Cornea is
a delicate and vital structure affording optical
properties as well as protection. It forms the
anterior 1/6th of the outer coat of the eye.
Anatomically Cornea is composed of five layers.
Inner most corneal Layer is the Endothelium.
It consists of a single layer of flattened cells,
which are hexagonal in shape. Their free surface
is bathed by the aqueous. This surface has microvilli
as the corneal epithelium. The endothelium is
purely an avascular stucture that is dependent
on the nutritional support provided by aqueous.
Embroyologically,
corneal epithelium and endothelium are the first
layers of cornea to appear in the developing
embryo. This happens at 12mm stage of embryo.
The endothelium is derived from neural crest
cells. Initially the corneal endothelium is
a bilayered structure but with further development
it evolves into a single layered hexagonal cells.
Endothelial cells also secrete their basement
membrane i.e. Descement's membrane. The endothelial
cells are connected to each other by hemidesmosomes
and they are also connected to their basement
membrane by desmosomes. These cell junctions
from an incomplete barrier to the influx of
fluid from the aqueous into the cornea.
Corneal
transparency is due to the regular arrangements
of the collagen fibrils in the corneal architecture.
Cornea stroma is in a state of relative dehydration
(deturgescence) that is necessary for its transparency.
Any influx of the fluid into the cornea will
result in loss of transparency of the cornea
and thus compromising its optical as well as
protective functions.
As
already mentioned that the endothelium is derived
from the neural crest cells, which means that
they don't have any regenerative capabilities.
So they baby is born with a fixed number of
endothelial cells that don't increase in number
during whole of his life. Rather there is a
decline with age as well as due to certain diseases
and insults to the endothelium. The lost endothelial
cell is replaced by the near by cells by enlarging
the size just to fill up the defect that has
been created by the lost endothelial cell.
The
age related endothelial cell loss makes the
picture more complex. At birth the endothelial
cell density is about 4000 cells/mm2. The cells
are lost from birth till adolescence quite rapidly
but there is a little loss from 20 years till
the fifth decade after which the cell density
declines rapidly till we have a number of about
2000 cells/mm2 in 8th and 9th decade. This is
still well above the number required for corneal
transparency, which is 400 to 700 cells/mm2.
In
addition to age related loss of endothelial
cells there are certain diseases that affect
the endothelial cell density and health. Diabetes
for instance will not cause much decrease in
the cell density but it will result in pleomorphism
and polymegathism thus compromising the function
of the endothelium. Damage to the endothelium
can also occur due to trauma most commonly operative
sometime mechanical, biochemical or thermal.
Surgical trauma to the endothelium has been
quite highlighted in this modern era of cataract
surgery. It is due to the fact that the cataract
surgery is the leading intraocular surgery being
performed now a days. Further the techniques
of cataract extraction are still in the process
of evolution.
To
start with it was intracapsular cataract extraction
(ICCE) that was most commonly performed. In
that era, it was the best available technique
of cataract surgery. This endothelial cell loss
was minimized by short duration of surgery with
no intraocular fluids used. Only causative factor
for endothelial cell loss was the mechanical
rubbing of cataract during expression and the
vitreous related keratopathy.
After
the ICCE era, Extracapsular cataract extraction
(ECCE) became popular. The irrigating fluids
that are used for ECCE result in changes in
endothelium. Further the residual lens matter
may incite inflammation that also adds up to
the endothelial cell loss. Mechanical trauma
is another contributory factor which is tried
to be prevented with the use of vicoelastics
but they can raise the intraocular pressure
that will again result in damage to the endothelial
cells.
Introduction
of phacoemulisification as a modern technique
of cataract surgery makes the picture quite
complex. In phacoemulsification there is mechanical
and biochemical insult ot the endothelium, which
is further, aggravated by the heat produced
during phacoemulsification. The vibrating ultrasonic
tip that produces lot of heat, which makes the
internal environment of eye unsuitable for the
endothelium. This heat is being counterbalanced
by continuous irrigation that makes the tip
cool but this irrigation flow also damages the
cornea. All
these factors under discussed contribute to
the ill health of the cornea. The straightforward
answer to prevent all these problems is to stop
doing surgery and no damage to cornea will ever
be reported but of course it is not possible.
So what is the answer?
Preoperative
evaluation and surgical plan is the top most
important thing to do first of all. Try to see
the endothelium and pick up an abnormality.
If in doubt, go for endothelial cell count.
Try to change your plan of surgery according
to the requirements of the situation. There
are viscoelastics that coat the endothelium
thus preventing any damaging effect of surgery
to the endothelium. Different viscoelastics
are being used and some are quite expensive.
In our experience the low cost viscoleastics
protect the endothelium quite efficiently. By
adapting the following steps:
· Stay 2.5 mm away from endothelium
· Try to maintain 30o angulation of the
phaco needle with entry site
· Controlled short bursts of Phaco energy
delivery over a period of time
· Appropriate use of solutions and viscoelastics
as the situation demands
The message is to take care of the corneal endothelium
and keep the utmost respect of this tissue because
once lost it will never be there for rest of
patient's life.
The
Risk of New Retinal Breaks Following Symptomatic
Posterior Vitreous Detachment
Nadeem Riaz
Department of Ophthalmology, Services Hospital,
Lahore
Abstracts
Purpose
of Study: The posterior vitreous detachment
(PVD) is sometimes associated with sight threatening
retinal tears or retinal detachment. The aim
of the study was to find the frequency of retinal
breaks developing within six weeks of an isolated
posterior vitreous detachment.
Materials and Methods: This study was carried
out between January 2000 and June 2001. Recruitment
of patients was from Eye Out-patients of the
Services Hospital, Lahore. Only those patients
were recruited who fulfilled the inclusion criteria.
All the patients were examined by the same consultant
and all of them were examined using slit lamp
bio- microscopy and indirect ophthalmoscopy
with scleral indentation. The patients with
vision threatening retinal breaks at presentation
were booked for treatment and the remainder
were reviewed six weeks later.
Results: A cohort of fifty four eyes (fifty
four patients) was selected for this study,
over a period of eighteen months. On presentation
to the clinic, four patients had round holes
anterior to the equator in the inferior retina,
one patient had a horse shoe tear near to the
equator and one patient had lattice degeneration
inferiorly with multiple tiny breaks. At the
second visit, one additional patient had two
round holes anterior to the equator but in this
patient the retina had been obscured by vitreous
haemorhage at the first visit. Another patient,
developed rhegmatogenous retinal detachment.
No patient in whom a full examination was possible
at the first visit developed further retinal
breaks.
Conclusion: A full examination of the peripheral
retina with three mirror contact lens and scleral
indentation at the time of presentation must
be done in all eyes with posterior vitreous
detachment and presence of vitreous haemorrhage
must arouse the suspicion of retinal breaks
until proven otherwise.
Introduction
Posterior
vitreous detachment (PVD) is a common, degenerative
condition in which the vitreous cortex separates
from the retina. Upto 20% posterior vitreous
detachments may be asymptomatic. In the rest
of the patients with acute posterior vitreous
detachment a variety of symptoms such as floaters,
flashing lights or a cobweb in the vision1 are
complained of. Upto 35% of symptomatic posterior
vitreous detachment are associated with retinal
breaks or detachments2-5. The presence of vitreous
haemorrhage increases the likelihood of an associated
retinal detachment1.
Patients presenting with symptoms of posterior
vitreous detachment are usually reviewed after
six to eight weeks but since the occurrence
of retinal breaks developing during that period
is not clear the aim of this prospective study
was to determine the frequency of this complication
in patients with acute symptomatic posterior
vitreous detachment during that period.
Material and Methods
The
patients fulfilling the inclusion criteria (Symptoms
of floaters, flashes, cobweb or a combination
of these; absence of history of ocular trauma
or surgery; absence of any previous ocular inflammation
and absence of glaucoma) were examined by the
same senior consultant (NR). Slit-lamp biomicroscopy
with a 78 Dioptre lens, Goldmann three-mirror
contact lens and indirect ophthalmoscopy using
a 20 Dioptre lens and scleral indentation were
used to examine the eyes to diagnose posterior
vitreous detachment. Those patients with retinal
breaks were immediately booked for treatment
and the remainder were seen after six week of
presentation.
A complete history of the presenting complaint
was taken including the duration and nature
of the symptoms as well as a family history
of retinal detachment and myopia. Patients'
refraction was recorded with Nikon speedy K
autorefractometer prior to dilatation of pupils
and the best corrected visual acuity was determined.
Intra ocular pressure (IOP) of both the eyes
were routinely measured using applanation tonometer.
The pupils were dilated with tropicamide 1%
and phenylephrine 10% drops. During slit-lamp
examination the vitreous was examined to look
for the presence of a Weiss ring or separation
of the posterior hyaloid face to diagnose posterior
vitreous detachment. The presence of pigment
particles in the vitreous was specially taken
notice of. The peripheral vitreous and retina
was examined by indirect ophthalmoscopy using
a 20 Dioptre lens and scleral indentation upto
the ora serrata. A Goldmann three mirror contact
lens examination was then undertaken. If no
sight threatening lesions were found the patient
was warned about the symptoms of retinal detachment
and was reviewed six weeks later to repeat the
whole examination again. At each visit patients
with symptomatic posterior vitreous detachment
and retinal breaks were immediately booked for
retinal laser photocoagulation. If no significant
pathology was found at the second examination
the patient were discharged.
Fifty
four eyes were seen with posterior vitreous
detachment. The mean age of patients was 39.6
years (22 years to 70 Years) (Fig.2), 35 of
the total patients were female (65%) (Fig.1).
Nineteen patients presented with floaters only
(35.2%), fourteen patients presented with flashes
only (25.9%), eighteen patients presented with
a combination of floaters and flashes (33.3%)
and three presented with the complaint of cobweb
effect (5.5%) (Table-1). At the first visit
retinal breaks were found in one patient who
presented with floaters only (5.2%), in another
patient who presented with flashes only (7.14%)
and three patients who had a combination of
symptoms (16.6%). None of the patients having
symptoms of cobweb effect developed retinal
breaks (Table-1). At the six weeks follow-up
visit one patient developed two round holes
anterior to the equator and this was the patient
in whom the view of retina had been obscured
by vitreous haemorrhage at the first visit.
Another patient was found to have rhegmatogenous
retinal detachment who was operated conventionally
with scleral buckling, cryopexy and drainage
of sub-retinal fluid with good results.
Table-1:
Percentage ratio of symptoms and
retinal breaks in patients of posterior
vitreous detachment
Symptoms
Retinal
Breaks
No.
%
No.
%
Floaters
19
35.2
1
5.2
Flashes
14
26.0
1
7.1
Floaters+Flashes
18
33.3
3
16.6
Cobweb
3
5.5
0
0
Total
54
100.00
5
9.25
Fig.1:
Gender percentage graph of patients with posterior
vitreous detachment
Four
patients (7.4%) were treated with laser photocoagulation
after the first visit. Three patients (5.5%) under
went prophylactic surgery (including the one with
perforated lattice degeneration). Twelve patients
did not keep follow up visit after six weeks.
Discussion
The
incidence of posterior vitreous detachment (PVD)
increases with age and with myopia5 and may
result following ocular trauma, surgery or Nd-YAG
laser capsulotomy. At points of vitreoretinal
adhesions the shear forces exerted at the retinal
surface by the eye movements may be sufficient
to create a retinal hole or break6. The likelihood
of retinal break depends on the patients' symptoms.
The prevalence of retinal holes in patients
with symptomatic posterior vitreous detachment
who notice only floaters is 4-5%1, which is
similar to asymptomatic retinal holes found
in clinical and post-mortem studies8-10. Flashing
lights either alone or with floaters are associated
with retinal breaks in 10-11% of patients and
71% may have a retinal break if vitreous haemorrhage
is found with symptomatic posterior vitreous
detachment1. The accurate diagnosis of posterior
vitreous detachment is often difficult to make
as a partial posterior vitreous detachment may
occur in the absence of a Weiss ring and the
posterior hyaloid face may still be attached
inferiorly in the presence of a Weiss ring11.
Ultra sound B-scan increases the accuracy of
diagnosis of posterior vitreous detachment,
but ultrasonography was not performed in this
study (except for the patient with vitreous
haemorrhage) since it is not a routine examination
for posterior vitreous detachment.
Fig.2:
Mean Age of patients presenting with posterior
vitreous detachment
The
findings of this study support the fact that
patients with a vitreous haemorrhage following
symptomatic posterior vitreous detachment should
be considered to have a retinal break until
proved otherwise. This study also confirms the
association between symptoms of flashing lights
and retinal breaks, the frequency of retinal
breaks is increased further if flashes occur
along with other symptoms.
Conclusion
By examining such eyes in detail at presentation
employing the methods mentioned, a significant
number of retinal breaks may be detected and
by timely intervention extensive surgical procedures
may be avoided.
References
1. Hikichi T, Trempe CL. Relationship
between floaters, flashes or both and complications
of posterior vitreous detachment. Am J Ophthalmol
1994;117:593-8. 2. Dayan MR, Jayamanne DGR,
Andrews RM, Griffiths PG. Flashes and floaters
as predictors of vitreoretinal pathology: is
follow-up necessary for posterior vitreous detachment?
Eye 1996;10: 456-8. 3. Diamond JP. When are simple
flashes and floats ocular emergencies? Eye 1992;
6:102-4. 4. Boldrey EE. Risk of retinal
tears in patients with vitreous floaters. Am
J Ophthalmol 1983; 96:783-7. 5. Jaffe NS. Complications
of acute posterior vitreous detachment. Arch
Ophthalmol 1968; 79: 568-71. 6. Okun E. Gross and microscopic
pathology in autopsy eyes. Am J Ophthalmol 1961;
51: 369-91. 7. Halpern JI. Routine screening
of the retinal periphery. Am J Ophthalmol 1966;
62: 99-102. 8. Byer NE. The natural history
of asymptomatic retinal breaks. Ophthalmology
1982; 89: 1033-9. 9. Davis MD. Natural history
of retinal breaks without detachment. Arch Ophthalmol
1974; 92:183-94. 10. Foos RY, Allen RA. Retinal
tears and lesser lesions of the peripheral retina
in autopsy eyes. Am J Ophthalmol 1967;64:643-55. 11. Kakehashi A, Inoda S, Shimizu
Y, Makino S, Shimizu H. Predictive value of
floaters in diagnosis of posterior vitreous
detachment. Am J Ophthalmol 1998; 125:13-5.
Authors:
Nadeem Riaz
Department of Ophthalmology
Services Hospital, Lahore.
Address for Correspondence
Nadeem Riaz
Department of Ophthalmology
Services Hospital, Lahore.
Comparison
of Irrigation and Aspiration (I/A) With Primary
Anterior Vitrectomy Vs YAG Laser Posterior Capsulotomy
Between
Eyes of Infants Having Bilateral Congenital
Cataract
Zia-ur-Rehman
Khan, Seema Qayyum
Department of Paediatric Ophthalmology The Children's
Hospital and
The Institute of Child Health, Lahore
Abstract
Purpose:
To compare the results and complications faced
with irrigation & Aspiration (I/A) with
primary anterior vitrectomy verses I/A with
early YAG laser capsulotomy between eyes of
infants having congenital bilateral cataract.
Patients and Methods: We launched a prospective
study from January 2001 in our Department in
which 40 patients (80 eyes) were included with
a minimum follow up period of 3-6 months. Patients
were aged between 7 days to 1 year but 95% were
less than 6 months old. One group of patients
had I / A only (group A) while the other group
had I/A with posterior capsulotomy and anterior
vitrectomy (group B).
Results: 33 patients (66 eyes)
under went I/A alone (group A1) on one side
and I/A with anterior vitrectomy (group B1)
on the other side. There were 3 patient who
had bilateral I/A only (Group A2) and four patients
had I/A with anterior vitrectomy bilaterally
(group B2). 21 (54%) eyes in (group A1) needed
YAG laser capsulotomy after four weeks to three
months post operatively. YAG laser was applied
under G/A. 18 Eyes (46%) in group A did not
need YAG laser application. 3 eyes in group
B needed YAG laser memberanectomy inspite of
having anterior vitrectomy. One eye in each
group had failed YAG laser capsulotomy and needed
surgical membranectomy. Similarly one eye in
each group needed repeat YAG laser. Two eyes
of one patient in group A1 developed thick layer
of elschnig's pearls needing repeat I/A followed
by YAG Laser application. In each group 2 patients
developed secondary glaucoma in one of their
eye. Table 1-3 are showing results in detail.
Conclusion: In our study simple
I/A with YAG laser posterior capsulotomy "If
needed" showed comparable results with
I/A and primary anterior vitrectomy in infants
having bilateral
Introduction
Congenital contract is a commonly faced problem
by almost every ophthalmologist. We have the
choice of removing infantile cataract with irrigation
and aspiration alone or I/A with primary anterior
vitrectomy. Primary implantation of intraocular
lens (IOL) in infants is still understudy. We
all understand the complications of primary
anterior vitrectomy which includes high cost,
technical skills, macular oedema, pupillary
distortion, vitreous wick syndrome, possibility
of retinal detachment and possible difficulty
of secondary implantation of I O L at a later
stage. Due to availability and relative ease
and safety of YAG laser application under general
anesthesia in our unit we decided to compare
these two procedures. At present we are comparing
anatomical results only and ignoring the functional
outcome. Which includes final visual acuity,
development or otherwise of squint and ease
of secondary IOL implantation. We know that
functional outcome is also affected by many
other factors such as proper correction of aphakia,
proper amblyopia therapy and regular follow-up.
Material and Methods
Total
of 40 patients were included from January to
September 2001 with a minimum follow up period
of three months and age between 7 days to one
year. Out of them 16 were females and 24 males.
Thirty-three patients (Group A1) had I/A in
one eye and I/A with anterior vitrectomy (Group
B1) in other eye. I/A was done after doing paracentesis
and anterior capsulotomy using capsulorrhexis
or tin can opener technique. Posterior capsule
was polished if needed. Other eye of each patient
had I/A as mentioned above and primary anterior
vitrectomy using ocuotome, (Group B1). Peripheral
iridectomy was performed in both procedures.
4 patients had bilateral I/A with anterior vitrectomy
(group B2) and 3 patients had bilateral I/A
only (group A2) due to some unrelated reasons.
Postoperative medications in both groups included
topical frequent steroid (Prednisone Acetate)
and an antibiotics (ofloxacin). Systemically
syrup Cephradine was given for one week. YAG
laser under general anaesthesia was performed
between 4 weeks to 3 months if clinically significant
thickening of posterior capsule developed. Patients
with other ocular or systemic diseases were
excluded from study.
Each procedure was done on one eye of 33 patients
as shown in Table-1. Three patients had bilateral
I/A and four patients had bilateral I/A with
anterior vitrectomy. So total of 39 eyes had
I/A alone (Group A) and 41 eyes had I/A with
anterior vitrectomy (Group B) as shown in Table-2.
It is obvious from Table-2. that 21 eyes (54%)
who had I/A alone (group A) needed YAG laser
capsulotomy and remaining 18 eyes (46%) did
not need YAG laser capsulotomy even after six
months of follow up. Inspite of having primary
anterior vitrectomy 3 eyes (7%) out of group
B did need YAG laser to clear the pupillary
membrane. Repeat YAG laser was required in one
eye out of each group. Failed YAG laser needing
surgical membractomy happened in one eye of
each group. One patient having bilateral I/A
(Group A2) developed thick Elschning's pearls
needing repeat I/A followed by YAG laser capsulotomy.
Two patients from each group developed pupillary
block secondary glaucoma and needed surgical
peripheral iridictomy but settled post operatively.
Table-1:
Number of patients according to
procedure done.
Procedure
Number
Percentage
I/A
alone (group A1) in one eye and
I/A with anterior vitrectomy (group
B1)
33
82.5
I/A
in both eyes group A2)
03
07.5
I/A
with ant: Vit in both eyes (group
B2)
04
10.0
Table-3:
Comparison of Outcome Between These
Two Procedures
Procedure
I/A(Group-A)
I/A
+ Ant.Vit (Group-B)
No.
of eyes done
39
41
Needed
YAG Laser
21
(54%)
3
(7.3%)
Repeat
YAG needed
1
1
Failed
YAG needing surgical membranectomy
1
1
Developed
elschning's pearls needing repeat
I/A followed by YAG laser
2
eyes
Nil
Developed
papillary block glaucoma needing
surgical PI
1
1
Satisfactory
outcome
39
eyes(100%)
40
eyes(100%)
In
summary all the patients of these two groups
achieved satisfactory clear pupillary area with
clear fundal view but some of the vitrectomy
group patients did develop pupillary distortion
due to vitreous presence in pupillary area.
Another interesting finding was that infants
of less than three months of age showed better
results from both these procedures as compared
to older patients. Younger infants had less
reaction, did not develop thick membrane and
their frequency of posterior capsular thickening
was also less.
We all understand that treatment of cataract
present at birth or developed within one year
of life is difficult problem faced by ophthalmologists.
Conventional I/A followed by posterior capsular
thickening use to require repeat surgeries in
the past. To solve this problem consensus developed
on doing primary posterior capsulotomy and anterior
vitrectomy but this procedure is fraught with
many complications which includes cost of ocuotome
and vitrectomy machine, loss of posterior capsular
barrier, risk of macular oedema, risk of retinal
detachment, pupillary distortion due to vitreous
incarceration, vitreous wick syndrome and possible
difficulty in putting secondary IOL. Keeping
in view the problems of primary, anterior vitrectomy
and availability of YAG laser application under
general anaesthesia, we have launched this study.
Uptill now we have done above 40 eyes having
each procedure and have not faced any significant
problem and achieved comparable results but
we will follow these patients further to compare
the functional outcome too, along with anatomical
consideration. We think that with YAG laser
we can also control the size of the opening
in posterior capsule leaving good shelf of posterior
capsule behind which will make implantation
of secondary IOL easier at a later stage.
Conclusion
Simple
I/A done as soon as possible after birth preferably
within 2-3 months of age and YAG laser capsulotomy
done later, "if needed" gives equally
good result as can be achieved with an invasive
procedure of primary anterior
vitrectomy.
Larger study with long-term follow up considering
functional outcome and ease of secondary implantation
is needed to confirm the finding of our study.
References
1.
Hing S, Speedwell L, Taylor D. Lens surgery
in infancy and childhood. Br J Ophthal 1990;
74: 73-7. 2. Keech RV, Tongue AC, Scott
WE. Complications after surgery for congenital
and infantile cataracts. Am J Ophthal 1989;
108: 136-41. 3. Taylor D. Choice of surgical
technique in management of congenital cataracts.
Trans Ophthalmol Soc UK 1981; 101: 114-7.
Authors:
Dr. Zia-ur-Rehman Khan
Assistant Professor
Department of Ophthalmology
The Children's Hospital &
The Institute of Child Health
Lahore.
Dr.
Seema Qayyum
Senior Registrar
Department of Ophthalmology
The Children's Hospital &
The Institute of Child Health
Lahore.
Address for Correspondence Dr. Zia-ur-Rehman Khan
Assistant Professor
Department of Ophthalmology
The Children's Hospital &
The Institute of Child Health
Lahore.
Treatment
of Age Related Macular Degeneration (AMD) -
A Trial
with Dietary Supplement of Vitamins and Minerals
Naeem
Ullah, Nadeem H. Butt, Mian M. Shafique, Huma
Kiani, Aamir Ahmad, Qandeel
Department of Ophthalmology Fatima Jinnah Medical
College/
Sir Ganga Ram Hospital, Lahore
Abstract
Purpose:
To find percentage of AMD and it's types among
the patients visiting Eye Department of Sir
Ganga Ram Hospital, Lahore and to asses the
efficacy and long term implications of dietary
supplement in terms of vision in AMD patients.
Method: This prospective study was
started in December 2000 and up till this date
157 patients have been treated with combination
of Vit-C 500 mg ,Vit-E 400 i.u., Beta Carotein
15mg, Zinc Oxide 80mg, and Cupric Oxide 2 mg.
It is an on going study which will last for
ten years to note long term effects and defects.
Both male and female patients between 41 and
89 years of age ,with either wet or dry form
of AMD were included. Out of 157 cases 114 had
Exudative (Wet) form of AMD-Group I . Forty
three cases had Non-exudative type of AMD- Group
II. FFA was done to evaluate and document the
type, nature and location of the disease. Dietary
supplement therapy was instituted and the patients
were followed every 4 weeks for six months.
Therapy was abandoned after 4 months and FFA
was repeated after 6 months. Later follow-up
of such qualified patients was done every 4
months.
Result: Improvement in the
disease and vision was better in Group-I. Ninety
Three percent (93%) patients either had visual
improvements by two lines with Snellen's Acuity
(27%) or vision did not deteriorate (66%). But
in Group_II , 83% showed deterioration of vision.
Only 2.4 % had visual improvement by one Snellen's
line, and rest 14.6% had stable vision.
Conclusion: The modalities
to treat AMD are Laser, Radiotherapy, PDT, Sub
macular Surgery, Translocation of Macula and
many more. Their success rate is variable. It
has been reported in literature that vision
may further deteriorate from complications,
which they may produce in some of the eyes.
The dietary supplement therapy is a safe and
useful method of treating AMD and visual results
are quite promising.
Introduction
Age Related Macular Degeneration (AMD) is a
serious blinding disease, which usually affects
the people after 40 years of age. In western
world it is one of the leading causes of blindness1.
In Pakistan no statistical data is available
up till now. We have started a study at Sir
Ganga Ram Hospital Lahore, to find out the percentage
of AMD and its types in our population. Simultaneously
a trial has also been started to treat AMD with
dietary supplements of Vitamins and Minerals.
The disease starts at molecular level. The enzymes
concerned with phagocytosis of debris of outer
segment of photorecepter cell, become deficient.
The debris is collected at subpigment epithelial
level in the form of drosen (Fig.1). The drosen
may also be formed by focal thickening of Bruch's
membrane. The nutrition of pigment epithelial
cell and photorecepter cell gets disturbed and
degeneration sets in. Sometime new vessels from
choriocapilaris penetrate through the retinal
pigment epithelail cells and spread between
this layer and photorecepter cells. These new
vessels may grow further to lie within the substance
of sensory retina (Choridal Neovascular Membrane-CNVM).
This form of AMD, the neovascular or exudative
(Fig.2) is commoner than dry type and if left
untreated provokes fibrosis and scarring of
macular area (Fig.3). Choridal Neovascular Membrane-CNVM
may be extrafoveal, Juxtafoveal or foveal. According
to its behaviour it may be called classic CNV
or occult CNV.
Only about 30 years ago AMD was thought to be
an incurable disease. With the advent of Argon
Laser, people used this modality to treat extrafoveal
AMD of neovascular type. The success rate, although
was variable, however it was a major breakthrough2.
Radiotherapy was used but the results were not
encouraging. Transpupillary thermotherapy was
also tried with poor results. Surgical removal
of Choroidal neovascular membrane from underneath
the macula has also been tried. In recent past
Photodynamic therapy (PDT) has also been included
in the list. Juxtascleral injection of Anecortave
acetate 15mg is also under trial these days
in USA. All the four mentioned methods do cause
some damage to the retina. Therefore research
on dietary supplement therapy was started; it
may come out to be helpful or else shall not
cause retinal damage.
Materials
and Methods
Study
on AMD was started in Department of Ophthalmology
FJMC and SGRH Lahore in December 2000. Patients
attending the eye out patient department were
screened for AMD. It is an ongoing study that
will continue till 2010. It has two aspects.
One is to find out the percentage of AMD and
its types and the other is to assess to the
efficacy of dietary supplements for treatment
of AMD in this part of the world.
The patients who visited eye department had
fundus examination and the patients with AMD
were registered. They had a detailed evaluation
of the visual function, associated ocular or
systemic diseases; and had to undergo Amsler
grid examination and Fundus Fluorescein Angiography
(FFA) to be aware of the base line parameters.
Total number of AMD patients was 157 in two
years time. Group 1 was exudative variety and
had 114 patients, while Group 2, dry type had
43 patients. Dietary supplements with Vitamins
and Minerals were instituted to all AMD patients.
The recommended dose for the treatment of AMD3
is as follows:
Vitamin C 500mg
Vitamin E 400 I.U.
b-Carotein 15 mg
Zinc Oxide 80 mg
Cupric Oxide 2mg
Only prescribing Tablet Oculovit Extra fulfills
the requirement of the recommend daily dose
twice a day. This supplement was advised for
a period of four months to all types of AMD
dry or exudative, CNV occult or classic (Fig
4), and to all AMD locations (Fig.5). The same
preparation is being used in USA for treating
this disease3. The patients were examined every
six weeks for measurement of visual acuity,
Amsler's Test and Fundus Examination. FFA was
repeated after six months.
Results
The
percentage of types of AMD in Dietary Supplement
Study- Sir Ganga Ram Hospital Chapter (DSS-
SGRH Ch.) has been depicted in Fig 4. Percentage
of blindness in DSS- SGRH Ch. has been given
and compared with the figures of American Academy
of Ophthalmology in Fig.6.
