|
|
 |
 |
|
| The 4th Russia-Japan International Medical Symposium |
| The Evolution of Refractive Surgery |
Lecture Plan (See slide 2. 3)
1)Introduction
2）RK
3）PRK（indication／contraindication／complication）
4）LASIK future technology－problem．
Over history a lot of Doctors have been interested in the correction of
myopia. In the 1930's Japanese eye Dr.T・Sato tried to correct myopia by
Sato's Keratotomy－making incisions on both sides of the cornea，but his
efforts were unsuccessful．In the 1940’s，Prof.Baraquea tried to introduce
Keratomi1eusis，but it wasn't popular，because it was a diffcult procedure
and often had irregular astigmatism complications.
In the 1970's Prof．S．Fyodorov accomplished refining Keratotomy. His operation
became popular，because it was wide1y accepted as a simp1e yet safe and
effective operation.
In Japan from 1983 Dr・Okuyama of Sangubashi eye clinic started RK for the
correction of myopia and to date has performed more than 6000 operations.（cf.1980.DR.A.MOMOSE
started RK．）（see slide4，5）
To clarify the effects of RK，I selected at random 200 operation cases and
I will show you the results of the analysis．
Operation cases；
91 female 1O9 male．（See slide 6）
157 operation cases were aged 17－39，and、43 operation cases were 40 or older.The
esult of the operation is depended upon the patients original myopia. Please
look at the slides.
Mild myopia 1.0－3．0D／The post operative target is ±0.5D.
Moderate myopia 3．0－5．OD／The post operative target is ±1.0D.
High myopia 5.0－8.0D／The post operative target is to reduce the patients
myopia by 4.0D－5．OD．
Very high myopia 8.0D or more. The postoperative target is to reduce the
patients myopia by 5．OD or more．
The slide shows the correlation of refractive results，sex and age．
The optimal range of myopia preoperation for RK is from 1－5D.（See slide
7・8）
For patients with myopia of 6D or more this operation only decreases the
myopia sufficiently to allow the patient more freeedom．（See slide 9，10）
In Japan it is very common for people to have high or very high myopia.
Because of these problems with high myopia, I started to operate using Prof.S.Fyodorov
method of PRK in 1993 at Sangubashi eye clinic．（See slide ll）
|
|
Over the last 4 years I have operated on more than 1600 people with myopia
of 1-25D. 65% have been male and 35% have been female.
With myopia from 1-12D, one PRK operation gives a good result. With a myopia of 12D or
more it may be necessary to have 2 or 3 PRK operations, with an interval
of not less than 6 months. Good results can also be obtained from a combined
RK, PRK operation.(See slide 12,13)
A post operative complication which is seldomly seen is Haze（subepitherial
opacity）．Haze will disappear naturally over a period of time but treatment
will help to reduce the haze quicker．
With 0.3％ haze a reoperation using PTK is needed．
A post operative complication which is rarely seen lO／1600 is decentralization
which causes post operative astigmatism. 3 of the 10 cases were retreated
using AK.
A post operative complication which is very rarely seen （4／1600）is an ulcer
with a virus or bacterial contamination. Among these 4 cases，one case was
a 50 year old woman who was being treated with steroids for collagen disease.
3 cases were retreated using PTK.
The post operative course of PRK will start to stabilize after 1 month
and will be completely stable at about the 6 month period．（See slide 14，15，16）
My PRK hit rate for ±0．5D is 86．5％，the other 13．5％ has a hit rate 0f ±2．OD．（See slide 17） My analysis of patients with a myopia of 1.0－8.0D for the purpose of choosing RK or PRK is divided into 2 age groups the under 40 group and the over 40 group．
For patients with a myopia of 1.0－5.0D RK is good. For patients with a
myopia of 5D or more who decide on the RK operation might need to use contacts/glasses
post operation or reoperate using PRK.（See slide 18） Where as PRK is good
for patients with a myopia up to 8D，taking into account the slow recovery
time and or the possibility of haze when using PRK，Patients with a myopia
of l.0－5.0D should preferably use RK．
Under development of an automatic keratome for keratomileusis a new combination
with PRK was made， named LASIK. The purpose of LASIK is to make haze a
thing of the past，and to speed up recovery time. This is done by planing
a microscopic layer of the cornea, lifting this layer and then performing
PRK to the stromal layer，after which the flap is returned to its nomal
position. LASIK has not been completely refined，at this moment． LASIK has
a few unsavory technical defects in instrument development because of stromal
astigmatism due to the vibration of the microkeratome and uneven distribution
of laser energy due to the fixed suction ring which draws moisture to the
corneal surface．（See slide 19）
In my clinic only the following cases use LASIK；
1）myopia of 10D or more with low corrective vision．
2）patients with a high possibility of haze．
Refinement of LASIK will put it at the forefront of corneal refractive
surgery．(See slide 20） With corneal surgery dawn has just arrived and we
are waiting for the flowers of the day to begin blooming．
|
 |
|
|
|
