The effect of pterygium surgery on contrast sensitivity and corneal topographic changes

Joo Youn Oh, Won Ryang WeeDepartment of Ophthalmology, Seoul National University Hospital, Seoul, KoreaPurpose: To investigate the effect of pterygium surgery on corneal topography and contrast sensitivity.Patient and methods: The IRB approved this prospective, nonrandomized, self-controlled study. Computerized videokeratography (Orbscan II) was performed in 36 patients with primary pterygia, both before and 1 month after pterygium excision with limbal-conjunctival autografting. The topographic parameters were compared. Spatial contrast sensitivity testing was performed using VCTS 6500. Differences between preoperative and postoperative values were evaluated statistically.Results: The mean Sim K astigmatism and irregularity index, significantly decreased after pterygium surgery. The mean refractive power significantly increased after the operation. The “with-the-rule” astigmatism induced by pterygium became “against-the-rule” astigmatism after pterygium removal (P = 0.041). The contrast sensitivity of 6, 12, and 18 cycles per degree, significantly increased from 1.55 ± 0.28, 0.97 ± 0.47, and 0.29 ± 0.16 to 1.72 ± 0.18, 1.21 ± 0.44, and 0.65 ± 0.48, respectively (P = 0.007, <0.001, <0.001, respectively).Conclusions: Pterygium surgery significantly reduces corneal topographic astigmatism and improves contrast sensitivity.Keywords: corneal topography, visual acuit

Spontaneous corneal melting during pregnancy: a case report

This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.Abstract Introduction Biomechanical changes in the cornea during pregnancy might lead to pathological conditions such as corneal perforation or melting. Case presentation A 33-year-old Asian female who underwent penetrating keratoplasty in both eyes developed corneal melting in the right eye and marginal keratitis in the left eye in her fifth month of pregnancy. Marginal keratitis in the left eye immediately subsided with topical steroid therapy. However, spontaneous corneal melting progressed in the right eye, despite oral steroid therapy and amniotic membrane transplantation. We performed tectonic penetrating keratoplasty and corneoscleral grafting in the right eye. Conclusion We advise caution in the ophthalmologic care of pregnant patients who have preexisting corneal thinning disorders or who have undergone multiple corneal surgeries, because physiologic changes during pregnancy might contribute to corneal changes leading to spontaneous melting especially in patients with compromised cornea

Estimation of axial curvature of anterior sclera: correlation between axial length and anterior scleral curvature as affected by angle kappa

Background: Though the development and fitting of scleral contact lenses are expanding steadily, there is no simple method to provide scleral metrics for scleral contact lens fitting yet. The aim of this study was to establish formulae for estimation of the axial radius of curvature (ARC) of the anterior sclera using ocular biometric parameters that can be easily obtained with conventional devices. Methods: A semi-automated stitching method and a computational analysis tool for calculating ARC were developed by using the ImageJ and MATLAB software. The ARC of all the ocular surface points were analyzed from the composite horizontal cross-sectional images of the right eyes of 24 volunteers; these measurements were obtained using anterior segment optical coherence tomography for a previous study (AS-OCT; Visante). Ocular biometric parameters were obtained from the same volunteers with slit-scanning topography and partial coherence interferometry. Correlation analysis was performed between the ARC at 8 mm to the axis line (ARC[8]) and other ocular parameters (including age). With ARC obtained on several nasal and temporal points (7.0, 7.5, 8.0, 8.5, and 9.0 mm from the axis line), univariate and multivariate linear regression analyses were performed to develop a model for estimating ARC with the help of ocular biometric parameters. Results: Axial length, spherical equivalent, and angle kappa showed correlations with temporal ARC[8] (tARC[8]; Pearson’s r = 0.653, −0.579, and −0.341; P = 0.001, 0.015, and 0.015, respectively). White-to-white corneal diameter (WTW) and anterior chamber depth (ACD) showed correlation with nasal ARC[8] (nARC[8]; Pearson’s r = −0.492 and −0.461; P = 0.015 and 0.023, respectively). The formulae for estimating scleral curvatures (tARC, nARC, and average ARC) were developed as a function of axial length, ACD, WTW, and distance from the axis line, with good determinant power (72 − 80 %; SPSS ver. 22.0). Angle kappa showed strong correlation with axial length (Pearson’s r = −0.813, P <0.001), and the different correlation patterns of nasal and temporal ARC with axial length can be explained by the ocular surface deviation represented by angle kappa. Conclusions: Axial length, ACD, and WTW are useful parameters for estimating the ARC of the anterior sclera, which is important for the haptic design of scleral contact lenses. Angle kappa affects the discrepancies between the nasal and temporal scleral curvature.Korea (South). Ministry of Health & Welfare (Projects A084496 and A120018

Conjunctival sarcoidosis presenting as limbal conjunctival hypertrophy: a case report

Introduction : To the best of our knowledge, this is the first report of a case of conjunctival sarcoidosis that presented as limbal conjunctival hypertrophy and was controlled with topical cyclosporine. Case presentation : A 70-year-old Asian woman presented with painless limbal conjunctival hypertrophy. An incisional biopsy of the hypertrophic lesion showed noncaseating granulomas that consisted of multinucleated giant cells and epithelioid cells. The results of a systemic evaluation were normal except for a slight increase in serum angiotensin-converting enzyme to 58.9IU/L (normal range, 8 to 55IU/L). Twice-daily 0.05% topical cyclosporine was prescribed for the treatment of remaining lesions. After two months, the lesions had completely resolved and her serum angiotensin-converting enzyme level had normalized. Conclusions : Sarcoidosis should be considered in the differential diagnosis of conjunctival hypertrophy. Topical cyclosporine can be useful in conjunctival sarcoidosis.Peer Reviewe

Corneal keloid: four case reports of clinicopathological features and surgical outcome

This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.Abstract Background Surgical outcome of corneal keloid is largely variable depending on reports, although surgical management is inevitable in visually significant cases. We here report clinical features, histopathological findings, and surgical outcome of four cases of corneal keloid. Case presentation Four Korean male patients without a history of corneal trauma or disease were clinically and histologically evaluated for a slowly-growing, white opacity in the cornea. On slit lamp examination, corneal lesions appeared as a solitary, pearly white, well-circumscribed nodule with a smooth and glistening surface. Because the lesions involved the visual axis deteriorating the visual acuity, the nodules were surgically removed by superficial keratectomy in all patients. Amniotic membrane transplantation was combined in three patients, and an intraoperative mitomycin C application in two patients. Hematoxylin-eosin staining of the excised nodules revealed epithelial hyperplasia, Bowmans layer disruption, thick and irregularly-arranged collagen fibers in the stroma, and accumulation of prominent fibroblasts, which are consistent with the diagnosis of corneal keloid. The corneal keloids recurred in all patients within 10 months of surgical excision and outgrew the boundary of the excised area. Conclusion A diagnosis of corneal keloid should be suspected in patients presenting with an enlarging, white, glistening corneal nodule, even in the absence of a history of corneal trauma or disease. The recurrence is common after surgical excision, and the lesion can be exacerbated by surgery