Gas-permeable lens provides relief, improves vision in ocular surface disease, keratoconus patients

The lens was well-tolerated in eyes intolerant of rigid lenses and offered pain relief in cases of severe dry eye.

The SPOT gas-permeable scleral lens could benefit keratoconus patients who are intolerant of traditional rigid lenses, according to a study presented at the meeting of the French Society of Ophthalmology in Paris. According to another presentation, it can also provide effective pain relief to patients with severe ocular surface disease.

The large, 17- to 23-mm diameter lenses are filled with balanced salt solution and placed on the eye using a vacuum. They rest on the bulbar conjunctiva and vault over the cornea, creating a smooth liquid overlay that optically neutralizes corneal surface irregularities. Fluorescein staining ensures that an adequate level of tear exchange is maintained. The reservoir also functions as a liquid bandage that protects the corneal surface from air and friction, reducing the symptoms associated with ocular surface disease.

Keratoconus

A single-center, noncomparative, retrospective and prospective study was carried out between January 2002 and February 2009 at the University Hospital of Rouen, France, to evaluate the safety and efficacy of the SPOT scleral lens (Laboratoire D’Appareillage Oculaire) in keratoconus patients.

“The aim of our study was to find out if this lens could be a feasible alternative to the surgical treatment of keratoconus in patients intolerant of gas-permeable rigid contact lenses or for whom a suitable contact lens geometry could not be found,” Bénédicte Brousseau, MD, said.

A total of 32 eyes of 18 patients, predominantly men, were included. Mean age was 42 years. The study was retrospective for 14 patients and prospective for four. Keratoconus was stage 2 in 12 cases and stage 3 in 20 cases. Mean keratometry was 50 D, with a maximum of 62 D, and the thinner pachymetry was 366 µm. The mean follow-up was 22 months.

“A significant visual acuity improvement was obtained in 28 eyes, while four eyes were stable. The mean gain was from 20/60 before to 20/25 after fitting of the lens. All patients were able to adapt to the lens, and no case of intolerance or other complications was reported,” Dr. Brousseau said.

Quality of life, assessed with the National Eye Institute Visual Function Questionnaire-25, was significantly improved. All subscale scores, including self-reported limitations with social functioning and dependency on others, improved in all the patients.

“The lens allowed these patients to postpone or avoid corneal transplantation and its potential complications. None of the patients had surgery during the follow-up. In the retrospective series, some patients were fitted with the lens back in 1995. In these patients, keratoplasty was delayed by 15 years,” Dr. Brousseau said.

Ocular surface disease

In a study carried out at the University Hospital of Marseille, France, the lens was used in 14 patients with ocular surface inflammation of various origins that led to severe dry eye and pain.

“All these patients were challenged by severe pain and vision loss, experienced psychological suffering and were impaired in daily tasks, work and social activities,” Gwenäelle Touvron, MD, said.

The patients wore the scleral lens for an average of 12 hours per day, ranging between 6 and 16 hours. Vision improved by a mean of three lines, and pain, discomfort and photophobia decreased significantly.

The Bausch + Lomb OSD-QoL questionnaire was used to assess quality of life. Overall satisfaction with the lens was 61%, “because the patients knew this was a palliative and not a curative treatment,” Dr. Touvron said. However, everyday life improved significantly, and all patients reported feeling better emotionally and psychologically.

“They regained a smile and were no longer so afraid of the future,” she said.

Some difficulties were experienced in manipulating and fitting the lens, particularly with older patients. The lens, Dr. Touvron said, requires highly motivated patients who are prepared to go through a learning curve for fitting with specialized consultations and a process of adaptation that is sometimes long.

These lenses have limited availability and are expensive. They require custom-tailored construction and are available only in a few centers in Europe, the U.S. and Canada. – by Michela Cimberle

• Bénédicte Brousseau, MD, can be reached at CHU de Rouen, 1 rue de Germont, 76000 Rouen, France; 33-6-22608892; e-mail: benedictebrousseau@hotmail.com.
• Gwenäelle Touvron, MD, can be reached at CHU de Marseille, Hôpital Nord, 13015 Marseille 15, France; 33-4-91964194; e-mail: gwen_touvron@hotmail.com.