Table 3 of
Garcia-Ayuso, Mol Vis 2011; 17:1716-1733. Table 3 of
Garcia-Ayuso, Mol Vis 2011; 17:1716-1733.
Table 3. Differences between pigmented and albino rats after light-induced retinal degeneration.
| Pigmented | Albino |
|---|---|
| 1. Pupil dilation | |
| Necessary for phototoxicity. | Not necessary, but increases light toxicity at early periods. |
| 2. Light-sensitive “arciform area” in the dorsal retina. | |
| Blood retinal barrier breakdown almost always present in this area. | Blood retinal barrier breakdown present in this area only in 41% of the retinas. |
| Longer duration of HRP leakage (up to one month). | Shorter duration of HRP leakage (up to 7 days). |
| Retinal degeneration in this area much more severe: a very thin retina containing a few cells and the retinal nerve fiber layer remained 1 year ALE. | Photoreceptor degeneration starts and is more severe in this area, but only at early periods ALE |
| 3. Diffuse photoreceptor degeneration in areas other than the light sensitive “arciform” area. | |
| Less severe than in albino rats. | More severe than in pigmented rats. |
| 4. Axonal compression by retinal vessels. | |
| Two types of axonal compressions: a “localized” in the “arciform area” and a “diffuse” in the rest of the retina. | Only is observed the “diffuse” axonal compression |
| Starts earlier and progresses faster than in albino rats: it is observed 21 days ALE in the light sensitive “arciform” area (causes significant RGC death in the superior retina, see below) and by 4 months ALE has extended throughout the whole retina. This late “diffuse” form of axonal compression is more prevalent in the peripapillary ventral retina. | Starts later, at around 3 months and is “diffuse,” although at early times (3–9 months) is more prevalent in the dorsal retina. |
| 5. Retinal Ganglion cell death. | |
| Following the two types of the axonal compressions, there are two types of RGC loss: a “localized” form peripheral to the “arciform area” and a “diffuse” form that sometimes is sectorial (wedge-shaped sectors). | RGC death is “diffuse” although at late times ALE it is observed a sectorial (wedge-shaped sectors) loss. |
| Is more abundant in the superior retina, due to the axonal compressions in the light sensitive “arciform” area. Wedge-shaped sectors lacking RGCs can be seen 9 or more months ALE in the ventral retina. | Is diffuse and significant 6 months ALE. Wedge-shaped areas lacking RGCs can be seen at12 months ALE mainly in the ventral retina. |
| 6. Subretinal vascular complexes. | |
| Were seen always in the areas where photoreceptor degeneration was almost complete | |
| Start earlier and are more abundant: could be seen from 7 days ALE in the “arciform area,” from 3 months in the peripapillary and all throughout the ventral retina at 9 months. | First seen at around 6 months in the dorsal retina and extended throughout the retina with time ALE. |