A New High for Hyperopia

Spectacle correction of hyperopia has been the standard of care for many centuries. Yet many patients who received them were probably asking, “Thank you for helping me see better, doctor, but isn’t there something you can do that doesn’t involve glasses?” The ophthalmology world has listened to these pleas and currently offers an array of effective interventions.

With an estimated prevalence of hyperopia in Europe of 32% among patients 35 to 74 years of age, the demand for treatment is likely to grow. The current options for hyperopia treatment include spectacles and contact lenses, LASIK, PRK, transPRK, kerato-lenticule extraction (KLEx), small incision lenticule extraction (SMILE), phakic IOL implantation, and refractive lens exchange (RLE). Each has its advantages and limitations.

While spectacle correction can be effective in most cases, patients are obliged to wear glasses, maintain and keep track of them, and replace them regularly. Glasses for hyperopia tend to be heavy and come with problems associated with all glasses, such as limited peripheral vision, fogging, and discomfort. Contact lenses, for their part, also offer effective treatment but carry well-known risks of sight-threatening bacterial and fungal infection and significant maintenance and long-term cost issues.

The desire to be spectacle free drives patients to seek other options. LASIK, which has been used to treat hyperopia since the 1990s, involves both hardware and software. A primary advantage is it allows younger patients to maintain accommodation while reducing the need for glasses. Predictability and regression are a concern, along with regular LASIK issues such as glare and halos.

“It seems there is currently a consensus on the limits of LASIK for hyperopia treatment,” Professor Burkhard Dick MD, PhD said. “It is generally agreed the upper limit for hyperopia correction via LASIK is between +4.00 D and +6.00 D, with the exact range depending on factors such as corneal and epithelial thickness, shape, optical zone, model of excimer laser, and the surgeon’s experience. It is advisable to avoid corrections beyond this range, as the risk of undercorrection, regression, and induced aberrations increases, making outcomes less predictable.”

Lenticule extraction procedures, now known under the umbrella term KLEx, have served in myopia treatment for many years, but have only recently been tried as an alternative to LASIK for hyperopia treatment. The recent ESCRS Congress in Barcelona featured the announcement of the first EU approval of a lenticular extraction hyperopia treatment using SMILE pro technology (Zeiss).

There is still debate and discussion about the relative merits of KLEx versus femtosecond-LASIK (FS-LASIK) for hyperopia. The general thought is KLEx may be comparable to FS-LASIK in mild to moderate hyperopia cases, particularly when a flapless procedure is a priority. However, Prof Dick said it is worth noting that FS-LASIK has a more established track record for hyperopia and has been refined over decades.

“Compared to myopic KLEx, KLEx for hyperopia is more challenging for the surgeon because of the different shape and larger diameter of the lenticule requiring the use of a larger patient interface,” he noted. “Still, hyperopic KLEx is a minimally invasive procedure with a lower risk of severe complications compared to intraocular options, which could make it a suitable choice for some patients. As of today, it remains to be seen whether KLEx will have less regression over time due to its greater optical and transition zones.”

Phakic IOL

One possible option for hyperopia is a phakic IOL. In cases where the patient is experiencing moderate to high hyperopia (typically beyond +4.00 D) or when the corneal thickness or shape does not allow for safe laser correction, phakic IOLs may be preferable.

“Phakic IOLs may be an especially attractive option for younger patients with good lens clarity, as phakic IOLs preserve accommodation,” Prof Dick said. “Unfortunately, the anterior chamber depth and configuration in these hyperopic eyes often do not allow implantation of a phakic IOL, especially considering the increasing lens thickness in younger patients over time.”

Refractive lens exchange

Prof Dick suggested refractive lens exchange (RLE) may be the best option for select patients who may not be suitable candidates for other surgical approaches. It carries the same small risks as standard cataract surgery, including infection, capsular rupture, and posterior capsule opacification.

It may also be suitable for hyperopic patients older than 40 to 45 years old, particularly when presbyopia begins to manifest or when the degree of hyperopia exceeds the safety limits for laser or phakic IOL treatments. Those with early cataracts may find it beneficial, Prof Dick explained, as RLE offers a long-term solution by removing the dysfunctional lens and correcting vision in a single procedure.

Please see related articles in this issue for the latest studies on hyperopia treatment.

H Burkhard Dick MD, PhD is Professor of Ophthalmology and Chairman, Ruhr University Eye Hospital Bochum, Bochum, Germany. He is also Secretary of the ESCRS. dickburkhard@aol.com