By the time your patients become presbyopic, most probably have a good idea of the type of treatment they want. Theyve talked to friends and searched the Internet. Hopefully, the type of correction they want will be appropriate for them. Then again, presbyopes often have other conditions that limit their treatment options.
These four cases, which make up our Sixth Annual Presbyopia Report, describe situations in which prescribing treatment was not as straightforward as writing a prescription for progressive addition lenses or fitting multifocal contact lenses. See how these O.D.s found the best and most appropriate treatments for their atypical presbyopic patients.
Case 1: Monovision Glasses?
By Brian Chou, O.D.
Diagnostic data. A 45-year-old male presented with a complaint of decreased near vision. His ocular history was significant for having six-incision radial keratotomy in each eye 15 years ago. The patient reported using +1.25D over-the-counter reading spectacles only for near work. Unaided visual acuity was 20/60 O.D. and 20/20 O.S. Manifest refraction was +2.50 -0.75 x 004 O.D. yielding 20/20, and +0.25 -0.25 x 180 O.S. yielding 20/20. No sighting dominance was exhibited with +1.50 fog. Near testing determined an add of +1.50D. Binocular testing and ocular health evaluation were unremarkable.
Management. I prescribed monovision glasses with +2.25 -0.75 x 004 O.D. (effective add of -0.25 D) and +1.75 -0.25 x 180 O.S. (effective add of +1.50D) using aspheric lenses with an antireflective coating. This patient was happy with his monovision glasses, and noted that he could see much better with them at near than with his +1.25D over-the-counter readers. He enjoyed the ability to see distant targets clearly without removing his prescription glasses, whereas he had to remove his readers to see distant objects.
Discussion. I decided against prescribing bifocals or progressive lenses for this patient due to the optical consequences of anisometropia. Although bifocals or progressives may work in cases like this, anisometropic spectacle correction may cause patient discomfort. One reason is aniseikonia, or a difference of image magnification between the two eyes. If I prescribed the manifest refraction for bifocals or progressive lenses, I would have expected this patient to experience an image size difference of approximately 2% between his eyes.
Although minimizing the vertex distance can help patients tolerate anisometropic spectacle prescriptions by reducing image size differences, the optical consequence of induced prism remains unchecked. With bifocals or progressive lenses, looking downward through the reading area induces prism, and the right eye would see objects lower than the left eye. Any substantial vertical image displacement stresses the vertical compensatory ranges of the eyes, resulting in discomfort. Slab-off prism can counteract the induced prism in downgaze to make anisometropic spectacles comfortable, but it also introduces a cosmetically noticeable line across one of the lenses.
Due to the optical challenges of aniseikonia and induced prism, contact lens correction or refractive surgery are often appropriate alternatives. However, this patient declined such treatments, electing to use glasses instead.
Monovision is not a typical strategy with glasses. However, in selected cases of presbyopic anisometropia, as illustrated here, monovision glasses can circumvent optical problems that may occur with bifocal or progressive lenses.
Pearls on Presbyopes and Spectacle Lenses
Despite advances in contact lens and surgical options, glasses remain the frontline treatment for most presbyopes because they are simple and non-invasive.
Assume that presbyopes want the best lenses. While patients are in the exam room, discuss the benefits of premium ophthalmic lenses, such as high-index, antireflective treatments, aspheric lenses and progressive lenses.
Glasses are not ideal for presbyopes with extremely high prescriptions or significant anisometropia because of undesirable optical effects. In these cases, consider contact lenses or refractive surgery.
Brian Chou, O.D.
Case 2: The Presbyope With Cataracts
By Joseph P. Shovlin, O.D.
Diagnostic data. A 56-year-old male presented with moderate myopia of -5.00D O.U. and presbyopia. His visual acuity was 20/25 O.D. and 20/30 O.S. He informed me that he wanted LASIK to correct his vision. However, like many patients older than age 50 who request refractive surgery, this patient had cataracts.
Management. LASIK is not a good corrective option for some patients older than age 50 because lenticular changes can cause the need for enhancement relatively early in the postoperative course. Some patients in this age group may even undergo enhancements for lenticular changes and then require cataract surgery a few months to years later. Therefore, I informed this patient that LASIK was not the best option for him.
The corrective options that I considered for this patient included:
Lens extraction and implantation of a conventional IOL.
Lens extraction and implantation of a multifocal or bifocal IOL.
Contact lenses and/or spectacles.
The patients acuity dropped significantly to 20/50 with bright light due to his cataracts, so lens extraction seemed to be the most appropriate option. I informed the patient that lens extraction and IOL implantation would be the best treatment option for him and then discussed the limitations of multifocal IOLs. I reviewed the patients expectations and vocational and nonvocational vision requirements. After a thorough discussion, the patient and I agreed that lens extraction and multifocal IOL implantation seemed to be the best option to treat his cataracts and presbyopia.
This patients cataracts were removed, and both eyes were implanted with the AcrySof ReStor IOL (Alcon). The patient did not require any distance correction postoperatively and reported good vision at near. He could easily read at the J2 level.
Discussion. The AcrySof ReStor IOL was considered the most appropriate lens for this patient because it could meet his near vision demands and fit his large pupil size. The acrylic diffractive pattern of this lens is graduated through a proprietary process called apodization. A gradual blend allows distance, intermediate and near vision. The gradual blend also allows for this lens to be implanted in myopic patients who have fairly large pupils. Some night vision problems, especially glare, have been reported with this IOL. However, our patient was happy with his outcome.
Always discuss the limitations of IOLs, especially night vision problems such as glare and distortion, with your patient. Ensure that your patient has realistic expectations and knows that it may take several weeks to months to adapt to and accept the IOL. Patients must also be aware of the possibility of IOL removal and the problems that may accompany such a procedure if they cannot tolerate the IOLs. Providing patients with realistic expectations is a key to them accepting their IOLs.
Case 3: The Former-LASIK Presbyope
By Paul Karpecki, O.D.
Diagnostic data. A 44-year-old male presented with uncorrected vision of 20/20 O.D. and 20/20+2 O.S. His chief complaints were difficulty reading and decreased near vision. Slit lamp examination showed normal lids, clear corneas, deep and quiet anterior chambers and clear lenses. His refraction was -0.25D O.D. and +0.25 -0.25 x 175 O.S. yielding 20/20 +2 O.U. His retinas showed no apparent pathology.
Management. Treatment options to address this patients primary complaint of presbyopia included:
+1.50D reading glasses.
A +1.00D contact lens for his left eye, which is the non-dominant eye, to induce monovision.
Laser correction of +1.00D to improve near/intermediate vision.
NearVision conductive keratoplasty (CK) (Refractec).
IOL implantation with an accommodating IOL or multifocal IOL.
The patient ruled out glasses, stating that he had invested more than $2,000 per eye for LASIK so he would not have to wear glasses. He also ruled out contact lenses because he could not tolerate them prior to LASIK surgery more than four years ago, and he did not want to try them again.
The patients remaining option was a surgical procedure. Lifting the flaps after four years to perform a laser procedure was an option, but it could be difficult to locate the flap edges and lift them. Also, a hyperopic ablation over a relatively small flap diameter from the original myopic ablation (8.5mm) might result in the ablation going past the flap edge. Therefore, the patient and I ruled out this option.
The patient perceived a multifocal IOL procedure as too invasive. Also, he still had some natural accommodative amplitude. The cost was also a deterrent to the patient. Additionally, because the original procedure had induced some higher-order aberrations (i.e., coma and spherical aberrations), a multifocal IOL might induce contrast sensitivity problems.
The patient and I agreed that NearVision CK would be the best treatment option. This decision was made based on the facts that only one eye needed to be treated, NearVision CK could be performed without affecting the original LASIK flap, and the patient would be charged only for an upgrade for this procedure. A test with the phoropter and a +1.00D lens showed minimal loss of distance correction, and the patient was pleased with the near vision.
Patient Selection for Presbyopic Surgery
Non-clinical contraindications to presbyopia surgery include:
Brian Chou, O.D.
I informed the patient prior to his surgery that his presbyopia could progress, and he might require another treatment in his late 40s or 50s. It is important that we inform patients about the progression of presbyopia so they have realistic expectations of the surgery and do not feel as though it failed. Although presbyopia will progress, CK allows for future treatments. With the selection of treatment options available today, O.D.s can typically keep their patients happy by selecting the appropriate treatment based on the patients visual requirements, age and expectations.
Discussion. A laser enhancement is a safe option for presbyopes who have previously undergone myopic LASIK, especially if the original procedure was performed recently. However, if the procedure was performed a long time ago, it is more difficult to lift the flap. Although tearing of the flap is rare, it may occur. Also, the patient may experience more discomfort if the original procedure was performed long ago.
Another consideration: A hyperopic ablation would be used in a LASIK enhancement, so the treatment zone will be large and may be outside of the original flap edge. This could result in patient discomfort, and the refractive results may be different than expected.
Your Role in Comanaging Presbyopia Surgery
Consider whether cataract formation should preclude or postpone surgery.
Be cognizant that many patients older than age 40 will experience conditions such as cataracts, lid disease and dry eye that need to be addressed preoperatively.
Carefully check patients retinal status for various forms of maculopathy, such as pre-retinal fibrosis, early forms of macular degeneration (even occult membranes) and peripheral retinal findings. These conditions could affect surgical outcomes, optometrist Joseph Shovlin says.
Check patients IOP and optic nerves to ensure they are normal.
Ensure that your patients postoperative expectations are realistic. Inform patients that surgery treats presbyopia, but does not reverse or cure it, says optometrist Anthony Verachtert, of Kansas City, Mo.
Inform patients that they may need visual correction postoperatively. Without this understanding, presbyopic patients may incorrectly believe that surgery will provide them with optimal near and distance vision in both eyes, optometrist Brian Chou says.
Counsel patients that they may need to rely on reading glasses for small print and prolonged reading, and in poorly lit environments, Dr. Verachtert says.
If patients will undergo monovision LASIK or CK, have them use contact lenses that simulate monovision before recommending them for a monovision procedure. However, its important to explain that their vision with the lenses is only a simulation and their actual postoperative vision will vary depending on individual responses to treatment, Dr. Chou says.
Ask: How are you enjoying your vision? rather than Are you having any problems? If there are problems, you will find out about them during the clinical exam, or the patient will volunteer information. Theres no need to spoil a good outcome by planting seeds of doubt, Dr. Chou says.
Address refractive issues, such as whether an enhancement is necessary. Keep in mind that as patients approach their mid- to late 40s, part-time spectacle or contact lens correction is likely for LASIK candidates who do not have lenticular opacity. Even when multifocal IOLS are implanted, part-time spectacle correction is not unusual, Dr. Shovlin says.
See patients regularly to monitor for ocular pathology. Examinations should include routine dilation and IOP measurement.
By Joseph P. Shovlin, O.D.
Diagnostic data. A 52-year-old male presented with a chief complaint of difficulty reading. He was currently wearing disposable soft multifocal contact lenses with a myopic prescription of -3.50D O.D. and -4.50D O.S. with a low add in both eyes and a small minus over-correction in his nondominant eye. Prior to his current prescription, he had tried a multifocal contact lens with a high add effect in his left eye but showed minimal improvement in near acuity after a one-week trial.
Management. On this visit, the patient tried a Frequency 55 Bifocal lens (CooperVision) with a +2.00D add in his left eye to attempt to improve his reading performance. His acuity with this lens was J1. This bifocal lens does not provide as much distance vision as other bifocal and multifocal lenses, but the center add can improve near vision for reading. The patients right lens remained the same, and he was able to function well with one multifocal and one bifocal lens.
Discussion. Optometrists should be familiar with the available multifocal and bifocal lenses so they can select the lenses that will best improve their patients distance and/or near acuity. Through clinical experience, I have found that most early presbyopes function well with the multifocal lenses available today.
Some multifocal lenses perform almost equally well at both distance and near up to a certain add power (i.e., about +1.50D). However, I have found that mixing and matching lenses to improve distance or near vision can best accommodate patient needs. Increasing the add power of the lens for the non-dominant eye often helps patients see near and far. Monovision with single-vision lenses in both eyes or a single-vision lens in one eye and a multifocal lens in the other eye is sometimes an option for patients.
Presbyopes who should not wear contact lenses include those with:
Joseph P. Shovlin, O.D.
Dr. Chou practices at Carmel Mountain Vision Care in San Diego. Dr. Shovlin practices at Northeastern Eye Associates in Scranton and Clarks Summit, Pa. He also edits Review of Optometrys Cornea and Contact Lens Q&A column. Dr. Karpecki is the director of research at Moyes Eye Center in Kansas City, Mo. He also edits Review of Optometrys Research Review column.