Detecting the Progression of Normal Tension Glaucoma: A Comparison of Perimetry, Optic Coherence Tomography, and Heidelberg Retinal Tomography

PURPOSE: We compared the abilities of Stratus optical coherence tomography (OCT), Heidelberg retinal tomography (HRT) and standard automated perimetry (SAP) to detect the progression of normal tension glaucoma (NTG) in patients whose eyes displayed localized retinal nerve fiber layer (RNFL) defect enlargements. METHODS: One hundred four NTG patients were selected who met the selection criteria: a localized RNFL defect visible on red-free fundus photography, a minimum of five years of follow-up, and a minimum of five reliable SAP, Stratus OCT and HRT tests. Tests which detected progression at any visit during the 5-year follow-up were identified, and patients were further classified according to the state of the glaucoma using the mean deviation (MD) of SAP. For each test, the overall rates of change were calculated for parameters that differed significantly between patients with and without NTG progression. RESULTS: Forty-seven (45%) out of 104 eyes displayed progression that could be detected by red-free fundus photography. Progression was detected in 27 (57%) eyes using SAP, 19 (40%) eyes using OCT, and 17 (36%) eyes using HRT. In early NTG, SAP detected progression in 44% of eyes, and this increased to 70% in advanced NTG. In contrast, OCT and HRT detected progression in 50 and 7% of eyes during early NTG, but only 30 and 0% of eyes in advanced NTG, respectively. Among several parameters, the rates of change that differed significantly between patients with and without progression were the MD of SAP (p = 0.013), and the inferior RNFL thickness (p = 0.041) and average RNFL thickness (p = 0.032) determined by OCT. CONCLUSIONS: SAP had a higher detection rate of NTG progression than other tests, especially in patients with advanced glaucoma, when we defined progression as the enlargement of a localized RNFL defect. The rates of change of the MD of SAP, inferior RNFL thickness, and average RNFL thickness differed between NTG patients with and without progression.

Analysis of the Etiologies and the Classification of Fixed Dilated Pupil after Intraocular Surgery

PURPOSE: To seek for mechanisms to prevent fixed dilated pupil including Urrets-Zavalia syndrome after intraocular surgery by analyzing and classifying the causes of such cases. METHODS: Medical records and anterior segment photographic images of patients with fixed dilated pupil who underwent penetrating keratoplasty, lamellar keratoplasty, or cataract surgery were analyzed in a retrospective manner from April, 1984 to February, 2014. RESULTS: Among 15 cases of postoperative fixed dilated pupil, 8 eyes of keratoconus eyes had received penetrating keratoplasty done and 7 eyes with ocular disorders other than keratoconus underwent intraocular surgeries. In cases 1 and case 2, which received penetrating keratoplasty for keratoconus, dilated pupil with regular pupil border, iris atrophy, and secondary glaucoma occurred; these cases were classified as group 1 and diagnosed as Urrets-Zavalia syndrome. Cases from 3 to 8 which also received penetrating keratoplasties due to keratoconus, irregularly dilated pupil, severe iris atrophy, posterior synechiae after moderate to severe inflammation in the anterior chamber, and fibrotic membrane on the anterior capsule occurred; these cases were classified as group 2. Finally, cases 9 to 15, which had mild inflammation, no fibrotic membrane, and regularly fixed dilated pupil after receiving other intraocular surgeries were classified as group 3. CONCLUSIONS: Differences exist between definite Urrets-Zavalia syndrome and postoperative fixed dilated pupil with regards to regularity of pupillary margin, degree of iris atrophy, posterior synechiae, fibrotic membrane, and posterior subcapsular opacity. Therefore, a new classification of fixed dilated pupil after intraocular surgery which addresses these characteristics is required and various trials to prevent the adverse postoperative complications of fixed dilated pupil should be performed. Preventive measures may include careful control of intraocular pressure, restricting atropine use, completely removing of viscoelastics, and minimal air or gas injection.

The Comparison of Astigmatic Outcomes after Cataract Surgery of Inferior versus Superior Clear Corneal Incision

PURPOSE: To analyze the difference in astigmatism and the mean change in total astigmatism between inferior clear corneal incision and superior clear corneal incision following cataract surgery in surgically-induced astigmatism (SIA). METHODS: Fifty-five eyes of 55 patients with with-the-rule astigmatism >0.5 diopters were evaluated. Patients were divided into two groups according to incision location (Group 1, 26 eyes with an inferior incision; Group 2, 29 eyes with a superior incision). Patients were evaluatied one month postoperatively. Uncorrected visual acuity (UCVA, log MAR), best-corrected visual acuity (BCVA, log MAR), SIA and mean change in corneal astigmatism were measured in both groups. RESULTS: One month postoperatively, mean UCVA was 0.15 +/- 0.17 log MAR in Group 1 and 0.23 +/- 0.24 log MAR in Group 2 (p = 0.253). Mean BCVA was 0.08 +/- 0.13 and 0.08 +/- 0.12 log MAR in Groups 1 and 2, respectively (p = 0.926). The SIA was 0.50 +/- 0.17 diopter and 0.57 +/- 0.34 diopter (p = 0.253) and mean change in total astigmatism was 0.50 +/- 0.96 diopter and 0.38 +/- 0.86 diopter in Groups 1 and 2, respectively (p = 0.426). CONCLUSIONS: There was no statistically significant difference between the two groups. Thus, corneal incision on the inferior side in patients of with-the-rule astigmatism can reduce the SIA and mean change in corneal astigmatism for patients with glaucoma, hard upper eyelid tension or sunken eye.