Spots before the eyes: a prevalence and clinicoradiological study of senile scleral plaques

Two cases of cartilaginous metaplasia in the sclera of Japanese White rabbits

Spontaneous cartilaginous metaplasia of the sclera has not been reported in rabbits. Herein, we report two cases of spontaneous cartilaginous metaplasia in the sclera of Japanese White (JW) rabbits. Case 1 was noted in a 14-week-old male Kbs:JW rabbit that received a single ocular instillation of 20% isoproterenol (IP) a day before necropsy, and showed no abnormalities in clinical signs, ophthalmological assessments, and necropsy. Case 2 was noted in a 38-week-old male Kbs:JW rabbit that was housed under light-emitting diode (LED) lighting for 26 weeks and showed no effects of LED on clinical signs, ophthalmological assessments, and necropsy. Histological sections of the eyes of both animals were prepared and stained with hematoxylin and eosin (H&E) and Alcian blue, and immunohistochemical staining for vimentin was performed. The H&E-stained specimens showed focal hyaline cartilage-like tissues distributed between the scleral fibers at the posterior pole in both cases. The surrounding scleral fibers were compressed and/or partially destroyed by the cartilage-like tissue. The cartilage-like matrix was stained blue by Alcian blue, and immunohistochemistry showed that chondrocyte-like cells were positive for vimentin. Based on these findings, we diagnosed cartilaginous metaplasia in the sclera of Kbs:JW rabbits. The lesion was farther from the IP administration site in Case 1 and was not accompanied by other ophthalmological or histopathological abnormalities in either of the cases. This implies that the lesions occurred spontaneously owing to the abnormal differentiation of neural crest-derived cells.

Senile scleral plaques imaged with enhanced depth optical coherence tomography

PURPOSE

Senile scleral plaques (SSP) are sharply demarcated greyish areas located just anterior to the insertions of the horizontal rectus muscles and thus are frequently encountered during transscleral intravitreal injections. The aim of this study was to characterize SSP using enhanced depth imaging spectral domain anterior segment optical coherence tomography (OCT) in a cohort of patients attending intravitreal injection clinics.

METHODS

Prospective cross-sectional study of 380 patients attending the clinic for intravitreal injections at the Department of Ophthalmology at the Bern University Hospital. Thirty-two patients with SSP were identified and the anatomical features were assessed using anterior segment OCT.

RESULTS

In our patient cohort, we found a SSP prevalence of 8.2%. Senile scleral plaques were easily identifiable using anterior segment OCT and were found at the insertion sites of the horizontal recti muscles. The mean horizontal diameter was 2.2 mm (±760 μm SD), the mean vertical diameter was 3.3 mm (±144 μm SD), and the average surface area was 5.3 mm(2) (±0.4 mm(2) SD). The mean senile scleral plaque thickness was 0.6 mm (±149 μm SD). The mean distance from the limbus was 2.24 mm for nasally located SSP and 3.22 mm for temporally located SSP.

CONCLUSION

SSP are frequently encountered during intravitreal injections as they are located just anterior to the insertion sites of the horizontal recti muscles. Because the scleral stroma is rarefied and due to calcifications within SSP, these areas should be avoided when performing multiple intravitreal injections as this may result in rupture of the sclera.

Eye disease in older people

Age-related changes affect all structures of the eye, and while age-related changes may influence the quality of vision, it is important to distinguish age-related physiological changes from pathological changes. This is important particularly when identifying pathological changes that may be treatable. The prevalence of visual loss increases substantially after 60 years of age and poor vision is the second most prevalent physical disability in older people. This review describes the normal ageing changes of the eye and outlines common ophthalmic diseases affecting older people. We refer to recent advances in diagnosis and treatment, and relevant current research.

Identification of monoclinic calcium pyrophosphate dihydrate and hydroxyapatite in human sclera using Raman microspectroscopy

Raman microspectroscopy was first used to determine the composition of a calcified plaque located at the pterygium-excision site of a 51-year-old female patient's left nasal sclera after surgery. It was unexpectedly found that the Raman spectrum of the calcified sample at 1149, 1108, 1049, 756, 517, 376 and 352/cm was similar to the Raman spectrum of monoclinic form of calcium pyrophosphate dihydrate (CPPD) crystal, but differed from the Raman spectrum of triclinic form of CPPD. An additional peak at 958/cm was also observed in the Raman spectrum of the calcified plaque, which was identical to the characteristic peak at 958/cm of hydroxyapatite (HA). This is the first study to report the spectral biodiagnosis of both monoclinic CPPD and HA co-deposited in the calcified plaque of a patient with sclera dystrophic calcification using Raman microspectroscopy.

Sonographic features of senile scleral calcification

BACKGROUND AND OBJECTIVE

To describe the sonographic features of senile scleral calcification using ultrasound biomicroscopy.

PATIENTS AND METHODS

Four patients in whom senile scleral calcifications were found incidentally on computed tomography studies underwent ultrasound biomicroscopy examination.

RESULTS

The senile scleral calcification was bilateral in three patients and unilateral in one patient. In all patients, the calcified material created the anterior shadowing typical of calcified lesions. The ultrasound biomicroscopy study localized the senile scleral calcification to the subconjunctival layer, superficially above the sclera, and anterior to the horizontal muscles.

CONCLUSIONS

This is the first description of the ultrasound biomicroscopy features of senile scleral calcification. Ultrasound biomicroscopy may serve as a good tool for the accurate localization of the plaque.