A world through rose-colored glasses

 

 

Top: Bob McClenathan trains a boy to use a magnifying glass for reading. Bottom: Red-tinted lenses remove the part of the spectrum most disturbing to those with the disorder.

The Pingelapese call the disorder maskun – “not-see.” People with achromatopsia see in black and white with about 20/200 vision, which by U.S. standards would make them legally blind. Their pupils jerk around, a condition called nystagmus. And, most disabling of all, they are hypersensitive to light – literally blinded by the light. “It’s easy to tell an achromat when you see one,” says Bob McClenathan, an optometrist and member of the Rotary Club of Lancaster, Pa., who has helped patients with the rare genetic disorder during two missions to Pingelap, Micronesia. “They usually are like this” – he squints – “but they’re not trying to squint like a nearsighted person squints. They’re just trying to block out the light.” He compares it to coming out of a dark movie theater. “You know how blinding that is to you? It’s like that for them all the time.”

McClenathan’s involvement with the Pingelapese and achromatopsia was, as he likes to put it, serendipity. A few years back, after he eased into semi-retirement and his last child went off to college, he signed on for a district water project in Brazil. But because of his skills, organizers asked him to participate instead in a concurrent eye mission. He was hooked. He had seen low-income patients, often at little or no cost, at his practice in Lancaster at the Susquehanna Association for the Blind and Vision Impaired, but much of the need he observed during the project was more serious than he’d ever imagined. The fellowship with other Rotarians and the chance for an adventure were big draws too.

After his trip to Brazil, he looked on the Rotary International website, on what is now called ProjectLINK, and searched for another health mission he could participate in. The one in Micronesia needed a low-vision specialist, which he was, and the Rotary Club of Guam Sunrise was involved. McClenathan was born on Guam while his father was in the U.S. Navy. “I’ve just got to go,” he thought. “It’s meant for me.”

The more he learned about Pingelap, which was featured in Oliver Sacks’ 1997 book, The Island of the Colorblind, the more fascinated he became. In 1775 a typhoon decimated the atoll, which is 70 miles from its nearest neighbor and only half as big as New York City’s Central Park. Of its 1,000 inhabitants, only 20 survived. Among the lucky was a prolific king, or nahnmwarki in the local language, who went to work repopulating the island. His many descendents inherited from him a paradise filled with lush greenery, a rainbow of tropical flowers, and a turquoise blue lagoon – and a genetic disorder that makes them unable to see it very well. “It’s a set of circumstances 200-some years ago that has left a legacy of visual disability,” McClenathan says. “It’s an amazing history.”

Achromatopsia is an unusual condition in the rest of the world, afflicting 1 out of every 30,000 people (0.0033 percent). But on Pingelap, 4 to 10 percent of residents are estimated have the disorder, and 30 percent carry the recessive gene for it.

McClenathan and his wife, Kay, went on the mission to Brazil in 2004, and with the support of his own club, the Rotary clubs of Guam Sunrise and Pohnpei, Micronesia, as well as a Matching Grant from The Rotary Foundation, they took their first trip to Micronesia in 2005.

It was a 24-hour journey just from their house to Guam, where the McClenathans stopped to tour the island, speak at a Rotary club meeting, and start seeing patients with Pingelapese ancestry. From there, they took a 4 1/2-hour flight to Pohnpei, Micronesia’s largest island and home to its capital. They helped people on Pohnpei and Mokil, another tiny atoll and Pingelap’s nearest neighbor; both islands have descendents from Pingelap and a high incidence of achromatopsia.

They almost didn’t make it to Pingelap. The government had closed the airstrip on the atoll after it washed away in a storm in 2004. It had been a year and a half since anybody had traveled to or from the island, save for a government inspector nine months earlier to see if the airstrip was ready to reopen. (It wasn’t.) But the McClenathans persisted and finally received special permission to fly in. The Pingelapese were out of rice, so the McClenathans brought 40 pounds of it with them. They spent their time on the atoll wondering whether the sole pilot flying to the island would decide that he didn’t want to attempt another landing, and would abandon them to a life of breadfruit, fish, and taro.

Before their second trip in 2009, the airstrip had been rebuilt and damaged again. Their journey had once again been delayed – this time for a year – when the pilot suspended service because of a dispute with the government. The McClenathans could have taken the ship that services the atoll, but they would have had to wait six months until it came around again to go home.

On Pingelap, they saw patients at the vacant family home of Melner Isaac, a member of the Pohnpei club who traveled with them on one of the trips. The island’s population reached more than 1,000 in the 1970s and ’80s, Isaac says, but the Compact of Free Association, signed in 1982 by Micronesia and the United States, has lured many islanders to job opportunities in Guam, Hawaii, or on the U.S. mainland, and the population has now dropped below 300. As for Isaac, his father was a teacher and his mother the atoll’s only midwife. He moved to Pohnpei, a volcanic island that’s a 170-mile ship ride away, to attend high school and stayed.

Isaac does not have achromatopsia, but he has relatives who do. His best friend has the disorder, and Isaac recalls him being unable to run around outside and spearfish with his friends. “He was disadvantaged in life,” he says.

Before meeting the McClenathans, Isaac had never heard the story of the typhoon behind the island’s high prevalence of achromatopsia, though a lot of folklore surrounds the disease. In one legend, he says, a clever blind boy saves the other children from a giant monster killing the islanders. In another, a Pingelapese man who was supposed to be a missionary is cursed to have blind children when he has an affair with a woman. “Pingelapese do understand this sickness is genetic,” he says. “But frankly no one really cares to know how it came about.”

While McClenathan specializes in low-vision patients, until traveling to Micronesia, he’d never examined somebody with achromatopsia. Between his two trips, he examined 600 to 700 people, 60 to 70 of whom had the disorder. “I think I’ve seen more achromats than anyone in the world,” he says.

For a person with normal vision, light rays hit the retina at the back of the eye, and the photoreceptors, called rods and cones, convert the rays into electrical signals to the brain. Cones, which are concentrated in the center of the retina, work in bright light and handle details and color vision. They’re the photoreceptors you’re using as you read this page. Rods, on the periphery of the retina, are very sensitive and take over in low light; vision from rods is less sharp, dealing with shapes and movement in shades of grey. People with achromatopsia have cones, but they don’t work. All of their vision comes from the rods.

The disorder doesn’t have a cure, so McClenathan had to treat the symptoms. To combat the debilitating effects of bright sunlight, he prescribed glasses with red lenses (or orange or plum, depending on personal preference). Rods respond only to low-intensity levels, especially at the blue end of the spectrum. By allowing only red light to pass through, the tinted lenses remove the part of the spectrum most disturbing to the rods. They act like dark sunglasses.

McClenathan also gave islanders monocular telescopes or magnifying glasses – simple tools that his low-vision patients in Pennsylvania use, though less technologically advanced – if necessary to treat other ocular issues. They selected from frames donated by McClenathan’s vendors, and he brought notes about their prescriptions back with him to the United States, where a laboratory cut and tinted the lenses at no cost. (No such lab exists on the islands McClenathan visited.) He was able to ship the glasses back through the U.S. Postal Service; because of Micronesia’s status as a freely associated state, it uses U.S. ZIP codes, and shipping costs the same as it does domestically.

Back home, McClenathan’s practice is in an old feed mill in downtown Lancaster, a region known for its Amish and Mennonite communities. (Occasionally one of his patients arrives by horse and buggy.) Word spread of his newfound expertise after an article about his first mission ran in the local paper, prompting Marlene Zimmerman to take two of her sons with achromatopsia to see him. The Zimmermans, who are Old Order Mennonite, have discovered other distant relations with the disorder as well, some of whom have also traveled to see McClenathan for help. As with the Pingelapese, inherited disorders proliferate among Mennonite people because they tend to marry within their community.

Zimmerman says that because of their achromatopsia, her sons – Darren, 15, and Justin, 9 – didn’t like to play outside on sunny days. If they did go out, they’d wear a cap and sunglasses. “One time Darren almost walked right over the edge of a retaining wall. He didn’t see it,” she says. After McClenathan gave them dark red sports sunglasses, her sons became much more comfortable outside, and their depth perception improved. Darren now even has red-tinted contact lenses. “We were amazed at our oldest one. He didn’t enjoy volleyball because he couldn’t always see the ball. Once he got the glasses, he could see that volleyball, and now he loves it.”

After the first mission, McClenathan received an RI Service Above Self Award, Rotary’s highest honor for an individual. He has also traveled to Honduras, Kenya, and Peru, but he has always wanted to return to Micronesia. “I felt an affinity for the people and for the Rotarians with whom I have worked and with whom I have shared fellowship,” he says. And then there’s the chance to be a part of an amazing story.

In The Island of the Colorblind, Sacks remembers watching a young boy running confidently in broad daylight, wearing a new sun visor he’d just received from the author and his crew. “I can see, I can see!” he shouted as he pointed to it. The McClenathans never expected to have the same experience. But when they put red-tinted glasses over the squinting eyes of a six-year-old girl who, like Zimmerman’s sons, had spent most of her life avoiding outdoor activities, she immediately opened them. “Now I can go play with my friends!” she said.