Indian Journal of Ophthalmology

EDITORIAL
Year
: 1990  |  Volume : 38  |  Issue : 3  |  Page : 102-

Radial keratotomy-A decade's perspective


Gullapalli N Rao 
 L.V. Prasad Eye Institute Hyderabad, India

Correspondence Address:
Gullapalli N Rao
L.V. Prasad Eye Institute Hyderabad
India




How to cite this article:
Rao GN. Radial keratotomy-A decade's perspective.Indian J Ophthalmol 1990;38:102-102


How to cite this URL:
Rao GN. Radial keratotomy-A decade's perspective. Indian J Ophthalmol [serial online] 1990 [cited 2024 Mar 29 ];38:102-102
Available from: https://journals.lww.com/ijo/pages/default.aspx/text.asp?1990/38/3/102/24527


Full Text

The quality of life is the major concern of medical science, as we approach the turn of the century. Oph�thalmology for its part had embarked upon the tasks of improving the quality of vision. The optical correction of visual problems had traditionally been accomplished with glasses. Contact lenses followed and more recently surgical procedures for the correction of visual problems have been introduced.

The procedure of radial keratotomy introduced for the correction of myopia had been a subject of considerable discussion during the past decade. While the origin of this idea dates back to the 19th century, Fyodorov popularised the-technique in the recent past. Significant improvements have evolved through the efforts of several American investigators. The underlying principle is to flatten the central cornea by making radial incisions in the cornea outside the central optical zone.

From the experience of several investigators around the world the conclusion is that this procedure is effective for the correction of lower degrees of myopia, namely, upto 6 diopters. Factors that are known to determine this success include the age of the patient, depth of in�cisions, number of incisions and size of the optical zone. The mechanics of corneal healing, however, plays a crucial role and ultimately determines the efficacy of the procedure. Technical improvements in the surgical in�strumentation such as diamond knives for better in�cisions, ultrasonic pachymeters for the accurate measurement of the corneal thickness and the employ�ment of operating microscope have together contributed to a higher rate of success.

As with any modality of treatment, radial keratotomy also is fraught with complications ranging from symptoms such as fluctuating vision and glare, to sight threatening problems like cataract and endophthalmitis. While, for�tunately, the incidence of the latter two are negligible, the ophthalmoligist should be cognizant of this potential. Any complication with this procedure becomes more significant because the procedure is performed on a structurally normal eye with normal visual potential with appropriate optical correction. The moral issues of ex�posing such eyes to surgery will remain debatable.

This brings in the issue of proper patient selection. This is not only in terms of the degree of myopia but also the personality of the patient. A motivated patient with realis�tic expectations, only should be considered. The medi�cal contraindications should not be overlooked. Factors such as patient's age, stability of refractive error, and presence of pathologic processes in the eye should be given due consideration.

Another important factor that adds to success is proper training of the ophthalmologist and his access to neces�sary infrastructure. Exposure to microsurgery, in�frastructure required for radial keratotomy and meticulous surgical technique are critical. Operating microscope, electronic pachymeter, diamond knife and other surgical instruments are basic requirements to achieve a high success rate.

Any procedure that is new should be subjected to scien�tific scrutiny and evaluated on the basis of safety, stability, predictability and long term results.

In terms of safety, radial keratotomy is safe, provided the basic guidelines are adopted. The complications of an irreversible nature are few.

Stability of its effect remains a question. Recent obser�vations, as also seen in this issue from the PERK study, suggest that the effect of this procedure is not stable. Almost a third of the patients seem to present continuing shift in refraction.

Results from all studies indicate that predictability remains a major concern of radial keratotomy, while some predictors are identified, the puzzle remains un�solved.

Longterm effects of this surgical intervention on the cornea remain unknown. The corneal endothelium is shown to demonstrate progressive changes. Whether these changes progress to result in adverse clinical phenomenon remains to be seen. The effect of near full thickness incisions on corneal endothelium as well as corneal healing need to be further elucidated.

The newer frontiers of laser technology and biological modulation of wound healing offer promise for solving some of these problems. Radial keratotomy with the excimer laser offers greater precision of incisions and employment of growth factors that augment the strength of wounds may make the future of this procedure brighter.