Intrastromal Injection of China Painting Ink in Corneas of Male Rabbits: Clinical and Histological Study

Abstract

Background. Many patients with corneal opacity or complicated cataract in blind eye ask for cosmoses. In this study we tried to investigate the staining of corneas of male rabbits by Rotring China painting ink and to study the histological changes. Method. 10 eyes of 10 male Baladi Egyptian rabbits were injected (0.1 mL) intrastromally in the cornea by the use of China painting ink (Rotring Tinta China) through insulin syringe (27-gauge needle) by single injection; clinical follow-up is for 6 months and lastly the rabbits were scarified and the stained eyes were enucleated for histological analysis. Results. Clinically the stain was stable in color and distribution in corneas with no major complications. Histological results of the stained rabbit corneas showed blackish pigmentation in the corneal stroma without any inflammatory cellular infiltration. Some fibroblast cells had pigment granules in their cytoplasm in the adjacent layers. Conclusion. Corneal staining by China painting ink is effective and safe in staining of male rabbits cornea; however further study in human corneas with longer follow-up period is advisable.

Effect of intraoperative optical coherence tomography on anatomic and cosmetic results of intrastromal tattooing

“…Despite establishing the long-term safety of rotring ink in animal and human studies, its ocular or systemic toxicity cannot be ruled out and every attempt should be made to prevent its inadvertent intraocular entry. [ 11 16 ] Lack of intraoperative perforation in any of our patient could be mainly attributed to the use of i-OCT during lamellar dissection. However, even previous studies on intrastromal tattooing conducted without the aid of i-OCT have not reported any perforation till date.…”

“…The site of tattooing was marked using disposable trephines, especially in cases of localized tattooing. [ 16 ] A 4 mm partial thickness clear corneal incision aimed at 50% depth (the depth was decided based on prior studies) was created 1 mm away from the limbus with a microcrescent knife (Sharpoint, Surgical Specialties Corporation, Wyomissing, PA; USA). This was appreciated on i-OCT as a hyporeflective pocket surrounded by hyperreflective stromal layers on either side.…”

“…[ 5 ] Although the exact composition of this dyeing material remains elusive, the presence of 85% water and 10% water-insoluble carbon compounds makes it biocompatible and resistant to chemical changes with sterilization. [ 3 6 11 15 16 ] Numerous techniques described to introduce carbon-containing coloring agent into the corneal stroma include multiple micropunctures guided by needle, manual dissection, microkeratome-assisted flap creation, or lamellar keratectomy. [ 7 11 12 13 14 17 18 19 ] However, all these techniques have difficulty in accurately predicting the depth traversed by the needle or the blade due to their blind nature and can result in inadvertent damage to Bowman's membrane or corneal perforation.…”

Outcomes of Corneal Tattooing by Rotring Painting Ink in Disfiguring Corneal Opacities

“…Several studies have concluded that corneal tattooing using china ink is considered durable with permanent effect as it is engulfed by keratocytes [ 8 , 12 ] or endocytosed by corneal fibroblasts [ 17 ]. Some other theories proposed stability due to the fact that the cornea has no lymphatics, and thus, there is no diffusion or dispersion [ 18 ].…”

“…The Rotring painting ink (Rotring Ink, Hamburg, Germany) (also known as China ink) was packed in a sterile glass infusion bottle for 20 minutes in a steam autoclave at 121°C. One of the authors (AHA) has previously demonstrated the safety and efficacy of using the same type of Rotring painting ink used in our study on male rabbits [ 12 ]. The stain color used was the black for all eyes.…”