Another study has come along to support the iPhone as a reliable tool for remotely reviewing medical images and assessing patients when a standard workstation is not available. This time, the Apple smartphone is proving its mettle in ophthalmology.

In an article appearing in the July issue of the Archives of Ophthalmology, researchers from Emory University in Atlanta studied images from 350 patients with headache, focal neurologic deficit, visual changes or high diastolic blood pressure and were surprised to find neurophthalmologists generally rated images to be better on the iPhone 3 than on a desktop PC.

"We expected equal- or lower-quality ratings for photographs displayed on the iPhone compared with the desktop computer, but instead we found that reviewers assigned higher ratings on average for photographs displayed on the iPhone," wrote the researchers, who represent the ophthalmology, neurology, emergency and neurological surgery departments at Emory. "[W]e believe this occurred because the advantages of the iPhone's display (e.g., higher dot pitch and brightness) outweighed its disadvantages (e.g., lower resolution and smaller screen area)."

The researchers noted that the popularity of smartphones "provides a unique opportunity for telemedicine," and see applications in emergency departments, which do not usually have photographic services and high-resolution ophthalmic devices. But while smartphone images have been studied extensively in radiology and dermatology, there is not much existing literature related to smartphone viewing of clinical photographs in eye care.

They also said that the iPhone has limited usefulness in ophthalmologic diagnosis. "We are not suggesting using the iPhone to screen for subtle conditions (e.g., diabetic retinopathy) or as a replacement for in-person ophthalmologic consultation. Rather, we believe the iPhone, and similar devices, in combination with nonmydriatic photography can complement ophthalmologic consultations in settings such as the emergency departmentby allowing for rapid and remote identification of obvious conditions affecting the posterior pole such as papilledema and malignant hypertension," the Emory researchers wrote.

This study did have some other limitations, too. The researchers worked with JPEG images even on the desktop PC screen. JPEG is considered a "lossy," compressed format, with lower resolution than might be found on diagnostic-quality equipment.

Also, the iPhone 3G, released in July 2008, has a resolution of 320 by 480 pixels and a screen density of 165 pixels per inch. Expect better results on newer iPhones with higher-resolution images, particularly the current iPhone 4S with "Retina" display, featuring 960-by-640-pixel resolution at 326 ppi. An LCD computer monitor typically has a density of 100 ppi or less.