6 MANUAL OF RETINAL SURGERY

detachment prior

to funduscopic

examination. An

afferent pupillary defect

is usually

present

in

the

affected

eye. Applanation

tonometry

may

be used

to record

the intraocular

pressure.

In most cases the

intraocular

pressure

is lower

as a result

of the reti-

nal detachment,

but

the

presence

of hypotony

should raise

the possibility

of

accompanying

choroidal

detachment.

In patients

with

a history

of

glaucoma, the

usc of cycloplegic

agents

for preop-

erative

pupillary

dilation

may

cause

a

rise

in

intraocular pressure.

The lids and conjunctiva

should

be examined

for

blepharitis

or

conjunctivitis

prior to

pupillary

dila-

tion. Phenylephrine

hydrochloride

may constrict

conjuncti

val

blood

vessels

and

mask

an ocular

infection. The

presence

of severe

blepharitis

or con-

junctivitis

should

lead

to a delay

in surgery

until

the

condition has

been treated.

Limitations

in ocular

motility

or

strabismus

should

be measured

and

noted.

If the patient

has

had previous

retinal surgery

and

abnormalities

in

ocular

motility

are

noted,

the

patient should

be

informed

of

the increased

possibility

of

diplopia

after the

retina is reattached.

On slit-Iump

examination.

ahnormalities

in

corneal

clarity

or size

should

he

noted. The depth

of the anterior

chamber

should

be

checked.

In

patients

with

a narrow

peripheral

angle. gonioscopy

is indicated

to avoid

angle closure

by pupillary

dila-

tion. Such eyes may require

laser

iridectomy prior

to pupillary

dilation

and

retinal

detachment

surgery.

Any patients

with

a history

of

glaucoma

or pupil-

lary rubeosis

should also undergo

gonioscopy.

In patients

with Marfan's

syndrome

or a history

of

ocular trauma. lens

subluxation

or phacodonesis

may

also be present. If an intraocular

lens implant has been

inserted, the

type of implant

and integrity

of the

pos-

terior capsule

following extracapsular

cataract

extrac-

tion should

be noted.

In aphakic

patients, vitreous

fibrils may be displaced

anteriorly

through the

pupil

by ;1 bullous

retinal detachment.

Vitreous

strands

to

tbe cataract

wound

should

be

studied. The hyaloid

face may

be in contact

with

the corneal

endothelium,

resulting

in localized

corneal

edema.

In

phakic

patients

with

symptoms

of posterior

vitreous

separation,

it

is

helpful

to examine

the

.anterior vitreous with

the slit

lamp.

The

presence

of

pigment (frequently present

only

after

vertical

and

horizontal eye

movements)

almost

invariably

indi-

cates

the

presence

of

a retinal

tear.

After the slit-lamp

examination

is

completed,

maximum

pupillary

dilation

should be obtained

prior

to funduscopic

cxamination.

Cyclopentolatc

hydrochloride I % and

phenylephrine

hydrochloride

2.5%

(or 10% in refractory

cases)

can

be used in

combination

at 20--30 minute

intervals

until

maxi-

mum dilation

occurs.

In patients

with

iris-fixated

intraocular

lenses, dilation

should

be

done

more

cautiously

to

prevent

dislocation

of

the

implant.

The funduscopic

exurninat

ion

consists

of three

parts:

(1) indirect

ophthalmoscopy

with

scleral

depression. (2)

noncontact biomicroscopy

of

vitreo-

retinal

relationships

using

an

aspheric

lens,

and (3)

contact

lens examination

of

the

retina

and anterior

chamber angle.

The

following

instruments

should

be available:

•

Indirect

ophthalmoscope

with

small

pupil

anachment

•

Scleral depressor

•

Fundus drawing paper

•

Colored

pencils

An indirect

ophthalmoscope

should

be chosen

that is lightweight

and fits

comfortably.

since

the

examination

in some

difficult cases may

take up to

60 minutes.

A small

pupil

attachment

is helpful

for

poorly dilated

eyes

or in pseudophakic

eyes

with

peripheral lens

remnants.

The room

is darkened

and

indirect

ophthalmoscopy

is started when

the exam-

iner

is dark

adapted.

The

patient

is placed supine

on

an examining

chair

or table. The chin

is extended

forward slightly. The

examiner

stands at the

head of

the patient

and

the

fundus

drawing

paper

is

kept

next to the

head

of

the

patient

on

the

side

of

the

examiner's

writing

hand

or on the patient's

chest.

The

120 'dock

meridian

of the drawing

is directed

toward

the

patient's

feet and the examiner

is posi-

tioned opposite

to

the

meridian

of interest

and

sketches

exactly

what is observed.

By

placing

the

drawing

upside-down.

one

obviates

the need

to

transpose

the inverted image

of the

indirect

oph-

thalmoscope.

The

beginning examiner

should learn

to hold the

lens with

the nondorninunt

hand so that

the writing

hand

can

be: used

for drawing

or scleral

depression.

The conventional

color scheme

used

for

fundus drawing is:

Light

blue: retinal detachment

Dark

blue: retinal veins, margins

of

retinal

breaks

Light

red: attuched

retina

Dark

red:

retinal

arteries,

preretinal

or

intraretinal

hemorrhages

Yellow: inrrare

rinal

or

subretinal

e xudute s.

subretinal bands

Brown:

choroidal

detachment.

nevi.

or

melanomas

At the beginning

of the

ex arnination.

the inten-

sity of the

indirect ophthalmoscope

is reduced

ro

allow

the patient to

adjust

to the brightness

or' the

light. Initially.

a broad

survey

of the funduscopic

findings is

obtained without

sc lcrul depression.

When

the

patient

is more

comfortable

with

the

examining

light. the illuminarion

can

be

increased.

The meridians

delimiting

the

edges

of

the retinal

detachment

are

first

nored

and

the

extent of

detachment

is

sketched

onto

the fundus

drawing.

The

fundus

drawing

paper

(Figure

2-1)

contains

three concentric

circles. The

inner

circle

represents

the equator

of the fundus,

the

middle circle

repre-

sents

the ora

serrata.

and

the

outer

band

the

pars

plana.

Retinal

breaks

vixible without

scleral

depression

are localized

and drawn.

Following

the retinal

blood

vessels

out

to the periphery

allows

system-

atic

examination

of

the

entire

fundus.

Scleral

depression

is

required

for

examination

of

the

peripheral

retina. The patient

is more comfortable

when

scleral

depression

is started

temporally.

The

temporal periphery

is more

easily visualized

and, as

the

eye softens

from scleral

depression.

the nasal

fundus can

be more easily

examined. Optimal visu-

alization

of

the

peripheral

fundus

is usually

obtained when

the examiner

stands directly

oppo-

site to the

meridian

of interest.

In patients

with

small pupils or peripheral

lens opacities,

visualiza-

tion

of retinal

breaks

may

also

be improved

by turn-

ing the patient's

head

toward

the

examiner

and

ask-

ing the patient

to

look toward

that

meridian.

Specific

features

of

the

reti nul

detachment

should be

noted

on the

fundus

drawing:

I. The

rc lur ioush

ips

of

rctinal

blood

vessels

and

vortex

veins

to the

location

of

breaks should

be

drawn

to provide

landmarks

for intraoperative

localization.

These

may

be

helpful

during

surgery

if visualization

decreases

due

to corneal

edema

or vitreous

hemorrhage.

Avulsed or bridg-

ing blood

vessels

over

retinal

tears

should

also

be noted.

2. The height

or elevation

of the

retinal detachment

should

be studied

to determine

whether drainage

of subretinal

fluid

is required.

More

bullous

arcus are preferable

for possible

drainage

sites.

3. Areas

of chorcoretinal

pigmentation

and

demar-

cation

lines

should

be indicated.

Demarcation

lines may help

to

localize

the region

of

the reti-

nal breaks.

4. Areas

of

per iphc rul

lattice

degeneration

and

areas

suspicious

for

retinal

breaks

should

be

noted.

Some Dr' these

areas

will require

exami-

nation

under higher magniticatinll

using

the con-

tact lens.

S. When

multiple

breaks

arc

present. their

antero-

posterior locution

should

be

accurately

depicted.

As a general

rule.

vortex

veins delineated

the

equator and

can be

helpful

in

the precise

deter-

mination of

anteroposterior

location. This

infor-

mation

will be used

to plan

the

size

and

extent

of scleral

buckling.

6. Lines

of circumferential

traction

in the

anterior

retina

and star or fixed tolds

should

be indicated.

By observing

the

mobility

of the retina

as

the

patient

moves

the

eye, the

severity

of

traction

can be evaluated.

Poor mobility

indicates

that

the retina

is

stiffened

by epirctinal

membranes

and may require

vitrcctorny.

The

posterior

pole

is usually

reserved

for

the

final part

of the examination

with indirect

ophthal-

moscopy.

A 14-diopter

condensing

lens

provides

higher

magnification

for small

breaks.

Macular

holes. cysts, or

macular

pucker

may

be

present.

Posterior

breaks may

also be

present

ncar

the edge

of a staphyloma

or coloboma

or

adjacent

to

larger

retinal blood vessels.

When

the examination

is completed

in

the

supine

position.

the

patient

is

examined

in

the