| FAQs
1. What is glaucoma?
Glaucoma is usually high pressure inside the eye that damages the optic nerve and can result in permanent vision loss.
2. What are the symptoms of glaucoma?
Although certain types of glaucoma may cause pain, redness, haloes, and blurred vision, most people with glaucoma do not experience any symptoms until they have lost a significant amount of vision. This loss of vision is permanent; it cannot be reversed. Because of this, regular eye examinations with an ophthalmologist are very important.
3. What causes high pressure inside the eye?
High pressure inside the eye is caused by an imbalance in the production and drainage of fluid, aqueous humor in the eye). The channels that normally drain the fluid from inside the eye do not function properly or are blocked. This results in an increased amount of fluid inside the eye, thus raising the pressure.
4. My eye pressure is high. Does that mean I have glaucoma?
Normal eye pressure which is measured in millimeters of mercury (mm Hg), ranges from 10-21 mm Hg. When pressure is higher than 21 mm Hg, one is at an increased risk for developing glaucoma. However, in a small %age of individuals one can tolerate pressures slightly higher than normal without developing glaucoma. This is called ocular hypertension.
5. If I have Glaucoma will I go blind now?
No. With constant medication and supervision your remaining vision will be preserved. It is a lifelong process and you have to understand that missing a dose means some loss of vision in the future.
6. Can cataract operation help me with glaucoma?
In some cases it helps but mostly you have to continue with the medication even after the cataract surgery.
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7. How can my child have glaucoma - he is too young?
No age is exempt from glaucoma, right from infancy to old age. We all will work together to make his life comfortable and productive.
8. Is it necessary to take a full medical history as part of the glaucoma evaluation?
It is essential; various systemic diseases and treatment can affect IOP and glaucoma. For example: a β-Blocker may be contradicted for a patient with heart block or asthma. If the patient is taking systemic β-Blockers, a topical β-Blocker will be less effective for lowering IOP and may cause systemic side effects. Some antiglaucoma medications may be contraindicated with certain systemic drugs, For example: MAOIs such as isocarboxazid and phenelzine contradict a2-agonists.
9. I have been diagnosed as Glaucoma suspect. What does that mean?
A glaucoma suspect is a person whom the ophthalmologist feels may have or may develop glaucoma. A Glaucoma suspect may have the elevated pressure inside the eyes or the appearance of the optic nerves may be suspicious. Some people may have pressures that are higher than normal, but they do not develop glaucoma. Other people have optic nerves that might appear to be damaged but, in fact, are actually normal for them
10. Why is the family history of glaucoma important?
Risk for glaucoma increases 5-fold for a patient with a positive family history. First –degree blood relatives are at higher risk.
11. Is migraine associated with NTG (Normal Tension Glaucoma)? Are there other clinically important associations to look for?
Most population- and clinic-based studies have found migraine to be a risk factor for NTG. A migrainous patient may be approximately 21/2 times more likely to progress than a patient without migraine. All glaucoma patients and suspects should be asked about a history of systemic vasospastic diseases (Raynaud’s phenomenon), blood loss, severe hypotension (haemodynamic crisis), and stroke.
12. Do we need to check CCT (Central Corneal Thickness) for all glaucoma patients and suspects?
Ideally, yes. IOP measurement is not precise, and there is no 'correction’ factor to make it accurate.
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13. What is the effect of corneal oedema on IOP measurement?
Corneal oedema can cause the tonometer to read the falsely low. With mild corneal oedema secondary to contact lens wear, the IOP measurement is falsely high.
14. Is the type of musical instrument a patient plays important for the management of Glaucoma?
Playing wind instruments increases IOP considerably by the valsalva manoeuvre increasing episcleral venous pressure. Similarly, a person who performs head-down Asanas (Sirsasana) as part of yoga can have a 2- to 3-fold increase in IOP, Large amounts (≈2l) of fluid intake at a time also raises IOP.
15. Is it necessary to dilate the eye for routine optic disc assessment?
Dilated optic disc examination is ideal. In addition to glaucoma evaluation, the rest of the fundus should be examined for related and unrelated pathology, as several retinal disorders can produce glaucoma-like field defects.
16. If I have glaucoma, how often do I need to be checked?
The frequency of your checkups depends on the severity of your glaucoma. If the glaucoma is extremely mild or if you are a low-risk glaucoma suspect, you may only need to be examined on an annual basis. For more severe glaucoma, examinations may need to be done monthly, or possibly even more frequently, until the glaucoma stabilizes. Once the glaucoma is stable, examinations every 3-6 months are usually appropriate.
17. Can glaucoma be prevented?
Most types of glaucoma cannot be prevented. While vision loss due to glaucoma cannot be recovered, with appropriate treatment, further vision loss can hopefully be prevented. Those types of secondary glaucoma resulting from eye injuries or certain diseases, such as diabetes and uncontrolled hypertension (high blood pressure), may be preventable or even avoidable with certain measures, such as protective eyewear to avoid eye injuries and proper management of diabetes and uncontrolled hypertension. One type of glaucoma, acute angle-closure glaucoma, can sometimes be prevented if a laser procedure is performed prior to its onset. To determine if you are at risk for acute angle-closure glaucoma, you should see an ophthalmologist for an eye examination.
18. What is the role of imaging technologies for optic disc evaluation in the clinic?
Abnormal HRT, GDx, or OCT results alone are not adequate to diagnose glaucoma. Glaucoma diagnosis is based on both structural (optic disc) and functional (VF) changes, along with a patient’s clinical profile. In the hands of an experienced clinician who understands the strengths and limitations of the tests, information is very helpful in clinical situations.
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19. What is the current role of short-wave automated perimetry or blue-on-yellow perimetry in glaucoma management?
Short –wave automated perimetry may demonstrate VF loss up to 5years earlier than standard automated white-on-white perimetry in glaucoma suspects. As glaucoma usually occurs in age groups with nuclear sclerosis, short-wavelength automated perimetry results need careful interpretation.
20. Should the target IOP be calculated for every patient?
In some ways, this is done for every patient, but is not always formally written in the notes. IOP-lowering should be individualized for each patient: an individualized (target) IOP tends to prevent over- or under-treatment and minimizes treatment effects on QOL. There is no definitive evidence for the concept or the methods used to determine a target IOP.
21. Does the target IOP need to be calculated only at the beginning of management?
Target IOP is not a static or magic number, but a range that should change depending on the results of long-term monitoring. If a patient progresses at the target IOP, lower it further. If a patient is stable at the large IOP, perhaps the target could be set to a higher level (with ongoing careful monitoring), allowing withdrawal of same treatment.
22. Do all patients with NTG require systemic evaluation such as brain scan or carotid Doppler test before diagnosing them with NTG?
No. A small proportion of patients with NTG, especially those who are younger, have unilateral disease, disc pallor out of proportion with cupping, a typical VF defects, and colour deficiency, require appropriate cardiovascular and/or neurological investigation.
23. What is the goal of glaucoma management? Is it IOP reduction, prevention of Visual Field progression, or prevention of progression of optic disc damage?
Glaucoma management aims to preserve visual function and QOL for individual patients for their lifetime. The aim is not to treat only the IOP, optic disc, or VF, but to treat the patient as a whole to provide maximum benefit with minimal side effects.
24. With so many drugs available, which one should be used as first-line treatment?
The ideal drug should be effective, easy to use, and affordable, with no systemic side effects, and minimal or no ocular side effects. PGAs are popular as first-line agents. β-Blockers and a2-agonists might be appropriate, especially in countries where costs prohibit expensive drugs.
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25. Can relatively selective β1-blockers (Betaxolol) be prescribed to a patient with asthma?
Even though they are selective and have fewer respiratory side effects, relatively selective β-blockers can worsen asthma, they should be used with caution, if at all. The 'double-DOT’ instillation technique should always be used to minimize systemic absorption.
26. What should be remembered when starting a unilateral trial with a β-Blocker?
Used unilaterally, β-blockers have a contra lateral effect of approximately 1.5 mm Hg; this correlates with the IOP fall in the treated eye and with the baseline IOP in the contralateral eye. Take this into account when assessing the response to the unilateral trial.
27. What is maximal tolerable medical therapy? If a patient who is a business executive and travels a lot can instill only 1 drop per day (he is using a combination of a PGA and a β-blockers), can this be considered as maximal tolerable therapy for him?
Theoretically, maximal tolerable medical therapy is the minimum number and concentration of drug (within the combination of different classes of medications) that provides maximum IOP-lowering for that patient. Practically, it is the greatest burden of drop instillation and a side effect a patient cannot use manage, and is very different for different individuals. If a patient cannot use medications reliably more than once per day then, for this patient, such a regimen mighty be considered maximal tolerable therapy. The patient must be helped to understand the options and risks, and participate in planning realistic treatment strategies.
28. There are numerous generic PGAs available locally. Are they as good as the original molecule?
Most generic PGAs have not been compared with the original molecules. When one latanoprost generic was compared with Xalatan™, the IOP reduction was less than for the original drug. If a generic PGA is used, a unilateral trial should trial should be started.
29. Do fixed combination therapies reduce IOP equally to the individual components?
Medications used individually tend to lower IOP more than if used in fixed combinations. However, fixed combinations are more convenient, encourage adherence, reduce preservative load to the eye, and may be cost-effective.
30. Which antiglaucoma medications can be used during pregnancy?
Direct research into the use of antiglaucoma medications during pregnancy is lacking, limiting the safety evidence.IOP can spontaneously drop later in the pregnancy, so sometimes watching and waiting may be the best strategy.
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31. Is there a significant risk of cataract progression following Laser peripheral iridotomy (LPI)?
There are a few reports of cataract progression following LPI. However there are no definite figures for the increased risk.
32. Is it possible for a patent LPI to become blocked with time? Should the laser opening be checked regularly?
Blockage of a patent iridotomy is uncommon with the YAG laser. Blockage of the LPI or changes in lens thickness can alter angle anatomy. Regular gonioscopy is important.
33. Is it justified to suggest early cataract surgery to a patient with PAC and early visually significant lens changes instead of LPI?
If the cataract is interfering with the patient’s daily activity then early cataract surgery is an acceptable alternative to a YAG LPI. The type of surgery undertaken will also depend on the extent of closure.
34. If a patient with glaucoma who is stable and well controlled with a single medication or fixed combination develops visually significant cataract, should cataract surgery alone be planned ,or should it be combined with filtering surgery?
Either option is acceptable; consult with the patient. Take into account the greater risks with the addition of glaucoma surgery, whether the patient had significant QOL issues with medication, could afford therapy, and was willing to continue to use medication indefinitely.
35. Do glaucoma medications need to be stopped prior to cataract surgery?
Pilocarpine and Latanoprost family drugs disrupt the blood - aqueous barrier. They could be withdrawn approximately 1 week preoperatively and resumed 4 to 6 weeks later (once signs of inflammation have disappeared ).Alternative agents may need to be considered for the period .Evidence for which agents to stop and for how long is lacking.
36. Is it mandatory to perform a YAG LPI before cataract/glaucoma surgery in a patient with PACS, PAC, acute PAC, or PACG?
No. Be aware of the increased risk for ciliary block glaucoma in such eyes.
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37. What is the effect of cataract surgery in eyes with a functional glaucoma filter?
A functioning filter has an increased risk of failure after cataract surgery. If the interval between Glaucoma surgery (trabeculectomy) and cataract extraction is less than 6months, the failure rate is highest.
38. Do patients who have undergone Glaucoma surgery and are stable need to undergo regular follow-up examinations?
Any patient with glaucoma requires regular monitoring. Glaucoma surgery may not adequately control IOP for a patient’s lifetime. Periodic follow-up is required for detection of both progression and long-term complications of surgery.
39. Should first-degree relatives of patients with POAG and PACG be advised to undergo an eye examination? If the examination is normal, how often should follow-up be advised?
A family history of glaucoma is an important predictive risk factor. Depending on the clinical findings, the frequency of regular follow-up ranges from annually to every 2 to 5 years after the age of 35 years.
40. What is the best method to confirm glaucoma progression? What is the role of imaging technologies to detect progression?
Optic disc photography probably detects progression at the earliest stage. Available statistical programmes such as the GPA and newer metrics (Visual Field Index) for the Humphrey field analyser help detect progression. New programmes are also being developed. In early glaucoma (or preperimetric glaucoma), imaging technologies can be helpful to detect progression. Initiation or change of treatment should be made in combination with the clinical picture. Imaging technologies should not be used in isolation, but as part of the assessment.
41. What is the role of patient education in the treatment of glaucoma?
Patient education is most important for glaucoma management. The patient should be an informed participant in the treatment programme. The clinician should explain the disease and its severity, present realistic expectations of treatment outcomes, possible effects of both medical and surgical treatment, and note the patient's preferences. This is an ongoing process; the patient should be kept informed about the course of the disease throughout follow-up.
42. There is a lot of undiagnosed glaucoma in the region around the clinic; therefore screening the local population may be beneficial. Is there a single screening test that can be used to diagnose glaucoma?
There is no single screening test to diagnose glaucoma, which is one of the reasons why 'screening' for glaucoma is not really possible. It is often difficult to be sure about the diagnosis, and the reliability of each test is variable.
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