Clinical biomicroscopy and retinoscopy findings of keratoconus in a Middle Eastern population

Abstract

Background: The present work was conducted to investigate the prevalence of clinical biomicroscopy and retinoscopy findings of corneas with keratoconus (KC) at first presentation and their relationship with disease severity. Method: In a prospective cross-sectional study, 371 consecutive KC patients were examined by slitlamp biomicroscopy and retinoscopy at the time of diagnosis. This research evaluates the prevalence of clinical findings such as a corneal protrusion, Vogt's striae, Fleischer's ring, Munson's sign, Rizzuti's sign, corneal scars, as well as any additional KC signs such as prominent nerve fibres, scissoring reflex and Charleaux 'oil droplet' sign on retinoscopy. Keratometry (mean K), central and thinnest corneal thickness (CCT and TCT), anterior and posterior elevation (AE and PE), and astigmatism by means of Pentacam, and visual acuity (VA) were recorded for each patient. The severity of KC was graded on the basis of the Keratoconus Severity Score. Results: Corneal protrusion, scissoring reflex, corneal thinning, Fleischer's ring, and prominent nerve fibres were the most prevalent findings in the keratoconic corneas (71.7 per cent, 64.2 per cent, 56.6 per cent, 55.5 per cent and 54.7 per cent, respectively). Those KC patients with these clinical findings had significantly higher mean K, AE and PE, while having significantly lower CCT, TCT and VA compared to those who did not present these signs (p < 0.05). The presence of clinical findings was associated with more severe disease (p < 0.001, all comparisons). Wearing contact lenses was associated with the increase in the risk of corneal scarring (p = 0.009, odds ratio = 1.761, 95 per cent confidence interval = 1.126 to 2.755). Conclusion: This study provided information regarding the presence of the clinical slitlamp biomicroscopic and retinoscopic findings with severity of KC. A positive association was found between the presence of clinical signs and topographic parameters. In addition, wearing contact lenses was associated with the increase in the risk of corneal scarring.

Keratoconus: An updated review

“…This slit lamp finding also corresponds with stromal haze and hyperreflectivity as observed using confocal microscopy [67]. In severe cases, highly pronounced cones can create a V-shaped deformation of the lower eyelid during downgaze, known as Munson's sign [141,147]. Rizzuti's sign, a bright reflection of the nasal area of the limbus when light is directed to the temporal limbal area, is another sign frequently observed in advanced stages [148].…”

“…The 'scissor reflex' is observed during retinoscopy assessment. Charlouex's oil droplet reflex is also commonly seen in early keratoconus using retroillumination with a dilated pupil, which produces a dark, round shadow in the corneal midperiphery [141]. Fleischer's ring and Vogt's striae can be observed as the disease severity increases (Table 3).…”

“…Corneal protrusion, the scissors reflex, corneal thinning, Fleischer's ring, and prominent corneal nerve fibres are the most prevalent clinical signs in keratoconus (Fig. 4), with all signs observed in over 50% of patients with keratoconus [141]. However, the time course of the development of these clinical signs and their association with disease severity are highly variable.…”

Comparison of Topographic and Biomicroscopic Features Among Symptomatic Keratoconic Eyes

“…1,5 Naderan et al reported that corneal protrusion, scissoring reflex, corneal thinning, Fleischer's ring, and prominent nerve fibres were the most prevalent findings in the keratoconic corneas (71.7%, 64.2%, 56.6%, 55.5% and 54.7%, respectively). 15 Agrawal et al reported that even though disease severity has a positive relation with anterior segment findings, KC can be diagnosed without AS findings (7%). 4 81% cases had Fleischer ring and Vogt's striae and corneal scarring were more prevalent in severe disease in the study by Agrawal et al 4 CLEK and DUSKS studies reported absence of AS findings in 14% and 15%, respectively.…”

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“…Sometimes it marked progresion during childhood and puberty that may lead to severe visual loss [3]. Retinal reflection scattering is the earliest findings of keratoconus and corneal reflection on the nasal cornea when a penlight is shone from the temporal side as Rizutti's sign is other early findings [4]. Ocular allergy and itching are play a role in keratoconus etiology [5].…”