Ask an Expert about Glaucoma

Thank you for your question. Without having examined your eyes myself, or having seen the notes from your previous exams or tests, it is really difficult to tell you what regimen or goal pressures I would recommend. It sounds as though your right eye has had quite a complex history. In the setting of a retinal detachment, the prognosis for good vision often depends both on how large the detachment was, the mechanism that caused the detachment, and whether or not the retina came off the area that gives the best vision (i.e., the macula. We often call these “macula-on retinal detachments” when the macula is still attached or “macula-off retinal detachments” when the macula has also detached). In the case of a macula-off retinal detachment, the prognosis for good central vision is often much more guarded than if the macula stays attached. In addition, any area that was detached can also have poor vision even after being re-attached. In your case, the area where you have good peripheral vision may have actually stayed attached and that is why you are seeing relatively well in that area compared to others. The second thing to recognize is that once vision is lost from glaucoma, there is a very low likelihood that vision will be regained after getting the pressure under control.

The goal of eye doctors is to lower the pressure enough that the vision does not continue to deteriorate. So, given the fact that you say there is no improvement in your vision, I would suggest that is expected, and the good news is that you do not sound as though you have had progressive loss of vision. It sounds as though your doctors have done a good job of getting your pressure lowered (i.e., around 14) and stopped or slowed the progression of vision loss from glaucoma significantly.

The best precaution that you can take is to have regular eye exams by a glaucoma specialist and continue your current medications to ensure that you achieve your target goal pressure. To achieve this goal, there are essentially three different tools that glaucoma specialists can use to help lower the pressure: eye drops, laser treatments, and surgical methods. The doctors will then follow the intraocular pressure, vision, visual fields, and the appearance of the optic nerves after the new treatment is started. If there is evidence of glaucoma progression, then more drops, more laser treatments, or more surgery will be necessary to lower the eye pressure even more. In the majority of patients, it is possible to lower the pressure enough to stop or dramatically slow the loss of vision; but this may take multiple surgeries, lasers, or medicines (and likely a combination of these three).

As for your second question, Travacom is a combination of two different drugs: Timolol and Travaprost (a beta blocker and prostaglandin analog, respectively). I will list the side effects for each medication as listed in the package insert; however, this comes with one large caveat. You must be very careful when reading package inserts. Often it is difficult to determine whether or not a side effect was caused by the medication itself or if they simply had a side effect (i.e., headache) for another reason at the time they were in the clinical trial testing the drug. As an example, many drugs list colds or upper respiratory tract infections as a potential side effect of a medication in 5-10 percent of the population. I can tell you that I do not believe many of these drugs will cause 5-10 percent of people to get a cold. If a patient is enrolled in the study during the winter months and happens to get a cold during the time that they are enrolled in the clinical study, it must be listed as a side effect regardless of the cause (those are the FDA rules). They may have children in daycare and a cold is being passed around. That is the likely reason, but because they are in the study, the cold must be listed as a potential side effect. So the side effects for Timolol and Travaprost are listed below with my explanation of some of the wording in CAPITAL LETTERS and in parentheses. All information was taken from Drugs.com and the package insert:

Travaprost:

The most common adverse reaction observed in controlled clinical studies with TRAVATAN (travoprost ophthalmic solution) 0.004% and TRAVATAN Z® (travoprost ophthalmic solution) 0.004% was ocular hyperemia (REDNESS OF THE WHITE PART OF THE EYE) which was reported in 30 to 50% of patients. Up to 3% of patients discontinued therapy due to conjunctival hyperemia. Ocular adverse reactions reported at an incidence of 5 to 10% in these clinical studies included decreased visual acuity, eye discomfort, foreign body sensation, pain and pruritus (ITCHING).

Ocular adverse reactions reported at an incidence of 1 to 4% in clinical studies with TRAVATAN® (travoprost) or TRAVATAN (travoprost) Z® included abnormal vision, blepharitis (KIND OF LIKE DANDRUFF OF THE EYELASHES), blurred vision, cataract, conjunctivitis, corneal staining, dry eye, iris discoloration, keratitis (CORNEA INFLAMMATION), lid (EYELID) margin crusting, ocular inflammation, photophobia (SENSITIVITY TO LIGHT), subconjunctival hemorrhage (BREAKAGE OF A BLOOD VESSEL BETWEEN THE SCLERA/WHITE PART AND THE CONJUNCTIVA COVERING THE SCLERA) and tearing.

Nonocular adverse reactions reported at an incidence of 1 to 5% in these clinical studies were allergy, angina pectoris (CHEST PAIN), anxiety, arthritis, back pain, bradycardia (SLOW HEART RATE), bronchitis, chest pain, cold/flu syndrome, depression, dyspepsia (UPSET STOMACH), gastrointestinal disorder, headache, hypercholesterolemia (HIGH CHOLESTEROL), hypertension (HIGH BLOOD PRESSURE), hypotension (LOW BLOOD PRESSURE), infection, pain, prostate disorder, sinusitis, urinary incontinence and urinary tract infections.

Timolol:

The most frequently reported adverse experiences have been burning and stinging upon instillation (approximately one in eight patients). The following additional adverse experiences have been reported less frequently with ocular administration of this or other timolol maleate formulations:

BODY AS A WHOLE: Headache, asthenia/fatigue, and chest pain. CARDIOVASCULAR: Bradycardia (SLOW HEART RATE), arrhythmia, hypotension (LOW BLOOD PRESSURE), hypertension (HGH BLOOD PRESSURE), syncope (FAINTING), heart block, cerebral vascular accident (STROKE), cerebral ischemia, cardiac failure, worsening of angina pectoris (CHEST PAIN), palpitation, cardiac arrest, pulmonary edema (FLUID IN THE LUNGS), edema (FLUID IN THE BODY), claudication (MUSCLES TIRED/CRAMPING), Raynaud's phenomenon (FINGERS/TOES TURN BLUE IN THE COLD), and cold hands and feet. DIGESTIVE: Nausea, diarrhea, dyspepsia (UPSET STOMACH), anorexia, and dry mouth. IMMUNOLOGIC: Systemic lupus erythematosus. NERVOUS SYSTEM/PSYCHIATRIC Dizziness, increase in signs and symptoms of myasthenia gravis, paresthesia (NUMBNESS/TINGLING), somnolence (SLEEPINESS), insomnia (INABILITY TO SLEEP), nightmares, behavioral changes and psychic disturbances including depression, confusion, hallucinations, anxiety, disorientation, nervousness, and memory loss. SKIN Alopecia (LOSS OF HAIR) and psoriasiform rash or exacerbation of psoriasis. HYPERSENSITIVITY Signs and symptoms of systemic allergic reactions, anaphylaxis, including angioedema, urticaria, and localized and generalized rash. RESPIRATORY Bronchospasm (predominantly in patients with pre-existing bronchospastic disease), respiratory failure, dyspnea (SHORTNESS OF BREATH), nasal congestion, cough and upper respiratory infections. ENDOCRINE Masked symptoms of hypoglycemia (LOW BLOOD PRESSURE) in diabetic patients (see WARNINGS). SPECIAL SENSES Signs and symptoms of ocular irritation including conjunctivitis (REDNESS OF THE EYE), blepharitis (DANDRUFF OF THE EYELID), keratitis (CORNEA IRRITATION), ocular pain, discharge (e.g., crusting), foreign body sensation, itching and tearing, and dry eyes; ptosis (DROOPY EYELID); decreased corneal sensitivity; cystoids macular edema (RETINAL SWELLING); visual disturbances including refractive changes and diplopia (DOUBLE VISION); pseudopemphigoid; choroidal detachment following filtration surgery (see PRECAUTIONS, General ); and tinnitus (EARS RINGING). UROGENITAL Retroperitoneal fibrosis, decreased libido, impotence and Peyronie's disease.

The following additional adverse effects have been reported in clinical experience with ORAL timolol maleate or other ORAL beta-blocking agents and may be considered potential effects of ophthalmic timolol maleate: Allergic: Erythematous rash, fever combined with aching and sore throat, laryngospasm with respiratory distress; Body as a Whole: Extremity pain, decreased exercise tolerance, weight loss; Cardiovascular: Worsening of arterial insufficiency, vasodilatation; Digestive: Gastrointestinal pain, hepatomegaly, vomiting, mesenteric arterial thrombosis, ischemic colitis; Hematologic: Nonthrombocytopenic purpura; thrombocytopenic purpura, agranulocytosis; Endocrine: Hyperglycemia, hypoglycemia; Skin: Pruritus, skin irritation, increased pigmentation, sweating; Musculoskeletal: Arthralgia, Nervous System/Psychiatric: Vertigo, local weakness, diminished concentration, reversible mental depression progressing to catatonia, an acute reversible syndrome characterized by disorientation for time and place, emotional lability, slightly clouded sensorium, and decreased performance on neuropsychometrics; Respiratory: Rales, bronchial obstruction; Urogenital: Urination difficulties.

As you can see, this is an exhaustive list; however, many of these side effects may not be associated with the medication directly; however because they happened to a patient during the study period it has to be listed. If you are concerned about a certain symptom, I suggest asking your doctor about that specific symptom to see if the medication causes it. I wish you the best of luck.

On the prescription insert, I noticed a reversal of 2 inactive ingredients, but when I contacted the pharmacist they said there was no labeling law requiring quantitative order on inactive ingredients for prescription drugs. The ophthalmic assistant thought there might be a change in the amount of buffers added in the generic form of the drug. I would like your opinion on this.

Thank you for your question. This is actually a  question that we run into more than most people think. While a pharmacist  is likely the best person to ask regarding the active and inactive ingredients  in “name brand” vs. “generic” drugs and the laws regulating generic drug  production (understanding these complexities is really what pharmacists  specialize in), I can tell you that in my experience the pharmacist and the  ophthalmic assistant are likely correct. I believe that the active  ingredient dosage (and possible bioavailability (i.e., the amount absorbed into  the body) has to be within a certain percentage of the original “name brand”  before the “generic” gets FDA approval. However, I do not think there are  regulations regarding the inactive ingredients used to stabilize the  drug. This often means that the buffers, preservatives, and/or additives  can be quite different. The side effects that we see with medications are  sometimes related to the active ingredient; however in many cases they are  actually related to the inactive ingredients. One of the biggest problems  that we have is with the preservative used in each medication. For  instance, some medications use benzalkonium chloride (BAK) as a preservative,  but in several people this preservative can cause redness, itching, tearing,  the feeling of sand in the eye, etc. In those cases, I often recommend  that the patient return to using the name brand medication that had been  working well in the past because it likely does not have the inactive  ingredient that is causing problems. Generics often work well for most  people, but in some cases, patients definitely see a change in either the  effectiveness of the medication or a change in the side effects once they  change. It is important to let you doctor know if you notice any changes  when moving from a name brand to a generic drug and also make a follow-up  appointment after you start using any generic drug to make sure that it is  still as effective. I wish you the best of luck.

That is a great question. The answer often depends on the doctor doing the surgery. If possible, I will often times have my patients stop their prostaglandin analog (Xalatan, Travatan, Lumigan, or generic) a few days prior to cataract surgery because of a slight increased risk of swelling in the retina (called cystoid macular edema) after cataract surgery when you are on those medications.

Often the choice of whether or not to restart the medication after surgery is dependent on what the pressure in the eye is after cataract surgery. There has been some interesting new data that shows there is an approximate 2 mmHg drop in intraocular pressure that lasts for about two years after cataract surgery (there is not a full understanding of why this happens, but many researchers are currently looking into it). If the pressure has dropped sufficiently after the cataract surgery, it may not be necessary to restart the prostaglandin analog (Xalatan in your case) unless the pressure goes up again above your goal intraocular pressure. In other cases, even if there is a small drop in pressure, it may not be low enough to achieve your goal intraocular pressure, so the doctor will likely restart all of the glaucoma medications after a certain time period after surgery. Again, this is all dependent on the doctor's preferences and how your eye responds to the cataract surgery. Keep your regularly scheduled appointments and the doctor will monitor your pressure and make adjustments to your glaucoma medications accordingly. I wish you the best of luck

The neurologist informed her that her vision will be normal very soon and that the adverse effects were drug induced. She still has some burning and irritation from the nerve disorder, and is worried about her long-term vision. Thank you for your thoughts.

Thank you for your question. Unfortunately, this is likely a question best answered by a neurologist or a neuro-ophthalmologist who specializes in disorders of the optic nerve (other than glaucoma). The glaucoma problem is my area of expertise, but in this case it appears that the change in vision was likely related to something other than the glaucoma. I will try to add a bit of clarity to the situation, but again realize this is definitely not my area of expertise.

My guess is that your relative had what we call “trigeminal neuralgia” or “post herpetic neuralgia.” There are multiple nerve branches around the face and the nerve carries both sensory and motor function. Methylcobalamine is a vitamin B12 derivative. It is primarily used to help treat peripheral neuropathies. Gabapentin is a gama amino butyric acid analog and can be used to treat a few different neurological disorders including seizures, neuropathic pain (trigeminal neuralgia/post-herpetic neuralgia, etc.), and possibly hot flashes. Carbamazepine is a drug that can be used to treat a number of disorders, including neuropathic pain (trigeminal neuralgia), seizures, bipolar disorder, and schizophrenia. Finally, amitriptyline can be used to treat neuropathic pain (post-herpetic neuralgia) but again can be used to treat other disorders such as depression, anxiety, attention deficit disorder, and bipolar disorder.

As you can tell, each of these drugs is used to treat neuropathic pain such as your relative had; however, the drug can also be used to treat other central nervous system disorders. As a result, even though you are only trying to treat the pain sensation coming from the nerve, there can be other side effects because the drug can get into the brain and affect those nerve cells as well. This is probably why your relative became sleepy and had some changes in vision. The good news is that upon stopping the medication the symptoms appear to be resolving.

Post herpetic neuralgia and/or trigeminal neuralgia can be quite painful and can be chronic conditions. It is likely a good idea to see a medical doctor that specializes in treating chronic pain (often anesthesiologists, physical medicine and rehabilitation doctors, or neurologists will do fellowship training in chronic pain management). I suggest consulting with a pain management specialist and then having them work with the glaucoma specialist to determine whether or not there are any visual side effects from the medication.

Obviously, from a glaucoma standpoint, regardless of the treatment necessary for treating the pain, your relative will need to continue maintaining control of the intraocular pressure to prevent further vision loss. I am sorry that I could not give you a more definitive answer, but hopefully this at least points you in the correct direction in terms of finding the appropriate treatment for the pain. I wish the best of luck to your relative.

Thanks for your question. Of course it is difficult without examining you to tell if you should have SLT, but I can address your questions about eye pressure rises after SLT. While I certainly always warn patients of this risk when I talk with them about this procedure, it is generally infrequent, on the order of 3 - 5 percent, and it is not usually sustained. I have heard a few anecdotal cases of sustained eye pressure rises requiring surgery, but these situations are uncommon. There are also several maneuvers your ophthalmologist can do to minimize the risk of an eye pressure spike with SLT. I always give my patients a drop of apraclonidine (or brimonidine) before the procedure to reduce the risk of an eye pressure increase. I titrate the laser power so that I am using the minimum amount of energy to achieve an effect. I usually treat 360 degrees of the drainage system, but some ophthalmologists will only treat 180 degrees to minimize an eye pressure spike, although to my knowledge this has not been definitively shown to be of benefit. I also always have my patients wait 30 – 60 minutes after the procedure so that I can re-check the eye pressure. If there has been a spike, we control it with medications and then re-check the pressure again. Of course, one must weigh the risks and benefits of laser surgery, but I would say that overall SLT is a relatively safe procedure. I have not discussed all of the side effects of the procedure here, but you should have a conversation with your surgeon about the risks, benefits, and side effects before you proceed.

My first inclination is to tell you that cataract surgery is an elective procedure, so if you do not feel that your quality of life or driving is being affected, I would not necessarily recommend the procedure. I am assuming that your left eye has good vision, and while state driving requirements differ, if you have good vision when both eyes are open, you should pass your driver's license test. I am not sure why you are not able to accept an artificial lens as that sounds rather unusual. It may be worth seeking the opinion of a cornea and anterior segment surgery specialist, as there are other types of artificial lenses that can be implanted. It is true that your cataract surgery may be more high risk to perform, so that makes it even more important that you feel ready for surgery and understand the risks. In addition, I do not think your doctor is recommending simply removal of the cataract without replacement of the lens, so you should speak with him or her about how the lens will be replaced. Lastly, you did not comment on whether you have glaucoma and whether it is well-controlled, but that is another factor to consider as well.

Thanks for your question. I think a lot of patients run into your dilemma. The reason that Xalatan is dosed at bedtime is because it begins working 3-4 hours after instillation, peaks at 8 -12 hours, and persists for 24 hours. Because we know that eye pressure is highest in the morning, taking the drop at bedtime puts you in a situation in which the drug is most likely to be peaking at the time when the eye pressure is also peaking. The most important thing is for you to be consistent about taking your drops, so if it is easiest for you to remember to put them in right before you go to bed, then that is what I would recommend. If, however, you know that you will not be going to bed until midnight or later, and you can remember to take the drops around 9 p.m., then it is reasonable to do schedule it then. Alternatively, if you go to bed at 8 p.m., I would not set an alarm clock to wake yourself up and take the drop at 10 in the evening! I hope this helped to answer your question.

Thanks for your interesting question. I am not aware of any interaction between the flu shot and eye pressure or glaucoma. However, there are well-documented, although uncommon, side effects of the influenza vaccine, including fever, aches, breathing problems, and sore, red, itchy eyes. One of these very rare eye side-effects (called oculo-respiratory syndrome) was noted in Canada (2000 - 2001) in association with influenza vaccine from one manufacturer. The patients who were affected had an allergic conjunctivitis/red eye (which resolved), but had normal eye pressures. For more information, read a commentary on this side effect and the original scientific report. My advice is that if you have previously had the flu shot and not experienced side effects, then it should be safe to get it again this year.