A TECHNICAL IMPROVEMENT OF THE HAAG‐STREIT PACHOMETER Short Communication

In order to assess a possible damage to the corneal endothelium during pressure induced abnormal hydration of the cornea, 23 patients with a previous attack of unilateral acute glaucoma were photographed with a specular microscope. As compared to the healthy side, the endothelium of the affected side showed a mean decrease in cell density of 23.1%, range --4.8 to 68% (P less than 0.001). In retrospect this cell loss was found to correlate significantly to the increase in corneal thickness measured during the acute attack on first day of admission. At present examination mean central corneal thickness was identical in the affected and unaffected eye. A large variation was, however, found in the intraocular pressure of the previously attacked eye. If the subject inter-eye difference in intraocular pressure was related to the inter-eye difference in corneal thickness is significant negative correlation appeared. It is concluded that the intraocular pressure has a dual effect on the corneal hydration: if the endothelium is intact, the intraocular pressure decreases corneal thickness, whereas an increase is seen only if the endothelium is acutely damaged.

Section: Methodsmentioning

confidence: 99%

The Endothelial Cell Damage in Acute Glaucoma. On the Corneal Thickness Response to Intraocular Pressure

Olsen

1980

“…The central corneal thickness was measured the day before and on each of four days after surgery using a modified Haag-Streit pachometer (Ehlers & Sperling 1977). All measurements were single determinations taken as the closest 5 I".…”

Section: Methodsmentioning

confidence: 99%

Corneal Thickness and Endothelial Damage After Intracapsular Cataract Extraction

Olsen

1980

In a prospective study corneal thickness and specular microscopic findings of corneal endothelium are reported in 37 patients undergoing intracapsular cataract extraction. Central endothelial cell loss was estimated six months after the operation and was found to correlate significantly to the immediate post-operative increase in central corneal thickness. A subgroup of patients showing slight endothelial dystrophy prior to the operation showed a significantly higher increase in corneal thickness fourth day after the operation. Six months after the operation a significant residual increase in corneal thickness was found for this group, while the rest of the patients had returned to near pre-operative levels. No correlation was found between cell loss and residual corneal thickness increase at this time. Six months after the operation a vertical difference in cell density was found. This difference could be correlated to the age of the patient, presumably indicating a less complete redistribution of the cell population in older patients.

“…Central corneal thickness was determined by the Haag-Streit pachometer, modified as previously reported (Ehlers 1974;Ehlers & Sperling 1977). When a perpendicular incidence of the light beam is optically secured, identical values are found in right and left eyes, and the previously used reference value of 0.520 mm in right eye and 0.524 in the left had to be altered.…”

mentioning

confidence: 99%

Central Thickness in Corneal Disorders

Ehlers

Bramsen

1978

Self Cite

In the single individual the central corneal thickness (CCT) shows only small variations. Therefore CCT has been studied in a number of corneal diseases in order to investigate if this dimension might contribute to the diagnosis or to the understanding of the pathogenesis. Normal CCT was found in hereditary dystrophies with the exception of the macular dystrophy of Groenouw (type II), which showed a significantly reduced thickness. Reduced CCT was found in chronic degenerations of leutic, tuberculous or indefinite nature. Marginal degenerations of Fuchs-Terrien type also showed reduced CCT. The possible role of abiotrophic processes in this corneal thinning is dicussed. Endothelial dysfunction is indicated by increased CCT. This occurs in bullous keratopathy and in many acute disorders. Vascularisation of the cornea does not preclude the occurrence of normal or even reduced thickness.