Original Article
Pediatric Aphakic Glaucoma
Zia
Muhammad, John
Grigg, Ikramullah, Ihsan Ali
Pak J Ophthalmol 2019, Vol. 35, No. 3
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See end of article for authors affiliations …..……………………….. Correspondence to: Zia Muhammad Prof & Head
Department of Ophthalmology, Bacha Khan Medical College, Mardan, Pakistan. Email: eyesurgzia@gmail.com |
Purpose: To find the frequency and
pathogenesis of post-operative aphakic glaucoma in children operated for
congenital cataract at Mardan Medical Complex, Mardan, Pakistan. Study Design: Retrospective Cohort study. Place and Duration of Study: Mardan
Medical Complex, Mardan between January 2001 and December 2014. Material and Methods: All
cases were operated for
congenital cataracts between the ages of 2 months to 30 months were included
in the study. Babies having congenital cataracts with increased intraocular
pressure (IOP), those showing signs of congenital glaucoma and those having
congenital cataracts with specific syndromes were not included in the study. Results: We reviewed the records of 110
patients who had bilateral lens aspiration for congenital cataracts. We found
7 patients (12 eyes) who developed increased intra-ocular pressure (IOP)
after bilateral lens matter aspiration for congenital cataracts. Four
patients (three males one female), developed early onset pupil block
glaucoma, (2 bilateral and 2 unilateral) while in 3 female patients the onset
of glaucoma was delayed for several months to years and was of the open angle
type in both the eyes. Poor compliance with follow up, poor pupillary
dilatation, prolonged surgical time, severe inflammation and residual lens
matter are some of the risk factors for early onset pupillary block aphakic
glaucoma in pediatric age group. Conclusions: Pediatric aphakic glaucoma is
a significant complication of congenital cataract surgery which requires
continuous followup of the patients. Key Words: Pediatric aphakic glaucoma,
Congenital cataract, Aphakic open angle glaucoma, Pupil block, Primary
posterior capsulotomy, |
Aphakic Glaucoma is one of the most
serious, sight threatening and well recognized complications following
uncomplicated pediatric cataract surgery1,2. The incidence has been reported in the literature to be between 15% and 45%3,4. The incidence of aphakic glaucoma seems to increase when these
patients are followed up for longer periods. 2,4 In patients who
were watched for more than 5 years, the incidence of glaucoma in aphakic
patients has reached to levels as high as 41%4.
Pupillary block glaucoma is becoming less common because of the
technical innovations and improvements in ophthalmic equipments, cutting
instruments and procedures. However, aphakic glaucoma still is a challenge and
a sight threatening complication of pediatric cataract surgery2,4,5.
Some of these children may develop aphakic glaucoma with open angles. The exact
pathogenesis of this form of open angle glaucoma in these patients is unknown5.
The diagnosis of aphakic glaucoma in children with open
angles is quite a challenging task and at times difficult to detect. Poor post-operative follow-up and absence of typical
symptoms increases the risk of delayed diagnosis. Also patients need to be
examined under general anesthesia to reach the diagnosis. Aphakic children require regular
monitoring for IOP
and optic disc changes.
Aphakic Glaucoma occurring after removal of congenital cataract is an
established complication. Mills et al2 have observed a bimodal
presentation of aphakic glaucoma in children. It may be in the form of
pupillary block glaucoma due sticking of the pupillary margin to the anterior
vitreous face; or due to angle closure from peripheral anterior synechiae2,3.
Or it may be an open angle type glaucoma of late onset.
Surgery
before 9 months of age and micro-cornea are two
important risk factors for development of glaucoma following pediatric cataract
surgery. It has been recognized that visual outcome is
excellent if surgery is performed in neonates during the first few weeks of
life6,7. But early surgery
between 1–2 weeks of age also make the babies vulnerable to develop aphakic
glaucoma8. Johnson et al9,
have not observed any relationship between age at cataract surgery (prior to 12
weeks of age) and development of glaucoma. Others10 have reported a
greater risk of glaucoma during the initial nine months of age.
`We undertook this study to find out the frequency
of aphakic glaucoma in the patients operated for congenital cataracts at our
Institution. This will help us identify the causes of pediatric aphakic
glaucoma. Also we may be able to modify our techniques to avoid this vision
threatening complication.
MATERIAL AND METHODS
We analyzed the documents of all pediatric patients who were
operated for congenital cataracts between the ages of two months to 30 months
from January 2001 to December 2014. Babies having congenital cataracts
with increased intraocular
pressure (IOP), those showing signs of congenital glaucoma and those having
congenital cataracts with specific syndromes were not included in the study.
Patients were labeled as
having aphakic glaucoma if repeated intraocular pressure (IOP) measurements were
greater than 25 mm Hg after follow up of these patients. Schiotz and Perkins
applanation tonometers were used to determine IOP.
In all our patients, we performed
closed chamber anterior capsulotomy followed by lens matter aspiration through
a limbal incision. No posterior capsulotomy and no vitrectomy was performed.
All patients were left aphakic, and none of the patients received intraocular
lens (IOL) implant. One hundred and ten lens aspirations were performed by the
same surgeon (ZM). Both eyes were operated in the same sitting taking strict
aseptic precautions. After completion of the surgical procedure, all patients
received sub-conjunctival injections of Gentamycin and Dexamethasone. Topical
medications (hourly dexamethasone (Maxidex, Alcon) and 4 hourly Tropicamide 1%
(Mydriacyl 1%, Alcon) eye drops were started 2 hours after the operation. From
the next day 2 hourly dexamethasone and 4 hourly Tropicamide 1% were continued
over a 6 week period. Moxifloxicin eye ointment at night was used for couple of
weeks. We re-examined the patients on the 3rd day post-operative day
to assess the wound, pupil, performed retinoscopy and advised glasses.
RESULTS
We reviewed the records
of 110 patients who had bilateral lens aspiration for congenital cataracts. We
found 7 patients (12 eyes) developed increased intra-ocular pressure (IOP)
after bilateral lens matter aspiration for congenital cataracts. Four patients
(three males one female), developed early onset pupil block glaucoma, (2
bilateral and 2 unilateral) while in 3 female patients the onset of glaucoma
was delayed for several months to years and was of the open angle type in both
the eyes. Descriptive analysis of the study is given in tables 1-5.
Table 1: Demography.
Total No. of Patients: 110
No. of Male Patients: 69
(62.73%)
No. of Female patients: 41
(37.27 %)
Table 2: Age & Sex Distribution.
|
Males |
Females |
Total |
|
|
2 – 6 Months |
30 |
16 |
46 (41.81%) |
|
7 – 12 Months |
21 |
15 |
36 (32.72 %) |
|
13 – 30 Months |
18 |
10 |
28 (25.45 %) |
Table 3: No. of Patients who developed Aphakic Glaucoma 07 (6.36%).
|
Age |
Males |
Females |
Total |
|
1 – 6 Months |
02 |
01 |
03 |
|
7 – 12 Months |
01 |
02 |
03 |
|
13 – 30 Months |
Nil |
01 |
01 |
Table 4: Type of Glaucomas.
|
Age |
Pupil Block glau. |
Open Angle Glau. |
Total |
|
2 – 6 Months |
03 |
|
M 02/F 01 |
|
7 – 12 Months |
01 |
01 |
M 0/F02 |
|
13-30 Months |
|
02 |
M 0/F 02 |
Table 5: Details of Patients Who
Developed Aphakic Glaucoma.
|
No. |
Name /Age/Sex |
LMA Date |
A G Dx. On |
Surgery |
Type of AG |
Gap |
|
1. |
Patient A 4 months/M |
March 2012 |
May 2012 |
10/5/2012 |
Right eye Pupil
block |
67
days |
|
2. |
Patient B 5 months/M |
May 2014 |
June 2014 |
10/6/2014 |
Left eye Pupil block |
19
days |
|
3. |
Patient C 5 months/F |
March 2008 |
April 2008 |
22/4/2008 |
Bilateral Pupil block |
28
days |
|
4. |
Patient D 8 months/M |
February 2013 |
March 2013 |
12/3/2013 |
Bilateral Pupil
block |
33
days |
|
5. |
Patient E 12 months/F |
February 2004 |
May 2004 |
6/5/2004 |
Bilateral OA
glaucoma |
78
days |
|
6. |
Patient G 18 months/F |
August 20013 |
February 2014 |
25/2/2014 |
Bilateral OA
glaucoma |
6
months |
|
7. |
Patient H 30 months/F |
June 2005 |
June 2011 |
16/6/2011 |
Bilateral OA
glaucoma |
6
years |
DISCUSSION
Congenital cataracts may be classified as congenital
idiopathic cataracts, congenital cataracts associated with other ocular or systemic
anomalies (aniridea, congenital rubella syndrome etc) and Developmental
cataracts10.
The angle findings are normal in congenital idiopathic
cataracts and signs of glaucoma and increased IOP are usually not present.11
Glaucoma in these children results from the surgical removal of cataracts with
or without IOL implantation.
The diagnostic criteria as defined by
the Glaucoma Research Network consist of two or more of the following: IOP more
than 21 mm Hg, progressive increase in the cup to disc (C/D) ratio, asymmetrical
cupping of the discs, corneal Haab’s striae, enlarged corneal diameter (> 11
mm in the newborn, > than 12 mm in children below one year and > than 13
mm at any age and progressive myopia/myopic shift. Glaucoma may be suspected
when there is increase in the size of the globe with raised IOP without other
features mentioned above.
We reviewed all infants 3 weeks post surgery and
enquired from the mother about the progress and development of any new symptoms.
The common symptoms in suspected cases were photophobia and irritability of the
infants. Infants with these symptoms were called for examination under general
anesthesia for IOP measurement, assessment of anterior chamber angle and depth,
horizontal corneal diameters, refraction and fundus examination. Aphakic glaucoma was suspected when the baby was having repeated
intraocular pressures (IOPs) greater than 25 mm Hg, progressive increase in the
C/D ratio and increase in the horizontal corneal diameter after congenital
cataract surgery. Schiotz or Perkins applanation tonometry was used to
determine intra-ocular pressures. Patients with these findings were
started with medical treatment or glaucoma surgery if the pressure was not
controlled with topical medications. Glaucomatous eyes with pupil block and
shallow anterior chambers were treated with removal of the inflammatory
pupillary membrane if present, breaking the posterior synechie, peripheral
iridectomy and anterior vitrectomy and re-formation of the anterior chamber. In
glaucomatous eyes with open angles, trabeculecomy was performed if there was
poor response to topical anti-glaucoma medications.
Surgery for congenital pediatric cataract increases the risk for
developing aphakic glaucoma. Pre-operative
angle findings do not suggest a role in pathogenesis of this form of glaucoma12.
The precise cause for the open angle glaucoma following pediatric
cataract surgery is not known but may be triggered by trabecular meshwork
dysfunction from surgically induced inflammation, corticosteroids `induced
increased IOP, damage to the developing angle structures by the residual lens
fibers or vitreous interfering with the aqueous drainage or angle
maldevelopment13.
Two risk factors most commonly associated with glaucoma after
pediatric cataract surgery include age at the time of surgery and micro-cornea.
There is a higher risk in infants operated during the first year of life. A
number of studies14,15 report an increased risk of glaucoma at
different ages in the first 12 months of life. Some observers16 have
reported that cataract surgery in the first 9 months of age carries a higher
risk of aphakic glaucoma.
In this series, we operated on 110 infants (220
eyes) having bilateral congenital cataracts with ages ranging from 2 months to
30 months. Both eyes were operated in the same sitting. Based on eye count, 12 eyes (5.45%) of our
patients developed aphakic glaucoma. Based on the patients count 7 of our patients
(6.36%) developed aphakic glaucoma. Postoperative glaucoma following pediatric cataract surgery has
been reported to vary between 6% and 26% of eyes (15% to 45% of patients) among
children operated before, as well as after one year of age17,18.
Rabiah19
has reported an incidence of 37% if the cataract was removed during the first 9
months of age. The risk dropped to 14% when surgery was delayed to between 9
months and 2 years of age. The risk of developing glaucoma further drops to
only 9% if surgery is performed between 2 and 3 years of age. After bilateral
lensectomy within the first month of life, Vishwanath et al8 found an incidence of 50% in at least one eye
which decreased to 14.9% if surgery was delayed beyond one year. The incidence
of glaucoma in our patients is relatively lower compared to the above studies.
We need
to counsel the parents, and relatives about the importance of regular
examination and follow-up. It will be worthwhile to involve both parents during
the course of the treatment of their child, from identification to surgery and
follow-ups. The pediatric unit should have trained staff with child-friendly
attitude for greater acceptance of the available pediatric ophthalmology
services.
Aphakic glaucoma itself poses a significant
diagnostic challenge, as classical manifestations are not always present and
children are uncooperative for proper examination. It can be extremely
challenging to measure the IOP with the child awake and sedation is usually
required. In our series we did not see any
patient before 2 months of age because of late presentation.
Fortyseven infants (42.72%) were operated between
2 months and 6 months of age. Sixty three patients (57.26%) were operated between 7 months and
30 months. We did not perform posterior capsulotomy and anterior vitrectomy in
any of our patients. This could be the reason for the lower incidence of
glaucoma in our patients.
Michaelides and co workers17 have reported a marked
increase in risk of aphakic glaucoma after bilateral lensectomies at an early
age. They have also observed that respecting the posterior capsule may be associated
with a lower rate of aphakic glaucoma.
The pattern of aphakic glaucoma in our series was bimodal as
reported by Mills et al2.
In our series 4, (3.63%) of our patients
developed early-onset glaucoma. Two patients developed bilateral whereas two patients
developed unilateral pupil block/angle closure glaucoma. The time interval
between cataract extraction and development of pupillary block was from 19 days
to 67 days’ post operative. In our study, pupil block with secondary angle
closure caused the early-onset post-operative aphakic glaucoma. This was due to
severe inflammation leading to synechia formation, absence of peripheral
iridectomy, and poor pupillary dilatation causing pupil block and raised IOP.
Early-onset glaucoma typically occurs during the first few weeks
after surgery and has an abrupt onset. Mills and
co-workers2 have reported the occurrence of pupillary block glaucoma
within the first few months after lensectomy while the open-angle glaucoma type
has a delayed onset (average 7.4 years).
Chen et al 16
however, have not witnessed the bimodal pattern in their patients
operated for congenital cataracts. They found the filtration angles open in 94%
of their patients. In our series, eyes developing glaucoma in the first few
weeks after surgery had closed angles.
The open-angle glaucoma occurring in both eyes in three of our
patients was delayed for a period from 3 months to 6 years. Patients with delayed
onset glaucoma (6 eyes) in our series were without any symptoms and were
diagnosed on routine examination.
In a study conducted by Simon et al
4 open angle glaucoma occurred 5.5 years after surgery in children. In
other studies1, the onset of glaucoma was delayed up to 12.2 years
following cataract surgery in the pediatric age group. In our follow up of 3 years to 14 years, we
found a delay of 3 months to 6 years before the patients developed open angle
glaucoma. The incidence of open angle glaucoma increases with longer post
operative follow up of these patients. Children operated for congenital
cataracts have a perpetual risk of developing open angle glaucoma throughout
their lives18,19,20.
Whether an intact posterior capsule and putting
an intraocular lens (IOL) has a protective role for development of aphakic
glaucoma is not clear. Although primary posterior capsulectomy and anterior
vitrectomy may aid in early visual recovery, and may help reduce the risk pupil
block but it also increases the chances of open-angle glaucoma down the line. Michel Michaelides et al17 found the development of aphakic glaucoma in 100% of
their patients who had posterior capsulotomy during lensectomy for pediatric
cataracts.
Rabiah21
also has reported an increased risk of aphakic glaucoma after primary posterior
capsulotomy/anterior vitrectomy. Papadopoulos et al22 noted a
reduced incidence of aphakic glaucoma when the posterior capsulotomy was not
performed at the time of primary lens aspiration in children. In a series of
377 eyes who had lensectomy with posterior chamber IOLs, Asrani et al1
found only one patient developing glaucoma. The follow up however, was only 3.9
years.
The limitation of our study was that it was performed at a
single center. Further studies are needed with more patients to determine more
generalizable results. The challenges we are facing include; lack of awareness
about pediatric cataracts, delay in presentation for surgery, poor access to
quality surgical care, and poor follow-ups. In addition, lack of financial
resources, inadequate health facilities, and an insufficient number of
pediatric ophthalmologists are other major obstacles.
CONCLUSION
Pediatric aphakic glaucoma may be angle-closure type secondary to
pupillary block2 which occurs within the first few weeks after
surgery. Etiology of this type of glaucoma include surgery at an early age, severe
inflammatory reaction, poor pupil dilatation, not performing an iridectomy and
shallow anterior chamber due to poor wound suturing.
Post operative open angle glaucoma
is unpredictable and can occur months and even years after surgery.1 This
form of glaucoma is probably not directly related to the procedure itself and often
difficult to manage.
REFERENCES
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Asrani SG, Wilensky JT. Glaucoma after congenital cataract surgery. Ophthalmology, 1995; 102:
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Author’s Affiliation
Zia Muhammad
MBBS, MCPS, FCPS, FICS,
Fellowship in Pediatric Ophthalmology, University of Sydney, Australia.
Prof & Head
Department of Ophthalmology,
Bacha Khan Medical
College,
Mardan, Pakistan.
John Grigg
MBBS (QLD) MD (SYD)
FRANZCO FRACS
Professor and Head,
Discipline of Ophthalmology, Save Sight Institute, Sydney Eye Hospital Campus
Sydney Medical School, the University of Sydney,
Ikramullah
MBBS, M.Phil
(Community Medicine)
Prof. and Head,
Department of Community Medicine, Nowshera Medical College, Nowshera.
Ihsan Ali
MBBS. Trainee Medical
Officer, Department of Ophthalmology, Mardan Medical Complex, Mardan.
Author’s Contribution
Zia Muhammad
Data collection,
Manuscript writing, Critical analysis.
John Grigg
Manuscript review,
critical analysis.
Ikramullah
Data analysis,
manuscript writing.
Ihsan Ali
Data analysis,
manuscript writing.