Retinitis pigmentosa (RP) is the leading cause of hereditary blindness, and there is currently no available treatment that can either significantly slow the progression of this disease or restore lost vision. Amphibians and birds exhibit different strategies for retinal regeneration, including the proliferation of cells in the ciliary margin and transdifferentiation of the retinal pigment epithelium (RPE) and Muller glia. The mammalian retina does not have the innate ability to regenerate damaged retina, but research is actively exploring pathways that promote endogenous regeneration. Because the inner retinal architecture is largely preserved, even in advanced cases of RP, an alternative is to replace the degenerated photoreceptor cells, thereby replenishing the photoreceptor population. The transplantation of embryonic stem cells, induced pluripotent stem cells, embryonic retinal progenitors (postmitotic photoreceptor precursors), and hippocampal neuronal progenitors have been investigated for this purpose. The encouraging results demonstrate the integration and possible functional connection between the transplanted cells and the inner retinal circuitry of the host. In this review, we summarize recent advancements in this field and their potential for the treatment of RP and other retinal degenerations.

Retinitis pigmentosa (RP) is a leading cause of blindness worldwide and lacks effective clinical treatment. Stem cell-based therapy offers a novel experimental therapeutic approach, based on the strategy that transplanted progenitor cells can replace or rescue damaged photoreceptor cells. However, many factors remain to be determined, for example, what is the optimal time to choose for targeting the host tissue during the progression of the degeneration, what the characteristics and potential capacities in different stem cells, do stem cells differentiate into functional daughter cells, and to what degree can host retinal function be restored? We have used Royal College of Surgeons rats and light-induced retinal degeneration minipigs as animal models of retinitis pigmentosa to study the effectiveness of cell transplant therapies and the functional capacity of the host retina. Stem cells from rat retina and bone marrow, neonatal pig, and human fetal retina have been investigated to find the proper donor cells. The dedifferentiation and then redifferentiation of Müller cells following retinal stem cell transplantation may contribute to host visual function and presents a promising line of research.

Purpose: The purpose of this study was to determine whether interleukin (IL)-4 genetic variants are associated with age-related macular degeneration (AMD). Methods: The genotyping of IL-4 -590 and intron 3 variable number of tandem repeats (VNTR) was conducted for 171 patients with AMD and 134 controls by using TagMan and polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) assays. Results: There was no difference in distribution of age, sex, body mass index, and status of systemic disease between AMD patients and healthy controls. Significantly, more patients were current smokers in the AMD group compared with the controls (p = 0.038). The genotypes of IL-4 -590 and intron 3 VNTR were associated with the risk of AMD in our results. In the stratification analysis, both IL-4 -590 allelic type and smoking status were independently associated with AMD. No interactions between allelic type and smoking were found to contribute to risk of AMD. The mean AMD score was significantly higher in carriers with IL-4 -590 T/T or T/C genotypes compared with those with C/C. Conclusions: Our results support the hypothesis that polymorphisms of IL-4 -590 and intron 3 VNTR might be a genetic marker for the development of AMD.

Purpose: To elucidate the anatomical and visual outcomes of patients with idiopathic epiretinal membranes (ERM) who underwent vitrectomy, membrane removal only, or with internal limiting membrane (ILM) peeling under the assistance of different dyes. Methods: A retrospective chart review of patients with idiopathic ERM who received surgical treatment between January 2004 and December 2009. The patients were grouped according to the usage of staining materials assisting ILM peeling. Group 1 consisted of 61 eyes that underwent conventional vitrectomy and ERM peeling without staining-assisted ILM peeling. Group 2 consisted of 20 eyes with triamcinolone acetonide-assisted ILM peeling following conventional vitrectomy. Group 3 consisted of 23 eyes with indocyanine green-assisted ILM peeling following conventional vitrectomy. Results: This study included 104 eyes from 104 patients. There was no significant difference in age, sex, preoperative visual acuity, retinal thickness or follow-up duration among the three groups. Overall, the mean best-corrected visual acuity improved significantly from baseline 0.15 to postoperative 0.41 (p < 0.0001). Among the three groups, the mean logarithm minimum angle of resolution acuity markedly improved. There was no significant difference in postoperative visual acuity among groups. As measured by ocular coherent tomography, the mean central foveal thickness decreased from 465.21 ± 86.18 to 299.16 ± 70.14 mm. Although there was no difference between groups, postoperative retinal thickness was thicker than that observed in the normal population. The incidence of recurrent ERM was 13.1% in Group 1 and 0% in Groups 2 and 3; this incidence was significantly higher than in the conventional surgery group. Visual outcome was statistically more deteriorated in recurrent cases than in nonrecurrent cases (p = 0.011). Conclusions: ERM surgeries with or without dye-assisted ILM peeling showed similar results. Moreover, the incidence of recurrence is lower in the ILM peeling groups and plays a primary role in determining the final postoperative vision outcome.

Purpose: This study was conducted to determine the incidence, risk factors, and treatment for retinopathy of prematurity (ROP) among very low birth weight (VLBW) infants. Methods: This work is a retrospective, observational analysis of all VLBW infants managed at National Taiwan University Hospital from 2002 to 2005. Results: The chart data of 96 VLBW infants were reviewed. Seven of the 96 infants (7.3%) were noted to have no ROP, while 18 infants (18.7%) had minor ROP (stage 1 and stage 2 ROP) and 71 infants (74%) had severe ROP (greater than stage 2 ROP). With lower gestational age, lower birth body weight, greater degree of respiratory distress syndrome, prolonged use of oxygen, and without maternal history of antenatal steroid use, the incidence of severe ROP (greater than stage 2) increased significantly (p < 0.001, p < 0.001, p = 0.01, p < 0.001, and p = 0.03, respectively). Conclusion: More severe ROP may correlate with lower gestational age, lower birth body weight, and longer oxygen use. Use of antenatal steroid would decrease the incidence of severe ROP.

Purpose: The purpose of this study was to investigate the treatment efficacy of photodynamic therapy (PDT) with verteporfin for patients suffered from polypoidal choroidal vasculopathy. Methods: In this retrospective comparative study, we included 25 eyes of 25 patients with macula-involved polypoidal choroidal vasculopathy. All patients had follow-up of more than 3 years. We compared the best-corrected visual acuity (BCVA) in logarithm of minimal angle of resolution (logMAR) scale at each follow-up time points with initial baseline BCVA. We also investigated the factors influencing final BCVA at the 36-month follow-up time point. Results: At 6 months, the mean BCVA improved from 0.77 to 0.68 (p = 0.024). All the mean BCVAs after the 6-month follow-up time points were still better than baseline mean BCVA, but the improvements were not significant statistically. The mean BCVAs became 0.68, 0.74, 0.75, 0.73, and 0.72 respectively at 12-month, 18-month, 24-month, 30-month, and 36-month follow-up time points. Better initial BCVA (p = 0.012) and smaller lesion size (p = 0.031) significantly predicted the better final visual improvement at 36 months rather than sex (p = 0.7) and age (p = 0.206). Conclusion: Although the visual improvement after treatment of PDT with verteporfin was only temporarily significant, the prevention of visual deterioration in these patients persisted during a 3-year follow-up. Better initial BCVA and smaller lesion size were significant factors influencing final visual improvement, and early treatment might be suggested.

Chiasmal optic neuritis (ON), a rare condition that affects the optic chiasm, is mostly associated with inflammatory demyelinating disorders and may be the initial manifestation of multiple sclerosis (MS). Here, we reported three cases of MS with chiasmal optic neuritis. The clinical manifestations, neuro-imaging results, and visual prognosis were evaluated in each patient. Routine eye examinations and auxiliary examinations, including Ishihara color plate, determination of the visual field (VF), and magnetic resonance imaging (MRI) of the optic nerve and chiasm, were performed. All patients presented with reduced VA and VF defects. The abnormal enhancement of the optic chiasm was clearly demonstrated on MRI. Two patients recovered after the systemic administration of steroids, but the other patient only partially recovered. In conclusion, although it is rare, chiasmal ON should be considered in patients who develop bitemporal hemianopia. MRI is the modality of choice for accurate diagnosis. Early diagnosis and proper treatment are mandatory for the restoration of restore visual function.

Duane’s retraction syndrome (DRS) is a predominately congenital eye movement disorder. We present a 23-year-old female with unilateral DRS, which was diagnosed by magnetic resonance imaging (MRI), and associated symptoms of unilateral crocodile tears and bilateral high-frequency hearing loss. This case highlights that DRS may be associated with various systemic malformations. For children with newly diagnosed DRS, we recommend comprehensive evaluation for any associated abnormalities. For adults with DRS complaining of discomfiture associated with a noncentral head position, we suggest a complete examination, including strabismus tests, the forced duction test, and even MRI, to evaluate the degree of muscle modification and to identify the most suitable treatment strategy.