PterygiumNCT00563277
Surgical Treatment of Concurrent Cataract and Primary Pterygium
A study testing combined pterygium and cataract operation and pterygium excision followed by cataract operation in people with Pterygium and Cataract, run by Hospital Authority, Hong Kong at 3 sites in China.
Trial summary
Pterygium is known to induce with-the-rule astigmatism. The corneal curvature along the long axis of the pterygium body is flattened. The excision of pterygium will result in steepening of the cornea and reduction of astigmatism. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Pterygium, Cataract, Lenses, Intraocular
- What is being tested?
- combined pterygium and cataract operation and pterygium excision followed by cataract operation
- Type of treatment
- Surgery or procedure
- How many people
- 75 participants
- Where
- 3 sitesChina
- Study dates
- Oct 2004to Dec 2006
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- Adult, Older adult
Who may be able to join
- >18 years old
- Primary pterygium > 2mm across corneal limbus [Measurement made from the imaginary line of surgical limbus to the most advance edge of the visible pterygium tissue] Concurrent visually significant cataract ( BCVA < 20/70 )
- Informed consent for both pterygium and cataract surgery
Who cannot join
- Temporal pterygium
- Double headed pterygium
- Previous ocular surgery in which conjunctival-limbal graft is not feasible
- Pterygium covering visual axis that preclude keratometric assessment
- History of scleritis or autoimmune diseases
Trial locations and contacts
3 sites in 1 country.
China3 sites, 3 recruiting
- Recruiting
Alice Ho Miu Ling Nethersole Hospital
Hong Kong
- Recruiting
Hong Kong Eye Hospital
Hong Kong
Dennis Lam, Prof
- Recruiting
Prince of Wales Hospital
Hong Kong
Alvin Young, Dr
Gloria Leung, Dr
About this study
Official title: Surgical Treatment of Concurrent Cataract and Primary Pterygium: A Randomized Control Trial
Pterygium is known to induce with-the-rule astigmatism. The corneal curvature along the long axis of the pterygium body is flattened. The excision of pterygium will result in steepening of the cornea and reduction of astigmatism. Therefore, the effect of pterygium excision on intraocular lens (IOL) power calculation has been examined in our previous study. The study confirmed that pterygium can cause alteration of IOL power.
The determination of IOL power for cataract surgery is usually calculated from IOL formula called SRK II formula. IOL power = A - (2.5 x AL)-(0.9 x K). Variable A denotes the A-constant of the intraocular lens which is dependent on the IOL material and refractive index. Other variables for input include axial length (AL) and keratometry (K). A larger K reading will result in a lower estimated IOL power and vice versa. Previous studies have documented simultaneous cataract and pterygium operation resulted in reasonable visual outcome without adjustment of IOL power.
Read more
With the presence of a pterygium, the cornea is flattened and lead to a reduction of K value and over-estimation of calculated IOL power. This randomized controlled trial is designed to compare the refractive outcomes of sequential and simultaneous pterygium and cataract operation.
Pterygium excision should be done with various adjuvant therapies to minimize recurrence. Our previous studies reliably demonstrated limbal conjunctival graft and mitomycin C were effective methods to achieve low pterygium recurrence. We use limbal conjunctival autograft as the adjuvant therapy in the current study because this method is safer to be performed either alone or in combination with phacoemulsification. We avoid using mitomycin C as the adjuvant therapy in order to minimize the possibility of intraocular toxicity due to seepage.
- Conditions
- Pterygium, Cataract, Lenses, Intraocular
- Being tested
- combined pterygium and cataract operation, pterygium excision followed by cataract operation
- Keywords
- Pterygium, Cataract, Intraocular lens power calculation accuracy
- Medical subject headings
- Pterygium, Cataract
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
combined pterygium and cataract operationProcedure or surgery
pterygium excision followed by cataract operationProcedure or surgery
What is being measured
The primary outcome is the main question the study is designed to answer.
final refraction deviation from target
Measured: 1 and 3 months post cataract operation
Secondary outcomes (1)
change of IOL power from pre-pterygium estimated power
Measured: 1 and 3 months post pterygium excision
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted26 Nov 2007 (estimated)
- Study startOct 2004
- Study completionDec 2006 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for PterygiumStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 75 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Hospital Authority, Hong Kong
- Sponsor type
- Other government
- Investigators
- Lulu Cheng, Dr, Principal investigator, Department of DOVS, Prince of Wales Hospital/ The Chinese University of Hong Kong
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT00563277
- Sponsor's protocol ID
- CRE-2004.274-T
- Other IDs
- HARECCTR0500012
- Status last verified
- Jul 2010
- First submitted
- 21 Nov 2007
- Last updated
- 7 Jul 2010
- Results posted
- No
Study at a glance
From the registry record, last updated by the sponsor on 7 Jul 2010. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Surgical Treatment of Concurrent Cataract and Primary Pterygium: A Randomized Control Trial
- ClinicalTrials.gov ID
- NCT00563277
- Acronym / sponsor ID
- CRE-2004.274-T
- Conditions
- Pterygium, Cataract, Lenses, Intraocular
- Keywords
- Pterygium, Cataract, Intraocular lens power calculation accuracy
- Study type
- Interventional
- Recruitment status
- Unknown status
- Enrolment
- 75 participants (estimated)
- Lead sponsor
- Hospital Authority, Hong KongOther government
- Study start
- Oct 2004
- Study completion
- Dec 2006 (estimated)
- First posted
- 26 Nov 2007 (estimated)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Pterygium is known to induce with-the-rule astigmatism. The corneal curvature along the long axis of the pterygium body is flattened. The excision of pterygium will result in steepening of the cornea and reduction of astigmatism. Therefore, the effect of pterygium excision on intraocular lens (IOL) power calculation has been examined in our previous study. The study confirmed that pterygium can cause alteration of IOL power.
The determination of IOL power for cataract surgery is usually calculated from IOL formula called SRK II formula. IOL power = A - (2.5 x AL)-(0.9 x K). Variable A denotes the A-constant of the intraocular lens which is dependent on the IOL material and refractive index. Other variables for input include axial length (AL) and keratometry (K). A larger K reading will result in a lower estimated IOL power and vice versa. Previous studies have documented simultaneous cataract and pterygium operation resulted in reasonable visual outcome without adjustment of IOL power.
With the presence of a pterygium, the cornea is flattened and lead to a reduction of K value and over-estimation of calculated IOL power. This randomized controlled trial is designed to compare the refractive outcomes of sequential and simultaneous pterygium and cataract operation.
Pterygium excision should be done with various adjuvant therapies to minimize recurrence. Our previous studies reliably demonstrated limbal conjunctival graft and mitomycin C were effective methods to achieve low pterygium recurrence. We use limbal conjunctival autograft as the adjuvant therapy in the current study because this method is safer to be performed either alone or in combination with phacoemulsification. We avoid using mitomycin C as the adjuvant therapy in order to minimize the possibility of intraocular toxicity due to seepage.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Age groups
- Adult, Older adult
Key inclusion criteria (3 listed)
- >18 years old
- Primary pterygium > 2mm across corneal limbus [Measurement made from the imaginary line of surgical limbus to the most advance edge of the visible pterygium tissue] Concurrent visually significant cataract ( BCVA < 20/70 )
- Informed consent for both pterygium and cataract surgery
Key exclusion criteria (5 listed)
- Temporal pterygium
- Double headed pterygium
- Previous ocular surgery in which conjunctival-limbal graft is not feasible
- Pterygium covering visual axis that preclude keratometric assessment
- History of scleritis or autoimmune diseases
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| combined pterygium and cataract operation | Procedure or surgery | – |
| pterygium excision followed by cataract operation | Procedure or surgery | – |
Primary outcome
final refraction deviation from target
Time frame: 1 and 3 months post cataract operation
1 secondary outcome
change of IOL power from pre-pterygium estimated power
Time frame: 1 and 3 months post pterygium excision
Results and safety
Results are not available in the source record.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 7 Jul 2010.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Lulu Cheng, Dr principal investigator
Department of DOVS, Prince of Wales Hospital/ The Chinese University of Hong Kong
3 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing combined pterygium and cataract operation and pterygium excision followed by cataract operation in people with Pterygium and Cataract, run by Hospital Authority, Hong Kong at 3 sites in China.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 5 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: status not confirmed, as of the sponsor's last update on 7 Jul 2010. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 3 sites in China. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
Results are not available in the source record.
How can a doctor refer a patient or contact the research team?
Contact Lulu Cheng, Dr ((852) 2632 2878, chenglu@i-cable.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
final refraction deviation from target (time frame: 1 and 3 months post cataract operation). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 7 Jul 2010.