If the reconstruction is poorly performed, it may result in a high rate of recurrent cholesteatoma. Preservation of the ear canal wall. If poorly performed, it may result in a high rate of both residual and recurrent cholesteatoma. Reconstruction of the chain of hearing bones using a passive middle ear implant.Clearly, preservation and restoration of ear function at the same time as total removal of cholesteatoma requires a high level of surgical expertise. Endoscopic surgery
Traditionally, ear surgery has been performed using the surgical microscope. The direct line of view dictated by that approach necessitates using the  mastoid as the access port to the middle ear. It has long been recognized that failure in cholesteatoma surgery occurs in some of the out of view spaces of the tympanic cavity like the sinus tympani and facial recess that are out of view using the traditional microscopic technique. More recently, the endoscope has been increasingly utilized in the surgical management of cholesteatoma in one of two ways:

Using the endoscope as an ancillary instrument to the microscope when trying to visualize areas that are hidden from the microscope such as the sinus tympani. This work was pioneered by Professor Thomassin. Using the endoscope as the main surgical instrument through the ear canal, or whats called:  Endoscopic Ear Surgery, pioneered by Professor Tarabichi.There are multiple advantages for the use of the endoscope in cholesteatoma surgery:

The endoscope wide angle of view and the ability to "see around the corner".
Xerophthalmia from hypovitaminosis A is specifically due to lack of the hormone-like vitamin A metabolite retinoic acid, since (along with certain growth-stunting effects) the condition can be reversed in vitamin A deficient rats by retinoic acid supplementation (however the retinal damage continues). Since retinoic acid cannot be reduced to retinal or retinol, these effects on the cornea must be specific to retinoic acid. This is in keeping with retinoic acids known requirement for good health in epithelial cells, such as those in the cornea. Cause
The condition is not congenital and develops over the course of a few months as the lacrimal glands fail to produce tears. Other conditions involved in the progression already stated include the appearance of Bitots spots, which are clumps of keratin debris that build up inside the conjunctiva and night blindness, which precedes corneal ulceration and total blindness. Classification
World Health Organization classified xerophthalmia into following stages:
XN-Night blindness
X1A-Conjunctival xerosis
X1B-Bitot spots
X2-Corneal xerosis
X3A-Corneal ulceration/keratomalacia, involving less than one-third of the cornea
X3B-Corneal ulceration/keratomalacia, involving more than one-third of the cornea
XS-Corneal scar due to xerophthalmia
XF-Xerophthalmic fundus

Prevention
Prophylaxis consists of periodic administration of Vitamin A supplements.