CONCISE REPORTS DiVerentiation between primary and secondary Raynaud’s phenomenon: a prospective study comparing nailfold capillaroscopy using an ophthalmoscope or stereomicroscope

Background—Nailfold capillary microscopy is a routine procedure in the investigation of patients with Raynaud’s phenomenon (RP). As a standard method, nailfold capillary morphology is inspected with a stereomicroscope to look for capillary abnormalities such as giant loops, avascular areas, and bushy capillaries, which have all been found to be associated with certain connective tissue diseases. Aim—To investigate prospectively whether nailfold capillary inspection using an ophthalmoscope is of equivalent diagnostic value to standard nailfold capillary microscopy. Method—All the fingers of 26 patients with RP were examined in a blinded fashion and compared with the final diagnosis one month later. Results—All giant loops, large avascular areas, and bushy capillaries were identified by both methods. The correlation for moderate avascular areas and crossed capillaries was 0.93 and 0.955 respectively. The correlation for minor abnormalities that do not contribute to the diVerentiation between primary and secondary RP was 0.837 and 0.861 respectively. All patients were classified identically by the two methods. Conclusion—For the evaluation of patients with RP, nailfold capillary morphology can reliably be assessed with an ophthalmoscope. (Ann Rheum Dis 2001;60:407–409) Raynaud’s phenomenon (RP) is a common complaint of patients attending angiology or rheumatology clinics. Intermittent acral ischaemia can be related to either a functional dysregulation of the autonomous nervous system (primary RP) or structural changes in the supplying arteries in systemic vasculitis or connective tissue diseases, so called secondary RP. The distinction between primary and secondary RP is critical, because patients with the latter require further medical evaluation and surveillance. As distinct patterns of nailfold capillaries have been described for most connective tissue diseases, nailfold capillary microscopy (NCM) has become an established procedure in the examination of patients with RP. However, NCM requires a bifocal stereomicroscope, a fibre-optic illuminator, and at least some space. A few reports indicate that some major nailfold capillary abnormalities such as giant loops can also be visualised with an ophthalmoscope or a modified dermatoscope. We performed a prospective study to see whether, for the evaluation of patients with RP, diagnostic NCM can be simplified to a bedside (or desk side) procedure by using an ophthalmoscope instead of a stereomicroscope.