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Broken Eyes · **Joined:** Sat Nov 26, 2005 7:23 am **Posts:** 3109

In vivo confocal microscopy of the human cornea

I Jalbert, F Stapleton, E Papas, D F Sweeney, and M Coroneo
Br J Ophthalmol. 2003 February; 87(2): 225–236.

The full text of this article is available online at:
http://www.pubmedcentral.nih.gov/articl ... id=1771516

Broken Eyes · **Joined:** Sat Nov 26, 2005 7:23 am **Posts:** 3109

Subbasal Nerve Regeneration After LASEK Measured by Confocal Microscopy
Journal of Refractive Surgery Vol. 23 No. 7 September 2007
Taym Darwish, PhD, MSc; Arun Brahma, MD; Nathan Efron, PhD, DSc; Clare O’Donnell, PhD, MCOptom, FAAO

Excerpt from full text:

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CONFOCAL MICROSCOPY

Confocal microscopy was performed with a Tomey ConfoScan P4 (Tomey Corp, Nagoya, Japan). The 40x/0.75NA objective of the ConfoScan was disinfected with a swab saturated with isopropyl alcohol BP 70% v/v (Seton Healthcare Group, Oldham, England), and the cornea was anesthetized with 1 drop of benoxinate hydrochloride 0.4% (Chauvin Pharmaceuticals Ltd, London, United Kingdom). A drop of liquid gel (Viscotears Liquid Gel; Novartis, Frimley, United Kingdom) was applied to the tip of the objective. Patients then were instructed to place their chin and forehead onto the rests and look straight ahead. The lens was moved toward the central cornea until it contacted the gel. When the epithelium was seen on the monitor, the recording button was pressed. The lens was moved forward to image all corneal layers and then moved backward and forward until several scans of the entire depth of the cornea were recorded.

Bill · **Joined:** Thu Nov 24, 2005 3:06 pm **Posts:** 306

Not peer-reviewed:

http://www.escrs.org/PUBLICATIONS/EUROT ... ewayto.pdf

On the way to in-vivo histology

Excerpts:

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CONFOCAL in-vivo microscopy reveals corneal detail on the cellular level, enabling researchers to discover new features of corneal innervation and learn more about the cells that play a pivotal role in corneal mmunity.This offers the potential to help tackle some of the complications plaguing refractive surgery today, report researchers.

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Still deeper into the cornea, at roughly 50μm, this technology illuminates the nerve cell layer, as never before seen.While scientists once believed that corneal nerves grew radially inward toward the corneal centre, investigations with the RCM revealed that they grow in a spiral-like fashion. Knowing about the anatomy of corneal nerves and their growth pattern enables us to study the changes seen with innervation deficits, like in herpetic keratitis and after trigeminal nerve damage. It also provides refractive surgeons with better information about the nerve plexus they are disrupting and more clues on how nerves might regenerate after surgery, Dr Guthoff explained.

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In LASIK patients, it shows the precise events at the surgical interface, including cell growth, cell differentiation at the interface, and interface fibrosis. Dr Guthoff suggested that femtosecond laser ablation sites be examined with this technology to determine the actual effect of the laser in the cornea.

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The technique relies on a confocal image, which Dr Guthoff compared to the image from the slit lamp, which eye doctors knew from everyday practice. As with slit-lamp imaging, the investigator precisely focuses the confocal microscope on a certain area, blocking out all other light, to concentrate on the illuminated area, only with the advantage of 800-fold image magnification. The eye comes into direct contact with the machine, using anaesthesia, artificial tears and a small PMMA cap, which covers the objective and helps stabilise the image seen through the microscope.A newer cap design features a thin groove along the contact side, which helps reduce the applanation pressure and allows investigators to examine the corneal epithelium without side effects.

Broken Eyes · **Joined:** Sat Nov 26, 2005 7:23 am **Posts:** 3109

Curr Opin Ophthalmol. 2006 Aug;17(4):380-8.

How has confocal microscopy helped us in refractive surgery?

Kaufman SC, Kaufman HE.
Henry Ford Health System: Ophthalmology, Troy, Michigan 48083, USA. svkman@yahoo.com

PURPOSE OF REVIEW: To summarize the known uses of in-vivo confocal microscopy in refractive surgery, highlighting the current developments in the field.

RECENT FINDINGS: Examination of the cornea after laser in-situ keratomileusis demonstrated that the keratocyte density within the laser in-situ keratomileusis flap and anterior residual corneal bed continued to decline during the entire 3-year period of the study. The progressive loss of keratocytes in the flap and anterior portion of the residual corneal bed could have long-term implications in terms of corneal stability, refractive stability and cellular integrity after laser in-situ keratomileusis. Additional studies showed that the density of sub-basal nerves decreased by 90% 1 month after laser in-situ keratomileusis. At some point between 3 and 6 months after laser in-situ keratomileusis, the sub-basal nerves began to recover and by 2 years they had reached approximately 50% of their original preoperative density. Analysis of sub-basal nerve density after photorefractive keratectomy reported that the nerve density completely recovered to preoperative levels by 2 years. Other confocal microscopic studies demonstrated that the microscope can detect infectious organisms in vivo, without stains or dyes.

SUMMARY: The confocal microscope is a unique diagnostic instrument that can be used to evaluate corneal healing, long-term stability and to assess complications after refractive surgery. The ability of the device to view in-vivo cellular detail, microorganisms, inflammatory cells, epitheliod cells, fibrosis and measure the postoperative thickness of the residual corneal bed after laser in-situ keratomileusis, in a noninvasive manner, highlights the unique capabilities of this instrument.

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