Hadiya Farhath, B. Optometry

Research Optometrist, Sankara Nethralaya, India


Flares and the cells (reflection of light from proteins and leucocytes in the aqueous humour)(1) are the major signs in uveitis. Aqueous flare (appears like smoke) intensity indicates the protein concentration formed followed by disruption of blood-aqueous barrier. Aqueous cells (appears like dust in a beam of light) indicates inflammation is at active state. Early successful treatment of flares can prevent ocular complications. Slit-lamp biomicroscope helps us to assess the flares based on the sun grade system, which is considered as a traditional technique(2).  Sun grading is susceptible to intra and inter-observer variability(3). There is a need to develop and introduce a quantitative measure of flares. Laser flare photometry (LFP) measures the light scattered by proteins (flares), and it is expressed in photons/millisecond (ph/ms).

Figure 1 (sun grade vs. duration of treatment) showing variations in the number of flares recorded based on SUN grade system using slit lamp biomicroscope over the 8 visits.

This case, reports the flare values measured using a recently launched version of commercially available LFP. A 27-year-old male referred to the uvea clinic was diagnosed to have non-granulomatous anterior uveitis. The Flare was recorded using both slit-lamp biomicroscope as well as laser flare photometry. An ophthalmologist and an optometrist measured the flare using a slit lamp and LFP respectively in a masked manner. Graphs were plotted based on “sun grade versus duration of treatment” (figure 1) and “Ph/ms versus duration of treatment” (figure 2).

Figure 2 (Ph/ms vs. duration of treatment): showing variations in the number of flares recorded based on LFP over the 8 visits.

 In the first visit, as shown in figure 1, the patient was graded as 0 flares in the left eye and 1+ flare in the right eye based on the sun grade classification. Laser flare photometry (LFP) was used to assess the flare quantitatively which showed 3.7+0.4 ph/ms and 52.9+2.8 ph/ms in the right and left eye respectively (figure 2). He was on medication of predforte 1% for 12times/day, Homatropine 3times/day in the left eye alone (as shown in figures1 and 2). He was also on oral medication of wysolone 20mg 1time/day and Folvite 5mg once in a week. Until 3 visits, there was no significant change in the flare values in both the eyes based on slit lamp biomicroscope and LFP which shows a correlation of LFP with the sun grade. In the fourth and fifth visits, the patient had poor compliance with the medication regimen, which gave rise to an obvious increase in the flare values in the left eye. Both LFP and sun grading values were congruent with each other (LFP: 152.1+5.8 ph/ms, sun grade: 3+). Till this visit, the right eye has no inflammatory reactions and the values were within normal limits. In the 6th visit, the right eye flare value amplified enormously to 252.6+7.3 ph/ms and the sun grade also hiked up to 3+.

Considering the flare values of the left eye’s 5th and 6th visits, the sun grade showed 3+ in both the visits but the LFP (reduced from 152.1+5.8 to 92) was more precise in picking up even a small drop in the flare values. In this case, even this subtle change is crucial because this is the positive sign towards a good prognosis, which helps the clinician to decide on the drug regimen as well as tapering dosage. In sun grade system interpretation is made purely based on the appearance of the anterior chamber and has more interobserver variability(4) and from this case; it is clear that LFP values have an acceptable agreement with the sun grading system, with an advantage of precise flare value.



  1. Holland, G. N. (2007). A reconsideration of anterior chamber flare and its clinical relevance for children with chronic anterior uveitis (an American Ophthalmological Society thesis). Transactions of the American Ophthalmological Society, 105, 344.
  2. Tugal-Tutkun, I., & Herbort, C. P. (2010). Laser flare photometry: a noninvasive, objective, and quantitative method to measure intraocular inflammation. International ophthalmology, 30(5), 453-464.
  3. Konstantopoulou, K., Del’Omo, R., Morley, A. M., Karagiannis, D., Bunce, C., & Pavesio, C. (2015). A comparative study between clinical grading of anterior chamber flare and flare reading using the Kowa laser flare meter. International ophthalmology, 35(5), 629-633.
  4. Ikeji, F., Pavesio, C., Bunce, C., & White, E. (2010). Quantitative assessment of the effects of pupillary dilation on aqueous flare in eyes with chronic anterior uveitis using laser flare photometry. International ophthalmology, 30(5), 491-494.