ABSTRACT
Background: keratoconus is bilateral [usually asymmetrical], progressive, non inflammatory, cone like anterior protrusion of the cornea involving the central and the inferior para central areas that results in corneal ectasia, astigmatism and diminution of vision. It usually seen after puberty, with incidence of 1 in 2000 of general population, the major benefit of corneal tomography is the measurement of the posterior corneal surface, because the posterior surface contributes minimally to the overall refractive power of the eye [due to the minimal difference between the index of refraction of the cornea and aqueous] it was considered less important both diagnostically and therapeutically. The posterior cornea, however, is an earlier indicator of ectatic change or ectasia susceptibility
Aim of the Work: to determine the changes of posterior corneal astigmatism in cases with keratoconus
Patients and Methods: one hundred eyes of 50 patients were included in this retrospective, case control study which adhered to the tenets of the Declaration of Helsinki and was approved by the Ethics Committees of the Ain Shams University Hospitals. All patients included in the study provided informed consent, these cases were divided into: 1- Keratoconus group: comprised 50 eyes of 25 patients with keratoconus diagnosed on the basis of clinical and topographic signs and 2- Control group comprised 50 eyes of 25 normal candidates for refractive surgery
Results: the mean magnitudes posterior corneal astigmatism[PCA] were approximately 1 D, and The PCA values were significantly associated with the severity ofKeratoconus[KC], the posterior corneal surface was more affected in the early stages of KC
Conclusion: we found that the mean magnitudes PCA were approximately 1 D, and The PCA values were significantly associated with the severity of KC, the posterior corneal surface was more affected in the early stages of KC
ABSTRACT
Background: Myopic traction maculopathy [MTM], also known as myopic foveoschisis typically occurs in highly myopic eyes often leads to blindness. The pathologic features of foveoschisis may be alone or it may be associated with foveal detachment or macular hole
Aim of the work: To assess the role of vitrectomy with internal limiting membrane [ILM] peeling in changing visual outcomes and optical coherence tomography [OCT] findings of the macula in patients with myopic vitreo-macular traction syndrome
Design of the study: prospective Interventional case series
Methodology: 19 high myopic eyes of 17 patients divided into 3 groups: Group 1 [Foveoschisis only]: [6 eyes]. Group 2 [foveoschisis and foveal detachment]: [6 eyes]. Group 3 [foveoschisis, foveal detachment and macular hole]: [7 eyes]
Results: In our study, the visual acuity significantly improved in all eyes at 6 months postoperatively. This was associated with significant reduction of central foveal thickness. There was statistically significant inverse correlation between changes in best corrected visual acuity [BCVA] and both basal refraction and basal BCVA. There was statistically significant direct correlation between changes in central foveal thickness [CFT] and basal refraction. On the other hand, there was significant inverse correlation between changes in CFT and basal CFT
Conclusion: Visual improvement was better in foveoschisis with foveal detachment eyes than in foveoschisis or macular hole eyes