Choosing refractive correction options for our glaucoma patients is complex. The reasons: Each patient presents with different risk factors, such as ongoing treatments, varying disease severity, and different visual needs. (See Recognize Charles Bonnet Syndrome,” p.30.)

Here, I discuss the options.

GLASSES

The average glaucoma patient is older than age 55.¹ This fact indicates that most glaucoma patients are presbyopic and, therefore, will need some form of refractive correction, be it distance only, near only, or both.

An evaluation of the health of the ocular surface is key to determining the optimum prescription, as ocular surface disease can cause ocular surface instability, which can alter one’s prescription. Glaucoma-related ocular surface disease (G-OSD) affects 40% to 59% of glaucoma patients.² The main cause of G-OSD is anti-glaucoma drops, a proven and popular treatment option for many types of glaucoma and many of which contain preservatives that can create ocular surface instability and related symptoms, such as ocular dryness. G-OSD is also implicated in decreased visual quality and non-compliance to using anti-glaucoma drops due to these side effects, among others such as burning and stinging upon installation. These experiences, in turn, affect enjoyed activities, such as reading and driving. (For a discussion on the diagnosis of ocular surface disease, see “Determine the Root Cause of Dry Eye Disease,” at bit.ly/3G1IcN5 .)

There are two principles in the treatment and management of G-OSD: (1) minimize the effect of glaucoma therapy on the ocular surface, and (2) recognize and treat OSD as early as possible, so a stable refraction can be acquired, and the patient can return to the activities they enjoy. (For more on treatment, see “Heal, Clean, Calm and Protect the Ocular Surface,” at bit.ly/3n3Va6a .)

In terms of specific recommendations, polycarbonate, or safety lenses, can help protect the monocular patient’s eye that retains visual capabilities. For glaucoma patients who experience light sensitivity, which can be quite common, photochromic lenses or a separate pair of tinted glasses can be beneficial.³ Fresnel prisms can help expand the peripheral field in patients who have VF loss.⁴ With the incorporation of horizontal peripheral prisms, patients can expand the field above and below the horizontal meridian, still leaving a vertical gap in the central area for direct, binocular vision for activities like driving. Oblique designs allow for tilting of the bases of both prism segments in the direction of the hemianopia and expanding fields for up to 15.°

LOW-VISION SERVICES

Low vision devices and referrals can be beneficial for patients who have VF loss. Thus, whether you are knowledgeable in low-vision devices and training or refer to a specialist, it’s important to educate glaucoma patients of this option.

As a brief yet related aside, it should be noted that referring a patient to a low-vision specialist can be difficult for both the patient and their family. Stating the reasons for the referral and how it may benefit the patient (e.g., less of a likelihood of falling) helps the patient understand how low-vision services may alter their daily life for the better.⁵

While the patient awaits their low-vision evaluation appointment, I have found it helpful to ask the patient to show me their phone, so I can change their text size and contrast settings, and to provide them with information on phone apps and computer software that can help them while they wait. Applications, such as Seeing AI, SuperVision mini, and Visor, can often aid them in recognizing people, reading labels, and magnifying mail. (For more on low vision, see “Change the Life of a Low Vision Patient,” at https://bit.ly/3t7pLno , and check out PentaVision’s “Managing Low Vision” newsletter at https://bit.ly/3JQ1AzO .)

CONTACT LENSES

Glaucoma patients who have corneal irregularities after undergoing glaucoma surgery can benefit from scleral lenses.⁶ The reasons: They help neutralize corneal irregularities due to their inherent design, and they can be created to minimize bleb interactions and decrease the risk of inflammation or infections of the bleb. Lens customizations, such as notching, truncation, and vaulting of the peripheral curves, can be made to create a customized peripheral landing of the scleral lens.

As scleral lenses rest on the conjunctiva and scleral tissue surrounds the area above aqueous production and drainage, there has been concern about the impact of scleral lenses on IOP.⁷ Further research is warranted and currently being assessed in this area. In the meantime, patients who have glaucoma and wear scleral lenses should be monitored closely for permanent optic nerve damage and VF defects.

Soft contact lens wear in glaucoma patients requires these patients to be mindful of their ophthalmic drop regimen. Specifically, if a patient is on a regimen that involves drop instillation more than twice a day, they must remove their lenses to instill the drops. Additionally, per the FDA, these patients should be advised to wait at least 15 minutes after using drops before placing any type of contact lenses onto their eyes. Something else to consider: Due to glaucoma patients’ advanced age, they are at an elevated risk of developing ocular surface disease, which can be further exacerbated by an anti-glaucoma drop regimen and contact lens wear. If the current or prospective contact lens wearer is opposed to or uncomfortable with the drop-use requirement and/or is unable to prevent OSD via the use of preservative-free topical therapies, selective laser trabeculoplasty can be an effective option, as it can eliminate the need for or decrease the number of drops required for the patient to manage their disease, killing two birds with one stone.

CORNEAL REFRACTIVE SURGERY

Corneal refractive surgery can be favorable for glaucoma patients who would prefer to use glasses or contact lenses as little as possible. As is the case with obtaining an accurate glasses prescription, patients interested in this option should undergo an ocular surface evaluation, as a stable ocular surface is vital in determining an accurate prescription when calculating for corneal and cataract refractive surgeries. Programming and calculating the final outcome for refractive surgery depends on consistent findings, refraction, and topography scans.

In terms of corneal refractive surgery itself, it is important to note that during the flap creation in LASIK procedures, for example, 70% of flaps are created using a femtosecond laser. During this intraoperative part of the procedure, IOP can be elevated anywhere between 65 mmHg to 260 mmHg, putting the optic nerve at risk for damage.⁸ Thus, glaucoma patients interested in this option should be thoroughly educated of this risk.

Something else to consider: Patients who undergo PRK pose an increased risk of glaucomatous damage due to the need for longer post-surgical steroid use. Therefore, these patients should be monitored closely for IOP spikes, or surgeons should consider prescribing soft steroids.⁹ Similar to PRK, both conductive keratoplasty, epi-LASIK, and LASEK do not involve the pressure applied from a femtosecond laser; therefore they pose the same risk of a pressure spike as with those who are steroid responders.¹⁰

REFRACTIVE LENS EXCHANGE (RLE)

RLE can decrease multiple future surgeries and improve visual outcomes with premium IOL options.¹¹ To facilitate the decision process, patients should be presented IOL options before they develop age-related cataract changes. This allows them to understand what changes to expect and what options they have. Also, to reiterate, a stable ocular surface is vital for postsurgical visual outcomes.

For those glaucoma patients who develop cataracts, cataract surgeries are beneficial in lowering IOP post-surgically.¹² While the mechanism is still unknown, lowering the IOP can help patients be less dependent on anti-glaucoma drops, leading to increased quality of life and less medical expense burden. Further, with MIGS now available, glaucoma patients can achieve the dual gains of undergoing cataract surgery sooner than the previously accepted way of waiting until the cataract has “matured.” These benefits also lead to patients prolonging more invasive procedures, such as filtering blebs, and avoiding infections.¹²

The primary concern with any RLE procedure is implanting diffractive technology multifocal IOLs. The reason: They distribute light to land on different ocular focal points, affecting the reliability of VFs and the image quality of the macular OCT.¹¹

PROVIDE REASSURANCE

We must also consider how we present the information to patients on each refractive option. Educating patients without sugar-coating their prognosis, not rushing through conversations, having supportive family members by their side, and explaining disease changes is greatly appreciated. OM

REFERENCES

1. King C, Sherwin JC, Ratnarajan G, Salmon JF. Twenty-year outcomes in patients with newly diagnosed glaucoma: mortality and visual function. Br J Ophthal. 2018;102(12), 1663–1666. doi: 10.1136/bjophthalmol-2017-311595.
2. Nijm LM, de Benito-Llopis L, Rossi GC, Vajaranant TS, Coroneo MT. Understanding the Dual Dilemma of Dry Eye and Glaucoma: An International Review. APJO. 2020;9(6), 481–490. doi: 10.1097/apo.0000000000000327.
3. Otsuka Y, Oishi A, Miyata M, et al. Wavelength of light and photophobia in inherited retinal dystrophy. Sci Rep. 2020;10(1):14798. doi: 10.1038/s41598-020-71707-2.
4. Peli E, Bowers AR, Keeney K, Jung JH. High-Power Prismatic Devices for Oblique Peripheral Prisms. Optom Vis Sci. 2016 May;93(5):521-533. doi: 10.1097/OPX.0000000000000820
5. Khanna A, Ichhpujani P. Low Vision Aids in Glaucoma. J Curr Glaucoma Pract. 2012;6(1):20-24. doi: 10.5005/jp-journals-10008-1104.
6. DeNaeyer G, Sanders DR. Virtual Scleral Lens Fitting over Large Filtering Bleb Using Corneal-Scleral Topography. Int J Ophthalmol. 3(1), 1–5. https://doi.org/10.15226/2474-9249/3/1/00130 .
7. Schornack MM, Vincent SJ, Walker MK. Anatomical and physiological considerations in scleral lens wear: Intraocular pressure. Cont Lens Anterior Eye. 2021 Nov 22;101535. doi: 10.1016/j.clae.2021.101535.
8. Lauzirika G, Garcia-Gonzalez M, Bolivar G, et al. Measurement of the Intraocular Pressure Elevation During Laser-Assisted In Situ Keratomileusis Flap Creation Using a Femtosecond Laser Platform. Transl Vis Sci Technol. 2021;10(3):9.doi: 10.1167/tvst.10.3.9.
9. Katsanos A, Arranz-Marquez E, Cañones R, Lauzirika G, Rodríguez-Perez I, Teus MA. Retinal nerve fiber layer thickness after laser-assisted subepithelial keratomileusis and femtosecond LASIK: a prospective observational cohort study. Clin Ophthalmol. 2018;12:1213-1218. doi: 10.2147/OPTH.S168033.
10. Osman E. Laser refractive surgery in glaucoma patients. Saudi J Ophthalmol. 2011;25(2):169-173. doi: 10.1016/j.sjopt.2010.04.003.
11. Fea AM, Durr GM, Marolo P, Malinverni L, Economou MA, Ahmed I. XEN Gel Stent: A Comprehensive Review on Its Use as a Treatment Option for Refractory Glaucoma. Clin Ophthalmol. 2020;14:1805-1832. doi: 10.2147/OPTH.S178348.
12. Shrivastava A, Singh K. The effect of cataract extraction on intraocular pressure. Curr Opin Ophthalmol. 2010;21(2):118-22. doi: 10.1097/ICU.0b013e3283360ac3.
13. Somoza-Cano FJ, Abuyakoub A, Hammad F, Jaber J, Rahman A, Armashi AR. Nonpsychotic Hallucinations and Impaired Vision: The Charles Bonnet Syndrome. Cureus. 2021;13(8):e16801. doi: 10.7759/cureus.16801.

DR. BHAGAT practices at the TLC Laser Eye Center, in Providence, R.I., where she works alongside Dr. Ezra Galler, a corneal, cataract, and refractive surgeon. She has been published in numerous journals, lectured, and presented at major meetings and CE events, and has volunteered on subcommittees for large optometric organizations.