I nfectious

Complications

Infectious endophthalmitis

following scleral buckling

and vitrectomy

surgery

is a very uncommon

compli-

cation

and

almost

invariably.

in my experience,

the

result of intravitreal

injection

in the phakic

nonvitrec-

tomized

eye as a postoperative

maneuver. As a result.

great pains

should be

taken

to use

sterile

technique,

including

the administration

of pre- and postinjection

topical

antibiotics. when

administering

or

supple-

menting

gas intraoperatively

or postoperatively.

Treat-

ment

of

endophthalmitis

must be considered

an

extreme ophthalmic emergency

and must include

vit-

reous aspiration

for culture

and injection

of intravit-

real antibiotics.

with or without

vitrectomy.

Although

scleral implant

and explant

material

may

occasionally

become

infected (1--4%

of cases).

this

invariably

occurs

later

in the postoperative

period

(6

weeks

up

to

20

years). Rarely,

a scleral

abscess

may occur

in the

immediate postoperative

period.

heralded

by the development

of severe

ocular

pain, orbital

swelling

out of proportion to the surgical

procedure,

and

purulent

discharge.

Appropriate ther-

apy

fof

this disorder

includes

prompt diagnosis,

removal

of

the buckling

material,

intraoperative

orbital

and

scleral antibiotic

lavage,

and

high-dose

intravenous

antibiotic

therapy

after appropriate

cul-

ture and

sensitivity

studies

have been

performed.

Complications

and Postoperative

Management

125

nomenon rather

than a true complication.

Nonetheless,

it is a source

of

discomfort

to the patient

and

may

cause ptosis

and limitation

of extraocular

movement.

The incidence

and

severity

of the swelling

can

be

reduced by

choosing appropriately

sized

buckling

material, atraurnatic

surgical

technique.

and possible

use of solid rather than bulky

silicone sponge explant

material. Orbital swelling

is exacerbated

by

prone

positioning (required

for patients

with

intraocular

gas

bubbles). Icc

packs

can be

used

to treat

the swelling;

systemic steroids are

reserved

for severe cases.

When

lid swelling

is severe,

or accompanied

by

signs

of severe

orbital

inflammation

including

ten-

derness

and

redness,

the

possibility

of scleral

abscess

or a buckle

infection

should

be considered.

Muscle

Imbalance

Mild paresis

of the extraocular

muscles

is a common

phenomenon

during

the first

24-72 hours after scle-

ral buckling

surgery,

particularly

when

large

explarns

are

used,

or there has

been

extensive

dis-

section or

revision

of buckling

material.

TIle

use

of

long-acting

local

anesthetics

for retinal detachment

surgery may

also contribute

to this problem.

Motil-

ity almost

invariably

returns

to normal

within

2

weeks

after

surgery

and symptomatic

diplopia

can

be treated

in the

intervening

time by patching.

Up to

5% of patients

may

have some

degree

of permanent

muscle dysfunction.

usually correctable

with prisms.

The likelihood

of this

complication

is increased

by

the temporary

disinsertion

of muscles

during

scleral

buckling. a

technique

that

is rarely

indicated.

In

cases

of

prolonged

motil ity

imbalance, which

are

uncommon,

buckle

removal

or muscle

surgery

may

be required

with

or without

prism therapy.

126

MANUAL

OF RETINAL

SURGERY

may determine

the site of

infection

by palpating

the

globe through

the lids, and

identifying

the tender area.

Occasionally,

a fistulous

tract may

develop

in

the

absence of

frank clinical

infection,

although

it should

be assumed

for all practical

purposes

that the

devel-

opment of

a fistula

signifies

the

development

of

a

clinical buckle

infection. The

likelihood

of this com-

plication

is increased

by

poor

lid hygiene,

possibly

the use of sponge

rather

than

solid silicone

buckling

material. and

failure

to soak

the

buckling

material

intraoperatively

(prior to

insertion)

in

an~antibiotic

solution such

as fortified

ccfuzolin

or Neosporin.

Meticulous closure

of Tenon's

capsule

and

conjunc-

tiva and irrigation

of

the subconjunctival

space prior

to closure

with

a topical

antibiotic

may also reduce

the frequency

of this complication.

Once the patient

instances

in which

the buckle

has

been present

for

less than 6 weeks

and

the

severity

of

ocular

inflarn-

marion

is mild. serious

consideration

should be given

to conservative

therapy

with topical

and/or

oral

antibiotic coverage

as well

as meticulous

lid hygiene

to allow

Iormatiou

of a mature

choriorctinal

adhesion

thut will

muiutuin

retinal

reattachment

after

buckle

removal. In

the

majority

of cases,

removal

of the

buckling

material

is not accompanied

by retinal

rede-

tachrncnt after

this

time.

provided

that all the retinal

breaks

have

been sealed

by a thermal

modality

and

there

is not extensive

residual

vitreoretinal

traction.

I

favor supplemental

photocoJgulation

to areas of reti-

nal breaks

and/or

vitrcoretinul

traction

in

instances

where the buckle

must

be removed

approximately

1-2 weeks prior

to buckle

removal.

In

some

cases, erosion

of

the

conjunct!

va and

Tenon's capsule tissue

overlying

the buckle

may

occur without other

clinica!

signs

of infection

such

as mucopurulent

discharge

or conjunctival

injec-

·tion. In such

cases,

a

culture

should

be

taken to

ascertain

that

there

is no evidence

of a conjunctival

infection. In

some

instances,

the

situation

may

be

stabilized

by

placement

of a homologous

scleral

or

per icardial

patch

graft

over

the

exposed

buckle,

over which

conjunctiva

is then

reclosed

with an

absorbable

suture

after

the

edges

are trimmed.

It

can be categorically

stated

that

once

a fistulous

tract

or

area

of erosion

has

occurred,

reclosing

the eon-

junctiva

in that

area

without

placement

of additional

homologous

tissue either

in

the

form

of scleral

patch

graft

or

autologous

donor

conjunctiva

is

likely

to be

unsuccessful.

Most buckle

infections

are caused

by

staphylococcal

species

and

tend to

run an indolent

course.

Occasionally

gram-negative

infections

(including

Pseudomonas)

produce

a more

fulminant

picture and

may be associated

with

the

development

of scleral

ectasia and

frank

stuphy-

lorna beneath

the buckl ing material.

Great

care

should

be exercised

in

removing

buckles

in

such

areas because

of the risk

of accidental

perforation.

especially

in cases

of

gram-negative

infection.

It

is

also important

to remove

scleral

sutures

from all

quadrants

at the

time

of

buckle removal.

since

they

may contribute

to the

persistence of

infection.

Other Late Complications

A multitude

of

other

complications

may occur

that

are beyond

the

scope

of this chapter.

These

include

development

of proliferative

changes

of the

vitreous

as manifest

by

macular

pucker or

PVR.

ln

general.

the likelihood

of these complications

is increased

by

any of the other

inrraoperative

or early

postoperative

complications

including

scleral perforation.

subrcti-

na! hemorrhage,

choroidal

detachment.

and

fibrinoid

syndrome. The

reader

is advised to consult

the chap-

ter on vitrectorny

in

this and other

excellent books

on vitrectorny

methods

for the surgical

management

of these

proliferative

complications.

Fluid-Gas

Exchange

Fluid-gas

exchange

is an extremely

valuable tech-

nique that

is applicable to eyes

that have

previously

undergone

vitrectomy

with the

following

indications:

residual

or recurrent

subretinal

fluid accumulation;

persistent

intraocular

media

opacity;

evidence of

severe

intraocular inflammation

as manifest by a mas-

ocular compartment;

to facilitate

or prolong intraocu-

lar tamponade

in eyes

with appropriate

indications

(large retinal tears, proliferative

vitreoretinopathy,

and

occasionally

unresolved

vitreoretinal traction).

Fluid-

gas exchange

can be performed

at the bedside

or in a

minor surgical

suite

with either

topical

or retrobulbar

anesthesia,

although

the latter

is recommended

in

phakic and most pseudophakic

patients. Following

127

In aphakic

patients,

the

needle

is introduced

through

the

nasal or temporal

limbus

with the dorn-

inant

hand,

depending

on

which

eye is

being

exchanged,

and

brought

into

the

midpupillary

plane. A similar sequence

of

small withdrawals

and

injections

is completed

until

fluid equal

in volume

to the gas to be injected

has

been evacuated

from

the eye and

replaced

by

air

or

gas

(Figure

10-3).

Remaining

intraocular

fluid

can be

aspirated

from

the anterior

chamber

by gently

redirecting

the nee-

dle anteriorly

at

the

end

of

the procedure

(Figure

10-4). lOP

at

[he termination

of

the

exchange

should

be left

in

the

low-normal

range

in any

eye

in which

expansile

gas

is used.

The distinction

should

be

made between the

use

of expansile

gas

ill

general.

and

the

use

of

an

figure 10-\'

Injection

of air or gas

in phakic previously

vitrectornized

eye via

pars plana.

.

Figure

lO-~.

Later phase of Figure 10-3.

Note face-down

position

that

facilitates complete removal

of intraocular

fluid.

expansile concentration

of an expansile

gas. The

con-

centration

of 20% (SF6)

and

14% PFP are nonexpan-

site concentrations

of

expansile gases;

hence

no

severe increases

in

lOP

should

be anticipated

although

the

lOP

can

be

measured

in such

eyes

4--8

hours after exchange

to exclude

this potentially

cata-

strophic complication.

In some

cases, it

is advanta-

geous

to

use

an

expansile

concentration

of

an

expansile

gas

such

as 30-50% SF6,

or 20-25% PFP.

This

is particularly

true

in eyes

with a large

amount

of subretinal

fluid

or eyes

in

which

a total

fluid-gas

exchange

cannot

be performed.

In these instances,

it

is especially critical

that

the closing

intraocular

pres-

sure be left in the low-normal

to soft range;

lOP

mea-

surements

in the first

6-12 hours after

injection

can

avoid

major

problems.

Pressure

rises with

expansile

concentrations

of expansile

gas can be unpredictable

and severe,

hence

due

caution

must

be

exercised.

This complication

is particularly

troublesome

in eyes

in which

an encircling

scleral buckle

has been

applied

immediately

prior

to the fluid-gas

exchange,

in patients

who

received

nitrous

oxide

anesthesia

(without adequate

washout),

and in eyes

with preex-

isting rubeosis

or open

or closed

angle glaucoma.

In

such circumstances,

the

use

of an expansile

concen-

tration of

gas

is strongly

discouraged.

When

an

expansile

concentration

is used, I cur-

rently favor

the

use

of 30% SF6 or

20% PFP,

although

the

patient

must

be advised

that

a subse-

quent aspiration

of gas

may be required.

These

con-

centrations

can

help

to

provide tamponade

of

inferior

retinal

breaks

and

minimize

leakage

of

In patients

who

have

not undergone

vitrectomy,

intravitreal gas

may

be

used for recurrent

or

resid-

ual subretinal

fluid,

or

for extended

internal

tam-

ponade,

although

a

different

technique

must

be