Purpose

To characterize inner retinal damage in patients with dry age-related macular degeneration (AMD) using high-resolution spectral domain optical coherence tomography images.

Methods

Sixty eyes of 60 patients with AMD were categorized using the Age-Related Eye Disease Study (AREDS) severity scale. Spectral domain optical coherence tomography images of these patients were quantified by manually correcting the segmentation of each retinal layer, including the retinal nerve fiber layer, ganglion cell layer, and inner plexiform layer to ensure accurate delineation of layers. The mean ganglion cell complex thickness values (ganglion cell layer + inner plexiform layer + retinal nerve fiber layer) were compared with 30 eyes of 30 healthy subjects.

Results

Ninety percent of eyes (81 eyes) required manual correction of segmentation. Compared with healthy subjects, mean ganglion cell complex thicknesses significantly decreased in more advanced dry AMD eyes, and this decrease was predominantly related to a change in inner plexiform layer thickness. There was no significant difference in thickness-related measurements between milder dry AMD (AREDS-2) eyes and healthy eyes (P > 0.05).

Conclusion

In patients with dry AMD, automatic optical coherence tomography segmentation algorithms may be erroneous. As the severity of dry AMD increases, the inner plexiform layer layer becomes thinned, suggesting that transsynaptic degeneration may be occurring, as the photoreceptor layer is affected by AMD.

The authors are commenting the letter to editor regarding article entitled “Long-term remission of neovascular age-related macular degeneration with as-needed anti-vascular endothelial growth factor therapy” published in Retina Journal 2017; Doi:10.1097/IAE.0000000000001572. February 17, 2017.

Aim

To test the utility of targeted sequencing as a method of clinical molecular testing in patients diagnosed with inherited retinal degeneration (IRD).

Methods

After genetic counseling, peripheral blood was drawn from 188 probands and 36 carriers of IRD. Single gene testing was performed on each patient in a Clinical Laboratory Improvement Amendment (CLIA) certified laboratory. DNA was isolated, and all exons in the gene of interest were analyzed along with 20 base pairs of flanking intronic sequence. Genetic testing was most often performed on ABCA4, CTRP5, ELOV4, BEST1, CRB1, and PRPH2. Pathogenicity of novel sequence changes was predicted by PolyPhen2 and sorting intolerant from tolerant (SIFT).

Results

Of the 225 genetic tests performed, 150 were for recessive IRD, and 75 were for dominant IRD. A positive molecular diagnosis was made in 70 (59%) of probands with recessive IRD and 19 (26%) probands with dominant IRD. Analysis confirmed 12 (34%) of individuals as carriers of familial mutations associated with IRD. Thirty-two novel variants were identified; among these, 17 sequence changes in four genes were predicted to be possibly or probably damaging including: ABCA4 (14), BEST1 (2), PRPH2 (1), and TIMP3 (1).

Conclusions

Targeted analysis of clinically suspected genes in 225 subjects resulted in a positive molecular diagnosis in 26% of patients with dominant IRD and 59% of patients with recessive IRD. Novel damaging mutations were identified in four genes. Single gene screening is not an ideal method for diagnostic testing given the phenotypic and genetic heterogeneity among IRD cases. High-throughput sequencing of all genes associated with retinal degeneration may be more efficient for molecular diagnosis.

Purpose

To determine the efficacy of monthly (0.1 mL/4 mg) aflibercept for refractory neovascular age-related macular degeneration (wet age-related macular degeneration).

Methods

This was a retrospective interventional case series in which patients with wet age-related macular degeneration were treated with stepwise dose escalation. Nonvitrectomized patients resistant to monthly (Q4W) ranibizumab/bevacizumab were switched to 2 mg aflibercept every 8 weeks. With resistance, they were escalated to Q4W 2 mg aflibercept, then Q4W 4 mg (high dose high frequency, 4Q4W) aflibercept. Resistance was defined as ≥2 recurrences after being dry following ≥3 injections or persistent exudation on treatment of ≥5 injections.

Results

Thirty-three eyes of 28 patients were treated with 4Q4W aflibercept and followed for a mean of 16 months. A dry retina (no intraretinal or subretinal fluid) was achieved after initiating 4Q4W aflibercept treatment at a mean of 3.8 months. Central foveal thickness, maximum foveal thickness, intraretinal fluid, subretinal fluid, and retinal pigment detachment height decreased significantly at 1 month after initiating the 4Q4W aflibercept, and the morphologic therapeutic effect was sustained until the last visit. Forty-five percent of eyes had one or more lines of vision improvement. New geographic atrophy developed in 9% of eyes during follow-up. No ocular or systemic adverse events occurred after initiating 4Q4W aflibercept.

Conclusion

Intravitreal high-dose high-frequency aflibercept is an effective treatment for patients with refractory wet age-related macular degeneration.

Purpose

To determine the presenting characteristics of patients with neovascular age-related macular degeneration with long-term remission (LTR), which was defined as the absence of intraretinal/subretinal fluid, or hemorrhage, and absence of leakage on fluorescein angiography for longer than 6 months while on as-needed antivascular endothelial growth factor treatment.

Methods

The presenting characteristics of patients with LTR were compared with a control group including 32 eyes of 28 age-, gender-, and ethnicity-matched patients who did not achieve LTR.

Results

Seventy-four percent of patients in the LTR group had Type 1 choroidal neovascular membrane and 18.5% had retinal angiomatous proliferation. In the control group, 28 eyes had Type 1 choroidal neovascular membrane (87.5%), and none of the patients had retinal angiomatous proliferation; overall, there was a significant difference in lesion types between the 2 groups (P = 0.036). Eyes with LTR at presentation had significantly thinner subfoveal choroidal thickness (147 vs. 178 μm, P = 0.04). There was more intraretinal fluid and less subretinal fluid at the presentation in the remission group (59.3% intraretinal fluid and 11.1% subretinal fluid) compared with the control group (28.1% intraretinal fluid and 34.4% subretinal fluid, P = 0.03).

Conclusion

The presence of retinal angiomatous proliferation, thinner choroidal thickness, more intraretinal fluid, and less subretinal fluid at presentation were associated with LTR in patients receiving as-needed treatment for age-related macular degeneration.

Purpose

Geographic atrophy (GA) is the sequelae of macular degeneration. Automated inner retinal analysis using optical coherence tomography is flawed because segmentation software is calibrated for normal eyes. The purpose of this study is to determine whether ganglion cell layer (GCL) volume is reduced in GA using manual analysis.

Methods

Nineteen eyes with subfoveal GA and 22 controls were selected for morphometric analyses. Heidelberg scanning laser ophthalmoscope optical coherence tomography images of the optic nerve and macula were obtained, and the Viewing Module was used to manually calibrate retinal layer segmentation. Retinal layer volumes in the central 3-mm and surrounding 6-mm diameter were measured. Linear mixed models were used for statistics.

Results

The GCL volume in the central 3 mm of the macula is less (P = 0.003), and the retinal nerve fiber layer volume is more (P = 0.02) in patients with GA when compared with controls. Ganglion cell layer volume positively correlated with outer nuclear layer volume (P = 0.020).

Conclusion

The patients with geographic atrophy have a small significant loss of the GCL. Ganglion cell death may precede axonal loss, and increased macular retinal nerve fiber layer volumes are not indicative of GCL volume. Residual ganglion cell stimulation by interneurons may enable vision in patients with GA.