Retinal expression of Fgf2 in RCS rats with subretinal microphotodiode array.

PURPOSE: To test the hypothesis that subretinal electrical stimulation from a microphotodiode array (MPA) exerts a neuroprotective effect in Royal College of Surgeons (RCS) rats through the induction of growth factors. METHODS: At postnatal day 21, RCS rats were divided into four groups in which one eye per rat received treatment: (A) active MPA, (M) minimally active MPA, (S) sham surgery, or (C) no surgery and the opposite eye was unoperated. Dark- and light-adapted ERGs were recorded 1 week after surgery. A second set of A-, M-, and C-treated RCS rats had weekly ERG recordings for 4 weeks. Real-time RT-PCR was used to measure relative expression of mRNAs (Bdnf, Fgf2, Fgf1, Cntf, Gdnf, and Igf1) in retina samples collected 2 days after the final ERG. RESULTS: One week after surgery, there was a slight difference in dark-adapted ERG b-wave at the brightest flash intensity. Mean retinal Fgf2 expression in the treated eye relative to the opposite eye was greater for the A group (4.67 +/- 0.72) than for the M group (2.80 +/- 0.45; P = 0.0501), S group (2.03 +/- 0.45; P < 0.01), and C group (1.30 +/- 0.22; P < 0.001). No significant change was detected for Bdnf, Cntf, Fgf1, Gdnf, and Igf1. Four weeks after surgery, the A group had significantly larger dark- and light-adapted ERG b-waves than for the M and C groups (P < 0.01). Simultaneously, mean relative Fgf2 expression was again greater for the A group (3.28 +/- 0.61) than for the M (1.28 +/- 0.32; P < 0.05) and C (1.05 +/- 0.04; P < 0.05) groups. CONCLUSIONS: The results show subretinal implantation of an MPA induces selective expression of Fgf2 above that expected from a retina-piercing injury. Preservation of ERG b-wave amplitude 4 weeks after implantation is accompanied by elevated Fgf2 expression. These results suggest that Fgf2 may play a role in the neuroprotection provided by subretinal electrical stimulation.

Pars plana vitrectomy, internal limiting membrane peeling, and panretinal endophotocoagulation for macular edema secondary to central retinal vein occlusion.

PURPOSE: To investigate the visual and anatomic outcomes in eyes with cystoid macular edema (CME) resulting from central retinal vein occlusion (CRVO) that underwent pars plana vitrectomy, internal limiting membrane peeling, and panretinal endolaser photocoagulation (PPV/MP/EL). DESIGN: Retrospective, observational case series. METHODS: Consecutive, nonrandomized patients at the Duke Eye Center who underwent PPV/MP/EL for treatment of CME secondary to CRVO by a single surgeon (S.F.) over the last 5 years were identified and reviewed. Outcome measures include best-corrected visual acuity (BCVA), foveal thickness, and total macular volume (TMV). RESULTS: Twelve patients were identified. Duration of CRVO before surgery ranged from 3 to 19 months (mean, 12.3 months). Preoperative perfusion status was not ischemic in 6 eyes, ischemic in 5 eyes, and indeterminate in 1 eye. Intravitreal triamcinolone had been administered in 66% and was given at least 4 months before surgical intervention. After surgery, foveal thickness and TMV improved, but BCVA demonstrated only a modest improvement that did not reach statistical significance. At the time of surgery, 50% of eyes were pseudophakic. Of the remaining eyes, visually significant cataracts developed in all 6 (100%) within 1 year after surgery, with 67% of those undergoing cataract extraction within 15 months after PPV/MP/EL. CONCLUSIONS: PPV/MP/EL performed for CME secondary to CRVO reduced foveal thickness and TMV at final follow-up; however, anatomic improvement did not correlate with a statistically significant improvement in BCVA.

Peripheral reticular pigmentary change is associated with complement factor H polymorphism (Y402H) in age-related macular degeneration.

OBJECTIVE: To examine phenotypes of age-related macular degeneration (AMD) patients with the complement factor H (CFH) variant (Y402H, C allele at rs1061170). DESIGN: Clinic-based case series study. PARTICIPANTS: The data set contained a total of 956 unrelated cases of AMD. METHODS: Age-related macular degeneration phenotypes of 796 carriers of the CFH Y402H variant were compared with the AMD phenotypes of 160 noncarriers. MAIN OUTCOME MEASURES: Presence or absence of 34 phenotypic features. RESULTS: Of the 34 features analyzed, only peripheral reticular pigmentary change (PRPC) was associated with this CFH variant (P = 0.0006). The proportion of AMD cases with PRPC correlated with the number of CFH risk C alleles in a dose-response fashion. CONCLUSIONS: The CFH Y402H polymorphism is associated with PRPC, suggesting that AMD changes are not limited to the macula. Current AMD grading methods assess only the macula and should consider incorporating peripheral retinal changes. Phenotypes that suggest a high-risk genotype may prove valuable for diagnostic, therapeutic, and research purposes.

Phenotype analysis of patients with the risk variant LOC387715 (A69S) in age-related macular degeneration.

PURPOSE: To examine phenotypes of age-related macular degeneration (AMD) patients with the LOC387715 variant (T allele at rs10490924, A69S). DESIGN: Retrospective, observational case series. METHODS: This clinic-based case series data set contained 775 unrelated cases of AMD. AMD phenotypes of three groups, determined by the number of LOC387715 risk alleles, were compared regarding the presence or absence of 16 phenotypic features. RESULTS: The number of AMD cases in each group was 164 cases (two risk alleles), 330 cases (one risk allele), and 281 cases (zero risk allele). The mean age at examination for homozygous carriers of the LOC387715 risk allele was significantly lower (73.9 years) than the age for carriers of one (76.4 years) or no (77.1 years) risk allele (P = .0003). Of the 16 features analyzed, only AMD grade (P = .00002) was significantly associated with the LOC387715 variant. As the number of LOC387715 risk alleles increased, the proportion of grade 5 AMD cases increased in a dose-response fashion. CONCLUSIONS: The LOC387715 variant appears to be an independent risk factor for grade 5 (neovascular) AMD. This variant may also be associated with an earlier onset of AMD. Phenotypes that suggest a high-risk genotype may prove valuable for diagnostic, therapeutic, and research purposes.

Neovascular age-related macular degeneration and its association with LOC387715 and complement factor H polymorphism.

OBJECTIVE: To compare phenotypes of 2 age-related macular degeneration (AMD) susceptibility genes: LOC387715 and complement factor H (CFH). METHODS: Phenotypes of 755 AMD cases were characterized. The number of LOC387715 (T allele at rs10490924, or A69S) and CFH (T1277C at rs1061170, or Y402H) risk alleles were determined in each case. Individuals were divided into 5 groups by genotype: group 1, LOC-/- CFH-/-; group 2, LOC+/- CFH-/- or LOC+/+ CFH-/-; group 3, LOC-/- CFH+/- or LOC-/- CFH+/+; group 4, LOC+/- CFH+/-, LOC+/+ CFH+/-, or LOC+/- CFH+/+; and group 5, LOC+/+ CFH+/+. RESULTS: Signs of neovascular AMD including grade (P = .002), pigment epithelial detachment (P = .001), and subretinal hemorrhage (P<.001) demonstrated significant association with groups 2, 4, and 5 vs groups 1 and 3. Group 5 had a significantly younger mean age (72.3 years) compared with other groups (P = .002). CONCLUSIONS: The AMD cases possessing the LOC387715 (rs10490924) variant may have a higher risk of neovascular AMD. Individuals with AMD who are homozygous for both variants might be at greater risk for earlier onset of neovascular AMD.

Retinal neovascularization associated with retinoblastoma.

PURPOSE: To report retinal neovascularization associated with retinoblastoma in a 14-month-old infant. DESIGN: Observational case report. METHODS: Review of clinical and pathologic findings. RESULTS: A large frond of retinal neovascularization was present posterior to the lens in the right eye, which also contained a retinoblastoma. CONCLUSIONS: Retinal neovascularization is an unusual association with retinoblastoma.

Scleral permeability of a small, single-stranded oligonucleotide.

Developing more effective ocular drug delivery systems is essential to improving the treatment of posterior segment eye disease. The large target area provided by the sclera and potentially less vision threatening complications are advantages of transscleral administration compared to more traditional modalities of drug delivery to the posterior segment. We aimed to determine the permeability coefficient for the in vitro diffusion of a small, single-stranded, oligonucleotide across human sclera. Transscleral permeability was measured by placing 100 microL of 2.96 x 10(-4) mol single-stranded, fluorescein-labeled oligonucleotide (MW = 7998.3) on the episcleral surface of sclera mounted in a perfusion chamber. Fractions of choroidal perfusate were collected hourly for 24 hours. The permeability constant or K(trans) for the transscleral diffusion of the naked, single-stranded, fluorescein-labeled oligonucleotide was 7.67 +/- 1.8 x 10(-7) cm/s (mean +/- SEM, N = 7). The permeability constant or K(trans) after intrascleral injection of the same fluorescein-labeled oligonucleotide was 1.32 +/- 0.42 x 10(-7) (mean +/- SEM, N = 4). This analysis demonstrates that diffusion of a naked, 24-base, single-stranded, fluorescein-labeled oligonucleotide can be accomplished by both of the described methods. The ability to deliver single-stranded oligonucleotides across the sclera may prove to be advantageous given the development of several novel therapeutic strategies that use similar molecules.

Sequence analysis of the mouse IRBP gene and cDNA.

PURPOSE: To understand the structure of the mouse interphotoreceptor retinoid-binding protein (IRBP) gene and to compare the predicted primary structure within each repeat of IRBP with its relatives. To compare the levels of expression of IRBP RNA in normal and knockout mice. METHODS: The DNA sequence was determined by sub-cloning restriction fragments of the IRBP gene from 129/Sv P1 clones. Primers were designed to utilize the walking approach. Additional sequences were obtained by PCR amplification from genomic DNA and direct sequencing of products. Mouse retina RNA was subjected to reverse transcription coupled to PCR and the accumulation of double stranded DNA product was monitored with SYBR Green. The PCR primers flanked Intron C, to avoid the analysis of contaminating genomic DNA. RESULTS: Altogether a contig was assembled with a final length of about 14.4 kb. The mouse gene structure is similar to the pattern of exons and introns in the bovine and human genes, with a long first exon encoding most of the protein. The splice site boundaries closely match consensus sequences and the exons appear to be identically placed among the three species (bovine, human, and mouse). A region containing a repeated sequence of low complexity is located about 1.75 to 1.4 kb upstream of the transcription start site. A second region containing another low complexity repeat is found in Intron C close to the end of Exon 3. A limited number of weak consensus polyadenylation signals in the 3' region suggest at least three different transcription terminators that apparently give rise to the previously known mouse IRBP mRNAs. The mRNA for IRBP was detected in normal and part of the mRNA was detected in the IRBP knockout mouse, consistent with previous observations. The level of the IRBP mRNA remnant was reduced about 10 fold in the knockout mouse, also consistent with the previously reported absence of Repeat 4 immunoreactivity. CONCLUSIONS: The strong conservation in intron-exon positions, gene structure, and protein sequence among mammals supports an important biological role for these signals and for the IRBP protein in vision. Low levels of aberrant IRBP mRNA in the knockout mouse are consistent with no immunologically detectable Repeat 4 protein in this mouse.