A C T A O P H T H A L M O L O G I C A

60 (1982) 945-948

Department of Ophthalmology (Head: N . Ehlers), A r h u Kommunehospital, University of Aarhus, Arhus, Denmark

CENTRAL CORNEAL THICKNESS IN PATIENTS WITH RETINAL DETACHMENT

JENS WINTHER

Central corneal thickness was measured in 20 patients with retinal detachment and in an age-matched control group. Central corneal thickness was signifi- cantly lower in the detachment eye and the contralateral eye. I t is hypotheti- cally suggested that the thin central cornea and the retinal detachment are ocular manifestations on a generalized connective tissue defect.

Key word$: central cornea thickness - retinal detachment - connective tissue.

In the literature only one study has been done on central cornea thickness (CCT) in retinal detachment (Kruse-Hansen et al. 1971). In this study CCT in eyes with retinal detachment and in the contralteral eye was lower than normal.

A number of investigators, cited by Mishima (1982), have found no sex or age dependent changes in CCT, but in one study a corneal thinning with age, predominantly in males, in a great Greenland Eskimo population, has been reported (Alsbirk 1978).

Retinal detachment mostly occurs in old age and the purpose of this study has been to measure the CCT wiht the modified Haag-Streit pachometer (Mishima 1968; Ehlers & Sperling 1977) in patients with idiopatic retinal detachment compared with an age-matched control group.

Received on May 26th. 1982.

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Winther CCT in retinal detachment

Material and Methods

The material consists of 20 consecutive patients with unilateral idiopatic retinal detachment admitted for surgery. Patients with diabetes, glaucoma, aphakia, excessive myopia (> -6D) and retinal detachment caused by intraocular tumour or trauma were not included.

There were 12 females and 8 males. The average age was 63.8 years ranging from 24 to 79 years.

For each patient with idiopatic retinal detachment a healthy patient f 5 years with light fixation on both eyes admitted to the department for cataract, strabismus or stenosis of nasolacrimal duct were selected as member of the control group.

All measurements were performed by the author. Triple determinations taken as the nearest 0.005 mm reading on the pachometer scale were used and the mean value was used in the calculations between the eyes with retinal detachment and the contralateral eyes. The mean value of the CCT in both eyes were used in the calculations between patients with idiopatic retinal detachment and the control group.

The coefficient of variation of the CCT measurement is for a trained examinator about 1 % (Olsen et al. 1980).

Eyes with retinal detachment which could not fixate light were excluded and only the CCT determination in the contralateral eyes in those patients were included in the study.

Resu I ts

Sixteen eyes with idiopatic retinal detachment were measured. 4 eyes could not fixate light. The average CCT was 0.494 f 0.006 (mm f SEM).

Twenty contralateral eyes were measured. The average CCT was 0.498 f 0.006 (mm f SEM). The difference between the 2 values is not significant by pairwise comparison for the 16 patients (t = 1.27,O. 10 P C 0.20).

The average mean value of the CCT in both eyes in patients with idiopatic retinal detachment was 0.496 k 0.006 (mm f SEM). The average mean value of the CCT in both eyes in the age-matched control group was 0.526 f 0.004 (mm k SEM). This is a significant difference (t = 4.3, P < 0.001).

Table 1 . CCT in patients with retinal detachment and in the control group.

Patients with unilateral retinal detachment

Patients in the control group

both eyes (N = 40)

(N = 16) (N = 20)

CCT+SEM mm 0.494 f 0.006 0.498 f 0.006 0.526 0.004

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Winther CCT in retinal detachment

Discussion

The results in this study support the results from Kruse-Hansen et al. (197 1). In 40 patients with retinal detachment they found in detachment eyes and contralateral eyes that CCT for the right eyes was 0.491 f 0.004 (mm k SEM) and for the left eyes was 0.508 k 0.005 (mm k SEM). CCT in left eyes were greater than CCT in right eyes because of the systematic methodological error increasing with angle kappa (Ehlers & Kruse-Hansen 197 1). Withe the modified Haag-Streit pachometer used in this study this error was eliminated.

The pathogenetic factors for the development of retinal detachment are chorioretinal and vitreous degenerations (Andersen & Edmund 1966). The high incidence of retinal detachment in the second eye and families with hereditary retinal detachment suggests that the eyes of some persons are disposed to retinal detachment. CCT has been found independent of ocular parameters such as visual acuity, refraction, corneal astigmatism, depth of anterior chamber, lens thickness, lenght of vitreous body, axial length of the eyeball, optic disc and retinal abnormalities and red-green colour vision (Ehlers et al. 1975; Ehlers & Kruse- Hansen 1976). In disorders such as osteogenesis imperfecta and Ehlers-Danlos syndrome, CCT is lower than normal (Bramsen et al. 1980; Moestrup 1969).

Kruse-Hansen et al. (197 1 ) found smaller thickness of epidermis and dermis and degenerative changes in collagenous and elastic fibers in full skin biopsies from the femur in 17 patients with retinal detachment.

This suggests hypothetically that not only are the eyes disposed to retinal detachment, but that the lower CCT and the retinal detachment are manifestations of a generalized defect in connective tissue.

References

Alsbirk P H (1978): Corneal thickness. I . Age variation, sex difference and oculometric

Andersen S Ry & Edmund J 81966): Pathology in retinal detachment. Acta Ophthalmol

Bramsen T, Pedersen U & Corydon L (1980): Central corneal thickness in osteogenesis

Ehlers N & Kruse-Hansen F (197 1): On the optical measurement of corneal thickness. Acta

Ehlers N, Kruse-Hansen F & Aasved H (1975): Biometric correlations of corneal thickness.

Ehlers N & Kruse-Hansen F ( 1976): Further data on biometric correlations of central corneal

correlations. Acta Ophthalmol (Copenh) 56: 95- 101.

(Copenh). Suppl84: 25-44.

imperfecta. Ugeskr Laeg 142: 1609- 1610.

Ophthalmol (Copenh) 49: 65-81.

Acta Ophthalmol (Copenh) 53: 652-659.

thickness. Acta Ophthalmol (Copenh) 54: 774-778.

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Winther CCT in retinal detachment

Ehlers N & Sperling S (1977): A technical improvement of the Haag-streit pachometer. Acta Ophthalmol (Copenh) 55: 975-984.

Kruse-Hansen F, Ehlers N, Bentzen 0 & Segaard H (1971): Central corneal thickness in retinal detachment. Acta Ophthalmol (Copenh) 49: 467-472.

Mishima S (1968): Corneal thickness. SurvOphthalmol 13: 57-96. Mishima S (1982): Clinical investigations on the corneal endothelium. Am J Ophthalmol

Moestrup B (1969): Tenuity of cornea with Ehlers-Danlos syndrome. Acta Ophthalmol 93: 9.

(Copenh) 47: 704-708.

Author’s address:

Jens Winther, Eye Department, Arhus Kommunehospital, DK-8000 Arhus C, Denmark.

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