Indian Journal of Ophthalmology

COMMENTARY
Year
: 2019  |  Volume : 67  |  Issue : 5  |  Page : 610--611

Commentary: In vivo confocal microscopy in iridocorneal endothelial syndrome


Vineet Ratra 
 Department of Comprehensive Ophthalmology (Special Interest Glaucoma and Cataract), Medical Research Foundation, Navasuja Sankara Nethralaya, Chennai, Tamil Nadu, India

Correspondence Address:
Dr. Vineet Ratra
Department of Comprehensive Ophthalmology (Special Interest Glaucoma and Cataract), Medical Research Foundation, Navasuja Sankara Nethralaya, 73, Venkatakrishna Road, RA Puram, Mandaveli, Chennai - 600 028, Tamil Nadu
India




How to cite this article:
Ratra V. Commentary: In vivo confocal microscopy in iridocorneal endothelial syndrome.Indian J Ophthalmol 2019;67:610-611


How to cite this URL:
Ratra V. Commentary: In vivo confocal microscopy in iridocorneal endothelial syndrome. Indian J Ophthalmol [serial online] 2019 [cited 2019 Aug 21 ];67:610-611
Available from: http://www.ijo.in/text.asp?2019/67/5/610/256669


Full Text



The iridocorneal endothelial syndrome (ICE) consists of a group of ocular disorders in which there is proliferation of corneal endothelial cells which migrate toward the iridocorneal angle and onto the iris. The proliferation of these cells predisposes to corneal edema and decompensation, and further proliferation invariably leads to glaucoma.[1] It includes Chandler's syndrome, progressive essential iris atrophy, and Cogan–Reese syndrome, a spectrum of diseases characterized by corneal endothelial abnormality, progressive iris atrophy, anterior synechiae, and secondary glaucoma.[1] Although clinical presentation is characteristic, these disorders have been confused with iris melanoma, neurofibromatosis, and oculodermal melanocytosis, among others.[2] The morphological changes in the endothelium observed by confocal microscopy are critical for diagnosis of ICE syndrome.

In vivo confocal microscopy (IVCM) is increasingly being used to study complex corneal and anterior segment pathologies. It is considered a useful adjunct diagnostic tool for ICE syndrome.[3] It has distinct advantages over specular microscopy. Specular microscopy shows the ICE cells with typical dark-light reversal pattern. The cell surface is dark instead of light, with a central, hyperreflective nucleus. The intercellular junctions are light instead of dark. In specular microscopy, it is difficult to obtain images in thickened edematous cornea. Specular microscopy provides images of only the endothelial cell layer. In contrast, IVCM can analyze cells at all corneal layers and provide description of the microstructural changes in pathological conditions.[3] Corneal thickening does not affect IVCM. In addition, it is noninvasive and has superior resolution with high-image contrast. Confocal microscopy is therefore a useful tool with much potential in diagnosing ICE syndrome and especially of great value in cases with corneal edema.

The epitheloid-like ICE cells can be of regular size and shape with a pattern similar to normal endothelial cells, however, with loss of normal hexagonality displaying prominent uniform “cobblestone-like” nuclei in the central area. They can also be more irregular in size and shape, with hyperreflective diversely shaped nuclei adjacent to the boundaries of the cells. Different patterns of distribution of the ICE cells have been noted. The endothelium can be completely or partially replaced by the ICE cells or they can be scattered in clusters among normal endothelium.[4]

In this issue, Malhotra, et al.[5] describe two types of ICE cells and their predilection for gender preference. They found that the smaller ICE cells were more frequently associated with elevated intraocular pressure. Grupcheva et al.[6] also remarked that the smaller ICE cells are associated with elevated intraocular pressure. They suggested that the differences, especially the amplitude and duration of the intraocular pressure (IOP) increase, correlate with the duration of the disease. Acute elevated IOP has been shown to cause significant loss of endothelial cells. Chronic elevated IOP could potentially compromise endothelial function. The reported prevalence of glaucoma in eyes with ICE syndrome ranges from 46% to 82%.[1] Laganowski et al.[7] found glaucoma most commonly in the variants in which abnormal cells involved the entire posterior corneal surface in a disseminated manner. Thus, IVCM can be useful for predicting clinical prognosis.

Apart from the endothelial cells, IVCM has also shown changes in other layers of the cornea in eyes with ICE syndrome which include varying degrees of changes in the corneal stroma, pseudoprominent corneal nerves, and bizarre syncytia of keratocytes. Even in the clinically uninvolved eye, IVCM could demonstrate subclinical endothelial changes including increased pleomorphism and a relatively high coefficient of cell area variations.[1] Thus, the superior resolution of IVCM, its ability to analyze all cellular layers of the cornea even in the presence of edema and scar, and its static and dynamic properties make confocal microscopy an invaluable test to differentiate different diseases of the cornea. It provides a tissue-based diagnosis in cases of vague clinical presentations.

References

1Silva L, Najafi A, Suwan Y, Teekhasaenee C, Ritch R. The iridocorneal endothelial syndrome. Surv Ophthalmol 2018;63:665-76.
2Shields CL, Shields MV, Viloria V, Pearlstein H, Say EA, Shields JA. Iridocorneal endothelial syndrome masquerading as iris melanoma in 71 cases. Arch Ophthalmol 2011;129:1023-9.
3Le QH, Sun XH, Xu JJ. In-vivo confocal microscopy of iridocorneal endothelial syndrome. Int Ophthalmol 2009;29:11-8.
4Malhotra C, Pandav SS, Gupta A, Jain AK. Phenotypic heterogeneity of corneal endothelium in iridocorneal endothelial syndrome by in vivo confocal microscopy. Cornea 2014;33:634-7.
5Malhotra C, Seth NG, Pandav SS, Jain AK, Kaushik S, Gupta A, et al. Iridocorneal endothelial syndrome: Evaluation of patient demographics and endothelial morphology by in vivo confocal microscopy in an Indian cohort. Indian J Ophthalmol 2019;67:604-10.
6Grupcheva CN, McGhee CN, Dean S, Craig JP.In vivo confocal microscopic characteristics of iridocorneal endothelial syndrome. Clin Exp Ophthalmol 2004;32:275-83.
7Laganowski HC, Kerr Muir MG, Hitchings RA. Glaucoma and the iridocorneal endothelial syndrome. Arch Ophthalmol 1992;110:346-50.