Table 2 Previous SRH models.

Mouse³⁴

Injections via transscleral route with a 33G needle 1.6 µl autologous blood (from tail vein);

survival times 6 h to 10 days

Increased expression of inflammatory cytokines, chemokines and adhesion molecules; microglial migration, increased density; effects of minocycline

Use of metal needle, lower biocompatibility and larger tip size

Rat^35–37

heparinized and diluted blood (one part blood to ten parts saline) injected subretinally

The retina overlying the hemorrhage became intensely degenerated over a period of months

Heparin is an anticoagulant; clotting process differs from fresh blood injections

Rabbit³⁸

0.1 ml fresh blood from ear;

specially constructed 30G needle tip encased in a 22G spinal needle;

clot prevention 0.03 cc of air in the needle tip (also injected in the subretinal space);

survival times:1 h to 28 days

Signs of degeneration after 1 day in the outer retinal layer

Use of plus air bubble, can make retinal detachment worse

Rabbit³⁹

0.1 ml fresh blood from ear;

30G needle;

Clot prevention: air bubble

Intravitreal injection of tPA 1 day after subretinal injection of blood in rabbits facilitated more rapid lysis of the clotted blood, however, retinal damage was not prevented

Use of plus air bubble, can make retinal detachment worse

Rabbit⁴⁰

100 µl autologous blood from ear vein in a nasal juxtapapillary location along the myelinated streak;

An angled 1-inch, 30-gauge needle was introduced transsclerally 3–4 mm posterior to the limbus

Photoreceptor toxicity caused by SRH occurs at least in part by apoptosis and is associated with iron migration to the photoreceptor layer

Use of metal needle

Cat⁴¹

the tip of a 20-gauge surgical knife or a 25-gauge needle was passed transsclerally into the bleb and then withdrawn, allowing choroidal blood to extend under the retina into the area centralis;

Lesions were observed 25 min to 14 days

In 6 of 9 clots more than 1 h old, fibrin was associated with tearing of sheets of photoreceptor inner and outer segments. Later degeneration progressed to involve all retinal layers overlying the densest areas of fibrin in the clots; hemorrhages into subretinal blebs containing tPA did not form fibrin strands or cause photoreceptor tearing

Use of metal needle

Cat⁴²

the tapetal or nasal retina with a neodymium: YAG (Nd: YAG) laser focused through a preformed retinal bleb; 2–25 laser shots (mean, 14) at between 20 and 25 mJ were fired until one created a large subretinal hemorrhage

Removing experimental SRHs within 7 days of their occurrence with the assistance of rt-PA and an ultra-microsurgical approach may reduce outer retinal degeneration

Laser due to heat and tissue absorption