Abstract
Cataract surgery in its simplest form is at least 4000 years old. Couching for cataract was the earliest method at about 2000 BC, and even then was evidently practiced in the Tigris / Euphrates area, as well as India and Japan. The earliest records are from The Bible and The Red Sea Scrolls as well as early Hindu records of Susruta’s time. Records exist from 400 BC (in Hippocrates time) and from 10 AD and 200 AD (from Roman records), as well as later Arabic references, but there is little evidence in Europe during the middle or dark ages.
The premodern era dates from Daviel’s original extra-capsular
surgery in 1748 leading to the advances of the late nineteenth
and twentieth centuries via intra-capsular surgery, implant
lens prostheses, and the present small incision phacoemulsification
surgery.
Keywords
Cataract surgery history, intra-ocular lens, extra-capsular, intra-capsular.
The surgery of cataract in antiquity
The history of intervention for cataract, though shrouded
in the mists of time, is as ancient as any surgical discipline.
Before 2000 BC, the code of Hamurabi is unspecific on surgery,
but it is possible that the Babylonians used lens depression
for cataract by forcing the lens from its zonular attachments
by digital pressure on the globe.1
Japanese surgeons, about 2000 BC or before, had access to
relatively advanced metallurgy and used sharp needle knives
and fine gold canulae to suck out hypermature (liquefied)
cataracts.2 There are early
Hindu references to Couching surgery for cataract by Susruta,
using incision and instruments pressing on the lens itself
in order to displace it from the pupil into the vitreous gel.
If the lens capsule remained intact (intracapsular couching)
this approach could be quite successful, giving brighter albeit
unfocused vision. In cases where the capsule was ruptured
(extra capsular couching), severe uveitis would later usually
destroy the eye, and there would be the ever-present hazard
of severe infection (endophthalmitis). It is uncertain whether
Susruta lived before or after Alexander in India (339 BC),
and whether he influenced (or was influenced by) the Aesculapian
period of Greek medicine of which Hippocrates of Cos (460-377
BC) is best recognised. These Greek surgeons undoubtedly used
couching and much of their knowledge was passed to Alexandria
and later to Rome, but the written records of Alexandria were
lost with the destruction of the great library. However, Roman
records do exist, particularly the Greek ophthalmological
terminology, which the Romans largely adopted and which persists
to the present day.
The earliest written description of (self) couching is in
The Apochrypha of the Bible, in the book of Tobbit3,
fragments of which persist in the Dead Sea Scrolls4,
and can be dated very close to 612 BC, the fall of Nineveh
within Tobbit's lifetime. Tobbit attributed his progressive
blindness when he was 62 years old, to sleeping under the
wall of his courtyard in Nineveh; "And mine eyes being open,
the sparrows muted warm dung into them, and a whiteness came
into mine eyes." The 'whiteness' description is very reminiscent
of 'chitta motia' or the white blindness = cataract in modern
Urdu and Hindu. Tobbit's blindness was not immediate. When
he was about 70, his son Tobias returned from a long journey
from Rhages in Media, to collect a debt. During this journey,
a fish leaped from the river Tigris and almost swallowed his
foot. Tobias and his friend ate the fish, but retained the
heart, liver and the gall [bladder], being instructed "...to
anoint a man that hath the whiteness of the eyes and he shall
be healed." At this point the story diverges to Sarah, a woman
whose seven previous husbands had died on their wedding nights.
(This account is well worth a visit to The Book). Tobias survived
his marriage to Sarah, and on reaching home 'Anna the wife
of Tobbit saw him from afar.' Tobbit, who was by now blind,
stumbled at the door, but his son Tobias took hold of his
father and "...Strake of the gall on his fathers eyes, saying
'Be of good hope my father.' And when his eyes began to smart,
he rubbed them; And the whiteness piled away from the corners
of his eyes: and when he saw his son he fell upon his neck"
(Figure 1). This
is an account of self couching by rubbing [hard] in response
to severe irritation of the gall (Bile), producing an immediate
return of vision. Bile is highly irritant but also contains
detergents and enzymes (i.e. chymotrypsin) which would weaken
the zonules5.
In Rome, Celsus (25BC-50AD)6
practiced couching by slim flat needles. Pliny (23-79 AD)
recorded that Hyoscyamus (Henbane, an atropine like herb)
was used to dilate the pupil for couching7.
Galen (131-210AD)8 wrote that
evacuation of the lens was attempted by suction. His description
of preparing [the theatre] for surgery bears resemblance to
current practice; clearly there was a good comprehension of
'contagion'.
It is remarkable that these operations on the lens were
done with highly inaccurate knowledge of the anatomical position
and function of the lens, which was thought to be the seeing
tissue of the eye, the lens being displaced by couching to
allow 'sufficio' (or a humor) from the locus vacuus, (the
combined anterior and posterior chambers) to perfuse back
to the (supposedly) hollow optic nerve.8
With the fall of Rome, much of this knowledge was lost in
the Europe of the dark ages, but it was transported into the
Arab world by the migrations of the origins of Islam, so that
Ammar Ben Ali was able to describe lens aspirations by fine
glass tubes11. From this Arab
route, later translations were made back into Latin, Provencal,
Old French and English. Couching practice was taken to Africa,
where quite recently it was still being done by a stick or
thorn. In England, Chevalier Taylor, an itinerant (charlatan)
practitioner, couched for cataract and moved on before the
frequent uveitis destroyed the eye. George Frederick Handel
was blinded in one eye in this way.
The beginning of enlightenment
Fabricus located the true position of the lens and established
the use of convex spectacles after couching for cataract.9
The first true extra-capsular cataract surgery was by Daviel
in Paris in 1748, using an inferior incision by needle knife,
or a keratome and curved scissors, to access and remove the
lens nucleus. Inferior section was a natural operative choice
for a patient seated and held by helpers; Bell's phenomenon
would naturally turn the eyes up; the gush of aqueous irrigating
both lens cortex and bacteria outwards. Modern corneal scissors
are remarkably similar to Daviel's. Triangular keratomes with
cutting leading edges were also used.
Von Graefe (1860) designed narrow bladed knives that were
exceptionally sharp and long thereby permitting superior incisions
(Figure 2). He
also introduced iridectomy, subsequently shown to avoid pupil
block caused by synechiae (Occlusio pupillae).
Belladonna Atropa (Deadly nightshade) was used to dilate the pupil from 1796 giving better visualisation and post operative control of synechiae. Atropine was synthesised from this alkaloid in 1831 and cocaine anaesthesia (an improvement on laudanum) was used first in 1884, both topically and by injection.
These pharmacological advances were accompanied by improvements
in illumination, first by spot projecting lamps often with
blue or other filters to show up capsule & lens cortex.
Magnifying near vision glasses and telescopic loupe glasses
gave support to older emetropic and hypermetropic surgeons,
allowing a better microscopic view of the operative field.
Improved manufacturing and metallurgy led to the development
of better steel instruments during the 19th and 20th centuries.
Von Graefe's knife was widely used until the 1970's, when
it began to be displaced by 'ab externo' (sub conjunctival)
incision, using scalpel and scissors, or razor blade fragments,
and later by small micro blades of diamond or ruby. The Graefe
knife required considerable dexterity and skill but could
produce a near limbal section and conjunctival flap in one
sweep.”10 Graefe section is
for artists; knife and scissors are for mere mortal surgeons”
(Gunnar Swegmark of Sweden). The conjunctival flap improved
the stability of the upper limbal wound at a time when suturing
was rare. (i.e. the first half of the 20th century). These
weak wounds were aided by immobilising patients between sandbags
or pillows, and restricting them to soft non constipating
food for 10 days post op.! Occasionally iris prolapse in the
wound required theatre restabilisation of the incision after
iridectomy, and there still remained the risk of endophthalmitis
and later sympathetic ophthalmitis. Even in the early 1960's
not all surgeons sutured cataract wounds. The early sutures
of Kalt silk (6-0 gauge, approx. 150µ) were crude by present
standards; sometimes 1 to 3 sutures were placed under the
conjunctival flap; being irritant, they were removed by the
nurse at 10-20 days. In the 1950's single strand virgin silk
(50µ) came into use and would usually shed itself at 3 weeks.
Fortunately, the Cartella shield, a shell of aluminium or
card made to rest on the nose bridge, forehead and cheek (with
a firm eye pad underneath) gave some protection to the fragile
wounds from the patients’ curiosity and inopportune investigating
finger.
Techniques
The Extracapsular technique was predominant from 1749 to the early 1900s. The anterior lens capsule was opened, either by toothed forceps (Arruga) or by being incorporated in a single action Graefe knife sweep through the cornea and lens capsule. Saline irrigation and pressure on the inferior cornea was used to express the lens nucleus via the large wound. The soft cortex was then flushed out from the pupillary plane using a silver canula and rubber bulb syringe. Atropine eyedrops were used pre operatively in order to improve visualisation, and post operatively to avoid synechiae to the iris or capsule remnants. The synthesis of cortisone (1950) and antibiotics reduced the risks of iridocyclitis and infection. The strong possibility of pupil block, iris bombé, and subsequent glaucoma was largely overcome by iridectomy (Basal & later Peripheral: Moorens, 1864.), which later became a standard part of all cataract procedures before the wound was closed with the conjunctival flap and the fibrin of the natural wound healing process. By the mid 20th century, more advanced surgeons were closing the wound with one to three virgin silk sutures, swaged onto atraumatic hollow tailed needles that greatly reduced suture reactivity. Extra capsular surgery continued for patients under the age of 40, because of their stronger zonules, even after the introduction of intra-capsular extraction.
The intra-capsular technique was introduced in 1880
(Smith). After section and iridectomy, and with the pupil
dilated, the lower part of the anterior capsule was grasped
by forceps (and by a variety of rocking manoeuvres the zonules
were weakened and broken from the ciliary muscle (usually
without rupture of the capsule)10.
The lens was then delivered upside down by an action known
as tumbling (Figure
3). Excess pulling could cause either capsule rupture
or vacuum at the vitreous face, which might rupture and cause
macular oedema and subsequent retinal detachment. In the Kirby
technique (1955)11, the capsule
was grasped near its upper pole and the lens slid out after
breaking the upper zonules. Barraquer introduced Zonulysin
(i.e. alpha chymotrypsin, a digestive proteolytic enzyme of
bovine origin)12, which could
be injected into the posterior chamber before either method,
as an aid to easier and safer lens delivery. Miniature suction
devices (Erisophakes) were an alternative method. Krawicz
(1963)13 used a silver rod
conducting cold from solid CO2 in a syringe 'cryoextractor'
in order to make adhesion to the lens more reliable. This
technique was refined by Amoils (1964)14,
who used the Joule Thomson effect to cool the cryoprobe17
which could then be reheated electrically, or by warm gas
to release the probe if the resulting iceball also adhered
to iris (Figure 4).
Post-operative refraction was usually carried out at 10-14 weeks allowing
for healing / astigmatic changes to stabilise. The typical
final refraction for previous emetropes was of the order of
+10.00/+3.00 x 180. While in most cases patients had good
acuity the lenses were heavy, had spherical aberration, and
had a spectacle magnification of 25%. This magnification could
cause diplopia, and was a problem when there was a long time
gap between surgery on the two eyes. Contact lenses reduced
this image disparity to 7%, but were not always satisfactory
in the aged. The highly curved optics of aphakic glasses also
gave rise to the 'Jack in the box' phenomenon, i.e. objects
crossing the field of view would be unfocused outside the
lens edge, would disappear in the refractive scotoma only
to appear suddenly magnified in the central field (Figure
5). Attempts to reduce these optical defects included
lenticular lenses with a small central optic with a plano
outer zone. 'High drop' lenses, of aspheric design had moderate
success in the late 1960's.
In 1949 Sir Harold Ridley14
observed that plexiglass (methylmethacrylate ) fragments from
spitfire canopies were inert in the injured eyes of pilots.
From that observation he designed the first ever perspex intra-ocular
lens, which he placed on the posterior lens capsule after
extracapsular removal of the natural lens. Ridley was an exceptional
surgeon, and achieved success in this approach, although not
all surgeons could reproduce his results with the heavy prototype.
Others later capitalised on this material to make lighter
anterior chamber lenses (e.g. Strampelli, Choyce) (Figure
6). D.P. Choyce,15 a former
assistant to Ridley, carried this idea through a period of
great hostility, being joined by Binkhost, and Boberg Ans
in Europe, and Tennant in the USA. Choyce's Mark IX was moderately
successful, having 4 rigid feet in the angle of the anterior
chamber. This lens occasionally caused attrition of the corneal
endothelium and decompensation oedema. Danheim's lens, with
flexible nylon loop supports, was particularly prone to this
complication.
At the same time surgical techniques were improving with
10-0 nylon sutures (12m) on atraumatic
needles. In the early 1960s16
Binkhorst, and Feoderev made implants to clip onto the iris
sphincter, sometimes aided by pilocarpine miosis. Initial
results were good though the technique was difficult (Figure
7). Typical post-operative refractions might be plano/+2.50
x 180, the astigmatism resulting from the large wound. It
was at this time that many UK surgeons began to feel that
implants were a 'respectable' method of treatment. Problems
still existed: pupil dilatation allowed lens dislocation into
the vitreous gel; long term miosis cheesewired the iris. (Figure
8) and lenticulodonesis caused corneal endothelial damage.
In parallel, Charles Kelman (1967)17
adapted ultrasonic dental deplaque instruments to phacoemulsify
the lens nucleus in the anterior chamber, allowing smaller
incision extracapsular surgery. Several years of development
were needed to bring phacoemulsification to its present day
popularity.
Meanwhile in the 1970s John Pearce developed a new reduced incision microsurgery,
with implantation of the IOL in the posterior chamber. Galand
in Liege, refined this to 'endocapsular' implantation, i.e.
into the natural place, the capsular bag (Figure
9). There was one disadvantage; capsular epithelial regeneration
could cloud the pupil later, but physics came to the rescue
with the development of the YAG laser capsulotomy (Fankhause
1983). At this time, surgical microscopes with foot pedal
controls gave better visibility during surgery. A scan Ultrasonography,
by measuring the axial length of the eye, increased the precision
of implant calculations.
The long history of surgical advance continues today with
Erbium YAG laser emulsifiers, even smaller incisions, (1mm
is possible) and foldable, injectable IOLs in new materials,
with ever more spectacular results. However, we have not yet
achieved Charles Kelman's aspiration17
for the millennium, i.e. "We must restore the patients vision
at 90 to that which they enjoyed at 19 - including accommodation".
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