Download Transpupillary Thermotherapy for classic subfoveal choroidal

Transpupillary Thermotherapy for classic subfoveal choroidal neovascularization : a
case report
AUTHORS
A O HASSAN FRCS, FRCOphth, FWACS
*O ODERINLO FRCS, DRCOphth
O OKONKWO FRCS DRCOphth
F OLUYADI FWACS FMCOphth
A O OGUNRO FWACS FMCOphth
S A OKE DO (WACS)
M ULAIKERE FWACS FMCOphth
INSTITUITION
EYE FOUNDATION HOSPITAL
27B Isaac John Street
Ikeja GRA
Lagos
* author for correspondence
Key words:
Transpupillary thermotherapy, Age Related Macular Degeneration, Subfoveal choroidal
neovascularisation, Fundus Flourescein Angiography.
SUMMARY
Aim: To report a case of a successful treatment of a classic subfoveal choroidal
neovascularisation with a Transpupillary Thermotherapy protocol.
Case report: a sixty seven year old pensioner who presented with six months history
of reduced vison in both eyes,he is a known glaucoma patient previously diagnosed
with primary open angle glaucoma. After anterior and posterior segment examination
with fundus flourescein angiography a diagnosis of a classic subfoveal choroidal
neovascularisation secondary to Age related macular degeneration OS with bilateral
cataracts and primary open angle glaucoma OU was made. Complete resolution of
the choroidal neovascular membrane was achieved with Transpupillary thermotherapy.
INTRODUCTION
Transpupillary thermotherapy (TTT) is a low irradiance large spot size prolonged
exposure (long pulse), infrared laser phtotocoagulation protocol 1.presently being
investigated for use in treatment of choroidal neovascular membranes
Its main advantages are that lasers in the infrared range are less absorbed by the
xanthophyll pigment and thus damage to the nerve fiber layer is minimized,
compared to the argon laser the infrared diode is also poorly absorbed by
haemoglobin allowing an improved ability to treat through preretina and subretina
hemorrhage 2. The relatively larger spot size also enables treatment of larger lesions
with a single burn.
TTT has only been recently put to use in our Hospital ,we present a case report of
one of the first patients diagnosed with a classic subfoveal choroidal
neovascularization that was treated with TTT.
CASE REPORT
Mr J A O a sixty seven year old pensioner presented to our hospital on the 9th of
December 2004 with complaints of reduced vision in both eyes over a period of 6
months, he is a known spectacle wearer and had earlier been diagnosed with
Chronic Primary Open Angle Glaucoma and is also a known hypertensive patient. He
had bilateral trabeculectomies in may 2002
Examination on the same day revealed visual acuities of OD hand movements only
and OS counting fingers only improving with a pinhole to 6/60. facial appearance
papillary light reactions and extraocular muscle movements were normal in both
eyes.
Both conjunctiva showed cystic filtering blebs with intraocular pressures of 12mmHg
OD and 16mmHg OS by applanation tonometry. gonioscopy revealed open angles of
Shaffer grade 3-4 in both eyes. There were definite posterior subcapsular cataracts
in both eyes but worse on the right.
Fundus examination revealed bilateral intermediate and large macular drusen, with
macular subretina hemorrhages OS .with cup to disc ratio of 0.8 in both eyes
An assessment of :1 bilateral age related macular degeneration, ? exudative OS
2 posterior subcapsular cataracts OU worse OD
3 bilateral primary open angle glaucoma
He had a fundus flourescein angiography in both eyes on 16th of December 2004
which revealed classic subfoveal choroidal neovascularization in the left eye (figure
1a and 1b)the right eye had no choroidal neovascular lesion.
Subsequently he had TTT laser treatment to his left eye on the same day the
angiography was done, parameters used were spot size 3.00mm power setting of 500
mW and duration of 60s . he also had a right extracapsular cataract surgery with a
posterior chamber implant on 25th of january 2005 .
His last clinic visit was on the 25th of may 2005 visual acuities in both eyes of
counting fingers OD and 6/60 OS a refraction revealed
OD -0.50DS/-4.00dcyl x 100 = 6/36
OS + 0.50DS/-1.50dcyl x 800 =6/36
add + 3.00DS = N36
Anterior segement findings were normal with the exception of R pseudophakia and
early posterior subcapsular cataracts. both discs were pale and cupped with CDR of
0.8 OU and normal intraocular pressures. He is presently taking G betoptic 0.5% 12
hourly OU and tabs antioxidants 1 bd. he feels much better and can even read
large prints, he is also able to make his way around better and really appreciates
his ocular care with us.
DISCUSSION
Subfoveal choroidal neovascularization still remains a management challenge to
ophthalmologist, medicare guidelines in the United States of America presently
favours phtotodynamic therapy for predominantly classic subfoveal neovascularization
3
, however in our environment this treatment modality is very expensive, each vial
of visudyne cost £850:00 which is approximately =N= 212,500:00 , this cost
excludes the amount needed for fundus flourescein angiography and the surgeons
fees, it should also be noted that repeated treatment sessions are needed and that
not all subfoveal neovascular lesions respond well to this treatment modality.
Hence the advent of multiple researches into the use of TTT in the management of
these lesions is of great interest. TTT has been evaluated for use in both occult and
classic choroidal neovascularization and encouraging results have been reported 4,5,6
In our hospital TTT is done with the IRIS Medical Oculight SLx infrared (810nm) solid
state laser with Tri-mode using a slit lamp delivery method and a Goldmanns 3
mirror lens,our prefared parameters of 60s duration ,3mm spot size and power
variation from 300mW to 700mW
is usually varied depending on the location of
the lesion and patients tolerability.
Mr J A O particularly responded well and figure 2 shows a complete resolution of
the subfoveal lesion at 2 months after treatment with his glaucoma control still
maintained.
We believe that with several ongoing clinical trials on the clinical uses of TTT for
choroidal neovascular membranes, the truth about its efficacy will be known , our
case report serves to add a positive word to the ongoing evaluation.
REFERENCES
1 Martin A Mainster, Elias Reichel
Transpupillary Thermotherapy for Age Related Macular Degeneration : Long pulse
photocoagulation, apoptosis and heat shock proteins.
Ophthalmic Surg. Lasers 2000 :31 : 359 -373
2 Allen B Thach, Jack O Sipperley, Pravin U Dugel, Scot R Sneed, Donald W Park,
Jennifer Cornelius
Large spot size Transpupillary Thermotherapy for the treatment of occult choroidal
neovascularization associated with Age Related Macular Degeneration.
Arch. Ophthalmology vol 121, June 2003 pages 817 – 820
3 Stephan Michels, Phillip J Rosenfeld
Clinical approach to Age Related Macular Degeneration
Review of Ophthalmology part 3 vol 3 October 2004 pages 3 – 7
4 Peep V Algvere, Carina Libert, Gunnar Lingard, Stefan Seregard
Transpupillary Thermotherapy for predominantly occult choroidal neovascularization in
Age Related Macular Degeneration with 12 months follow up
Acta Ophthalmologica Scandinavica
2003 : 81: 110 – 117
5 Allen B Thach, Jack O Sipperly, Pravin U Dugal, Scot R Sneed
Large Spot Size Transpupillary Thermotherapy for treatment of occult choroidal
neovascularization associated with Age Related Macular D egeneration
Arch Ophthalmol vol 121 June 2003 817 – 820
6 Singer M A , Willerson Jr D.
Transpupillary Thermotherapy in Treatment of occult and classic choroidal
neovascularization.
Presentation. The Vitreous Society 18th Annual Meeting, Cancun Mexico
January 7 – 11 , 2001.
Figure 1a
Figure 1 b
Figure 2