retinal transplants develop the normal retinal appearance and display several of the retinal components necessary for normal function which are not found in transplants produced by previous methods.

Transplant of full-thickness embryonic rabbit retina using pars plana vitrectomy.

PURPOSE: To develop an improved surgical technique making full-thickness retinal transplant possible, thereby achieving a normal laminated transplant with minimal rosette formation. METHODS: A total of 23 rabbits underwent vitrectomy, retinotomy, and subsequent subretinal transplant of a complete embryonic neuroretina using a specially crafted glass cannula. Of the 23 animals, 15 received a prenatal day 16 or 19 (E16 or E19) retina; the remaining eight received an E15 retina. The animals were followed from 10 to 35 days, and after this period, the transplants were sectioned and stained for light microscopy. RESULTS: In 11 of the 15 transplants with E16 or E19 donors, histology showed regions up to 1.8 mm of straight, correctly positioned transplants with layering corresponding to their age. The eight animals kept alive longest postoperatively, 31 or 35 days, all showed normal retinal layers, including photoreceptor outer segments appositioned against the host retinal pigment epithelium. Tissue from the youngest donors (E15) yielded less well-organized transplants, indicating a critical stage in retinal embryogenesis before which transplant in this respect is less favorable. CONCLUSIONS: Our procedure makes it possible to transplant embryonic retina to the appropriate position adjacent to the host retinal pigment epithelium, keeping the transplant architecture intact. The transplants show good layering and well-developed photoreceptors abutting the retinal pigment epithelium.

Sports-related eye injuries.

At the University Eye Hospital of Lund 272 patients were treated following blunt trauma during a two and half year period. The number of cases related to sports activity were extracted. The major sports responsible for the injuries and the type of injuries were identified and also an investigation into the sex and age distribution was made. Forty percent of the total number of cases were sports-related. Floor ball was responsible for 46% of these cases.