A case of proliferative diabetic retinopathy in which scintillating particles appeared in the intravitreal cavity after laser photocoagulation

Abstract

Background: To report a case of proliferative diabetic retinopathy (PDR) exhibiting the appearance of scintillating particles presumed to be crystallin inside the intravitreal cavity after laser photocoagulation.

Case presentation: A 56-year-old male patient presented at our outpatient clinic after becoming aware of decreased vision in his right eye. Ocular examination performed at the patient's initial visit revealed a massive preretinal macular hemorrhage due to PDR in his right eye. Fundus fluorescein angiography revealed extensive retinal non-perfusion areas and neovascularization in both eyes. However, no opacity was observed in the intravitreal cavity of his left eye. Vitreous surgery was performed on the patient's right eye after ultrasonic phacoemulsification aspiration and intraocular lens implantation. Post surgery, the corrected VA in that eye improved from 0.1 to 1.0. In correlation with the treatment performed on the patient's right eye, we began panretinal photocoagulation on his left eye. Examination performed prior to the patient's third session of panretinal photocoagulation revealed a large number of scintillating particles in the posterior vitreous gel in front of the retina. Examination via slit-lamp microscopy revealed that the particles were of varied hues, and closely resembled a 'Christmas tree' cataract. No posterior vitreous detachment was observed, and since these particles were situated as if captured in the posterior vitreous gel, no eye-movement-associated mobility of the particles was observed. Since the cloudiness was not severe enough to interfere with photocoagulation, additional photocoagulation was performed, and the patient is currently under observation. Six months have now passed since the fourth photocoagulation procedure was performed, and there has been no change in the state of the particles. Optical coherence tomography imaging revealed no change before and after the panretinal photocoagulation. The corrected VA in his left eye has remained at 1.0 during the postoperative follow-up period.

Conclusions: We speculate that the production of crystallin in the retina in this case was triggered by the photocoagulation procedure performed for diabetic retinopathy.

Keywords: Crystallin; Laser photocoagulation; Posterior vitreous gel; Proliferative diabetic retinopathy; Scintillating particl.

Fig. 1

Fundus images obtained at the initial examination of the patient. A massive preretinal macular hemorrhage was observed in the patient’s right eye (a), yet no opacity was observed in the intravitreal cavity of the patient’s left eye (b)

Fig. 2

Fundus images obtained at the third photocoagulation procedure. The premacular hemorrhage was removed in the right eye, and the corrected visual acuity improved from 0.1 to 1.0 (a). In the left eye, a large number of scintillating particles were observed in the posterior vitreous gel in front of the retina b

Fig. 3

Slit-lamp microscopy image obtained at the third photocoagulation procedure. Numerous particles of various colors (i.e., yellow, red, and green) were observed (a). No posterior vitreous detachment had occurred, and the particles were captured in the posterior vitreous gel (b)

Fig. 4

Optical coherence tomography (OCT) imaging obtained before and after the panretinal photocoagulation. The OCT imaging revealed no change before (a) and after (b) the panretinal photocoagulation