Central corneal thickness in children with congenital cataract and children with surgical aphakia: a case- control study A P C Lupinacci, 1 M L da Silva Jorda ˜o, 1 G Massa, 1 C E L Arieta, 1 V P Costa 1,2 1 Department of Ophthalmology, University of Campinas, Campinas, SP, Brazil; 2 Department of Ophthalmology, University of Sa ˜o Paulo, Sa ˜o Paulo, Brazil Correspondence to: Dr A P C Lupinacci, Department of Ophthalmology, University of Campinas, Campinas, SP, Brazil, R. Mario de Andrade, 201 casa 43, Campo Grande, MS 79032- 260, Brazil; alvaro.lupinacci@gmail.com Accepted 3 November 2008 Published Online First 19 November 2008 ABSTRACT Aim: To measure the central corneal thickness (CCT) of children with congenital cataract and surgical aphakia. Methods: Children with congenital cataract or surgical aphakia were prospectively recruited and divided into four groups: unilateral cataract (group 1, n = 14), bilateral cataract (group 2, n = 17), unilateral aphakia (group 3, n = 32) and bilateral aphakia (group 4, n = 44). An age-, sex-, and race-matched control group of normal individuals was selected. Ultrasonic pachymetry was performed by the same observer. Results: The mean CCT of the control group was not significantly different from the normal (p = 0.747) and cataractous eyes of group 1 (p = 0.252). The mean CCTs of both eyes of group 2 were significantly higher than the control group (p,0.01). The mean CCT of the aphakic eyes in group 3 was significantly higher than the contralateral healthy eyes and control eyes (p,0.001). The mean CCTs of both eyes of group 4 were significantly higher than the control group (p,0.001). The mean CCT was significantly higher in aphakic eyes of groups 3 and 4 than in cataractous eyes of groups 1 and 2 (p,0.001). Conclusions: Aphakic eyes due to congenital cataract show thicker corneas than normal phakic eyes. Aphakic eyes after congenital cataract extraction show thicker corneas than eyes with congenital cataracts, suggesting that the increase in CCT occurs postoperatively. Congenital cataract is an important cause of visual impairment among children. Although cataract extraction is performed at early ages to prevent amblyopia, other complications, such as secondary glaucoma, continue to threaten the visual out- come. 1–4 The reported prevalence of glaucoma after congenital cataract extraction varies from 1% to 32%. 45 With longer follow-up, the prevalence may be as high as 100%. 6 This wide range is due to difficulties in establishing a precise criteria for the diagnosis of glaucoma in children, 7 different surgical techniques, variable follow-up and differ- ent ages at diagnosis and cataract extraction. 5 8–10 Indirect ophthalmoscopy, gonioscopy, compu- terised perimetry and other exams are difficult to perform in children. 7 Thus, intraocular pressure (IOP) has an important role in the evaluation of children with glaucoma or at risk for glaucoma. 7 11 However, applanation tonometry may overesti- mate IOP in patients with increased central corneal thickness (CCT). 12–14 Some authors have reported increased CCTs among children who underwent cataract extraction, 15–19 which may influence the diagnosis and management of glaucoma. Nevertheless, it is unclear whether the increased CCT is present before cataract surgery or develops postoperatively. In this study, we investigated the CCT and IOP measurements of eyes with congenital cataract and aphakic eyes after congenital cataract extraction. PATIENTS AND METHODS Thirty-one individuals with congenital cataract and 76 aphakic subjects due to congenital cataract were prospectively included in this cross-sectional case-control study. All subjects are followed at the Congenital Cataract Service of the University of Campinas, Brazil. Age-, gender- and race-matched unrelated controls were obtained among healthy individuals followed at the Pediatric Ophthalmology Service of the University of Campinas or their companions. Written informed consent was obtained from all participants or a legally responsible person, after approval by the Institutional Ethics Committee (number 248/2006 CAAE 0181.0.146.000-06) and registration at the Australian New Zealand Clinical Trial Register (http://www.anzctr.org.au, registration number ACTRN012606000365561). The study protocol has followed the tenets of the Declaration of Helsinki. Included subjects were divided into four groups: unilateral congenital cataract (group 1), bilateral congenital cataract (group 2), unilateral aphakia (group 3) and bilateral aphakia (group 4). All groups had age-, gender- and race-matched healthy controls without any previous history of ocular surgery or laser, ocular trauma or glaucoma. None of the included subjects was using any topical or systemic medication that could interfere with IOP or CCT measurements. Inclusion criteria were: group 1—unilateral congenital cataract, with a healthy contralateral eye; group 2—bilateral congenital cataract; group 3—unilateral aphakia due to congenital cataract extraction, with a healthy contralateral eye; and group 4—bilateral aphakia due to congenital cataract extraction. Subjects with signs of devel- opmental glaucoma (ie, buphthalmos, increased corneal diameter, Haabs striae, etc.), with a previous history of ocular trauma, intraocular laser or surgery other than cataract extraction, persis- tent hyperplastic primary vitreous, aniridia, clini- cally detectable corneal oedema, glaucoma or any systemic disease that influences CCT (eg, Down Syndrome, Marfan Syndrome, sphingolipidosis) were excluded. Glaucoma was defined when two or more of the following optic disc alterations were Clinical science Br J Ophthalmol 2009;93:337–341. doi:10.1136/bjo.2008.137596 337