Thasarat S. Vajaranant

Visual Acuity and Intraocular Pressure after Descemet's Stripping Endothelial Keratoplasty in Eyes with and without Preexisting Glaucoma

PURPOSE (1) To characterize the pattern of intraocular pressure (IOP) changes after Descemets stripping endothelial keratoplasty (DSEK) in patients without preexisting glaucoma and in those with preexisting glaucoma, with and without prior glaucoma surgery. (2) To compare vision and IOP outcomes among the 3 groups. DESIGN A retrospective chart review. PARTICIPANTS A total of 805 DSEK cases performed in 641 patients by a single surgeon from December 2003 to August 2007 were available in the database. Only the first-treated eye of each patient with at least 1-year follow-up was included. Four hundred cases qualified: 315 eyes had no glaucoma (C); 64 eyes had glaucoma with no previous glaucoma surgery (G); and 21 eyes had prior glaucoma surgery (GS). Eyes with preexisting retinal problems were included in the analysis. METHODS Data analysis included calculation of incidence of postoperative IOP elevation. The study criteria for postoperative IOP elevation were IOP > or =24 mmHg or IOP increase > or =10 mmHg from baseline. Kruskal-Wallis test was used to compare visual acuity (VA) and IOP among the 3 groups preoperatively and at 1-, 3-, 6-, and 12-month postoperative visits. MAIN OUTCOME MEASURES Visual acuity (Snellen) and IOP (millimeters of mercury). RESULTS The incidence of postoperative IOP elevation by the study criteria was 35%, 45%, and 43% for groups C, G, and GS, respectively. Elevated IOP was medically managed by initiating or increasing glaucoma medications or reducing steroids in 27%, 44%, and 38% of the patients in groups C, G, and GS, respectively. A subsequent glaucoma procedure was performed in 0.3%, 5%, and 19% of patients in groups C, G, and GS, respectively. Only the control group had statistically significant IOP elevation at 12 months (median increase of 2 mmHg) when compared with baseline (P<0.0001). All 3 groups had statistically significant improvement in vision at 12 months when compared with baseline (12-month median VA = 20/40 for C and G; and 20/50 for GS, P<0.0001). CONCLUSIONS All groups had a substantial incidence of IOP elevation after DSEK. Close monitoring of IOP is warranted. In this cohort, preexisting glaucoma did not seem to have a negative effect on VA after DSEK. FINANCIAL DISCLOSURE(S) Proprietary or commercial disclosure may be found after the references.

Intraocular Pressure Measurements Following Descemet Stripping Endothelial Keratoplasty

PURPOSE The effect of increased corneal thickness after Descemet stripping endothelial keratoplasty (DSEK) on intraocular pressure (IOP) measurement has not been previously studied. It is uncertain if this increase in corneal thickness would artificially elevate IOP reading by Goldmann tonometry [GAT] (Haag-Streit, Konig, Switzerland). Therefore the effect of DSEK-related thick cornea on IOP measurement was investigated using three different techniques. DESIGN Prospective cross-sectional study. METHODS Participants were recruited from a single tertiary referral center. Fifty eyes of 38 patients with successful DSEK at least three months prior to testing were evaluated. At the time of the study, none of the participants had clinically detectable corneal edema. IOP was measured with GAT, pneumatonometry, and dynamic contour tonometry (DCT) in an unmasked randomized sequence. Central corneal thickness (CCT) was measured by ultrasonic pachymetry. RESULTS Mean CCT was 701 +/- 68 microm. The mean IOP +/- standard deviation (SD) was 15.9 +/- 4.9 mm Hg for GAT, 20.3 +/- 4.5 mm Hg for pneumatonometry, and 19.8 +/- 4.4 mm Hg for DCT. Pneumatonometry and DCT IOP measurements were significant higher than GAT (P < .01). In contrast, the difference between pneumatonometry and DCT readings was not statistically significant (P = .28). The correlations between IOP and corneal thickness were not significant in this cohort (P > .05). CONCLUSIONS Falsely elevated GAT, as expected in thick corneas, was not demonstrated after DSEK. High IOP reading by GAT therefore should raise suspicion of elevated IOP in DSEK eyes.

Gender and glaucoma: what we know and what we need to know

Purpose of review With growing aging populations and an increase in cases of glaucoma and glaucoma blindness worldwide, aging populations are particularly at higher risk of glaucoma and glaucoma blindness. Awareness of the gender differences might increase attention toward populations at risk. Recent findings Women not only outlive men, but also outnumber men in glaucoma cases worldwide. Women are at higher risks for angle closure glaucoma, but there is no clear gender predilection for open angle glaucoma. Of interest, there is some evidence suggesting that female sex hormones might be protective of the optic nerve. In addition, it is hypothesized that decreased estrogen exposure is associated with increased risk for open angle glaucoma, yet population-based studies present inconsistent results. Presently, there is insufficient evidence to support hormonal replacement therapy use in glaucoma prevention. In addition, it appears that women carry a larger burden of glaucoma blindness due to longevity and disadvantages in socioeconomic/health beliefs. Summary Current evidence suggests that older women are at risk for glaucoma and glaucoma blindness. Further interdisciplinary research involving investigators, specialized in glaucoma, womens health and health disparities, will lead to better understanding of gender health disparities in glaucoma and better targeting populations at risk.

The Changing Face of Primary Open-Angle Glaucoma in the United States: Demographic and Geographic Changes From 2011 to 2050

PURPOSE To examine how demographic and geographic variations in US populations from 2011 to 2050 will contribute to estimated numbers of primary open-angle glaucoma (POAG) cases. DESIGN Cross-sectional study. METHODS Prevalence rates from selected population-based studies were used to estimate the number of persons aged 40 years and older with POAG in the United States. For calculation, the age-, sex-, and race/ethnicity-specific prevalence rates were multiplied by the US Census estimates and projections from 2011 to 2050. Main outcome measures are estimated numbers of persons with POAG in different age, sex, and racial/ethnic groups and total and per capita POAG rates by state. RESULTS In 2011, 2.71 million persons in the United States have POAG, with the highest estimated number among populations aged 70 to 79 years (31%), women (53%), and non-Hispanic whites (44%). The largest demographic group is non-Hispanic white women. In 2050, an estimated 7.32 million persons will have POAG, with the highest number among populations aged 70 to 79 years (32%), women (50%), and Hispanics (50%). The largest demographic group will shift to Hispanic men. During the next 40 years, the highest per capita POAG rates will double in New Mexico, Texas, and Florida. CONCLUSIONS Despite the high prevalence of POAG in African Americans and Hispanics, the largest group in the United States is currently among older non-Hispanic white women but is expected to shift to Hispanic men over the next few decades. Given this shift, the greatest yield from screening programs is likely to be in those states with high numbers of non-Hispanic white women and Hispanic men.

Detection using the multifocal electroretinogram of mosaic retinal dysfunction in carriers of X-linked retinitis pigmentosa

PURPOSE To examine whether a mosaic pattern of retinal dysfunction in obligate carriers of X-linked retinitis pigmentosa (XLRP) could be observed in local electroretinographic responses obtained with the multifocal electroretinogram (mfERG). DESIGN Prospective observational case series. PARTICIPANTS Five obligate carriers of XLRP (mean age, 53.2 years) were recruited into the study. METHODS Examination of each subject included a complete ocular examination, Humphrey visual field, standard full-field electroretinogram (ERG), and mfERG testing. For the mfERG, we used a 103-scaled hexagonal stimulus array that subtended a retinal area of approximately 40 in diameter. The amplitudes and implicit times in each location for the mfERG was compared with the corresponding value determined for a group of normally sighted, age-corrected control subjects. MAIN OUTCOME MEASURES Mapping of 103 local electroretinographic response amplitudes and implicit times within the central 40 with the multifocal electroretinogram. RESULTS Localized regions of reduced mfERG amplitudes and/or delayed implicit times were found in four of five carriers. In one of these four carriers, a mosaic pattern of mfERG dysfunction was present even in the absence of any clinically apparent retinal changes, retinal sensitivity losses on Humphrey field testing, or abnormal full-field cone ERG responses. However, one carrier with a typical tapetal-like reflex demonstrated no deficit on any functional tests. CONCLUSIONS The mfERG demonstrated patchy areas of retinal dysfunction in some carriers of XLRP. This mosaic pattern of dysfunction may be observed in some patients with a normal-appearing fundus, normal psychophysical thresholds, and normal amplitude and implicit time full-field ERG cone responses.

Estrogen deficiency accelerates aging of the optic nerve

AbstractThe aim of this study was to provide a comprehensive review on hormone-based pathophysiology of aging of the optic nerve and glaucoma, including a literature review and expert opinions. Glaucoma, a group of intraocular pressure-related optic neuropathies, is characterized by the slow progressive neurodegeneration of retinal ganglion cells and their axons, resulting in irreversible visual sensitivity loss and blindness. Increasing evidence suggests that glaucoma represents the accelerated aging of the optic nerve and is a neurodegenerative disease of the central nervous system. This review highlights the high burden of glaucoma in older women and the importance of understanding the hormone-related pathophysiology of optic nerve aging and glaucoma in women. Strong epidemiological, clinical, and experimental evidence supports the proposed hypothesis that early loss of estrogen leads to premature aging and increased susceptibility of the optic nerve to glaucomatous damage. Future investigations into the hormone-related mechanisms of aging and glaucoma will support the development of novel sex-specific preventive and therapeutic strategies in glaucoma.

Localized retinal dysfunction in central serous chorioretinopathy as measured using the multifocal electroretinogram

PURPOSE To determine the extent of electrophysiologic dysfunction in patients with central serous chorioretinopathy (CSC). DESIGN Prospective observational case series. PARTICIPANTS Six patients with unilateral CSC (mean age, 40 years) were recruited into the study. METHODS Six patients with CSC underwent multifocal electroretinogram (mfERG) testing on both their clinically affected and opposite uninvolved eyes using the VERIS System, with a stimulus array of 103 scaled hexagons. The first positive peak responses were analyzed within six concentric ring annuli centered on the fovea. Amplitudes and implicit times were compared with those of an age-similar control group. MAIN OUTCOME MEASURES Local electroretinographic response amplitudes and implicit times within the central 40 degrees with the mfERG. RESULTS All the clinically uninvolved eyes showed mfERG amplitudes and implicit times within the normal range throughout the central 40 degrees of the retina. All six eyes with CSC showed reduced amplitudes and/or delayed implicit times that were limited to the regions of the macula in which clinical changes associated with CSC were apparent. CONCLUSIONS We observed electroretinographic changes only in the clinically affected eyes, and these were limited to regions with ophthalmoscopically apparent fundus changes. Our findings do not support the conclusion that functional impairment, as measured by the mfERG, in eyes with CSC extends beyond clinically observed fundus changes. We did not observe abnormal mfERG responses in the clinically normal eyes of such patients.

Visual Impairment and Blindness in Adults in the United States: Demographic and Geographic Variations From 2015 to 2050

IMPORTANCE The number of individuals with visual impairment (VI) and blindness is increasing in the United States and around the globe as a result of shifting demographics and aging populations. Tracking the number and characteristics of individuals with VI and blindness is especially important given the negative effect of these conditions on physical and mental health. OBJECTIVES To determine the demographic and geographic variations in VI and blindness in adults in the US population in 2015 and to estimate the projected prevalence through 2050. DESIGN, SETTING, AND PARTICIPANTS In this population-based, cross-sectional study, data were pooled from adults 40 years and older from 6 major population-based studies on VI and blindness in the United States. Prevalence of VI and blindness were reported by age, sex, race/ethnicity, and per capita prevalence by state using the US Census projections (January 1, 2015, through December 31, 2050). MAIN OUTCOMES AND MEASURES Prevalence of VI and blindness. RESULTS In 2015, a total of 1.02 million people were blind, and approximately 3.22 million people in the United States had VI (best-corrected visual acuity in the better-seeing eye), whereas up to 8.2 million people had VI due to uncorrected refractive error. By 2050, the numbers of these conditions are projected to double to approximately 2.01 million people with blindness, 6.95 million people with VI, and 16.4 million with VI due to uncorrected refractive error. The highest numbers of these conditions in 2015 were among non-Hispanic white individuals (2.28 million), women (1.84 million), and older adults (1.61 million), and these groups will remain the most affected through 2050. However, African American individuals experience the highest prevalence of visual impairment and blindness. By 2050, the highest prevalence of VI among minorities will shift from African American individuals (15.2% in 2015 to 16.3% in 2050) to Hispanic individuals (9.9% in 2015 to 20.3% in 2050). From 2015 to 2050, the states projected to have the highest per capita prevalence of VI are Florida (2.56% in 2015 to 3.98% in 2050) and Hawaii (2.35% in 2015 and 3.93% in 2050), and the states projected to have the highest projected per capita prevalence of blindness are Mississippi (0.83% in 2015 to 1.25% in 2050) and Louisiana (0.79% in 2015 to 1.20% in 2050). CONCLUSIONS AND RELEVANCE These data suggest that vision screening for refractive error and early eye disease may reduce or prevent a high proportion of individuals from experiencing unnecessary vision loss and blindness, decrease associated costs to the US economy for medical services and lost productivity, and contribute to better quality of life. Targeted education and screening programs for non-Hispanic white women and minorities should become increasingly important because of the projected growth of these populations and their relative contribution to the overall numbers of these conditions.

Intravitreal Bevacizumab for Neovascular Glaucoma

PURPOSE To report 6-month and 1 year outcomes of eyes treated for neovascular glaucoma (NVG) with intravitreal bevacizumab injection and panretinal laser (PRP) compared to those receiving PRP alone. DESIGN retrospective, consecutive case series. METHODS Charts of patients with NVG from retinal ischemia and at least 6 months of follow-up were reviewed. Patients were treated with one injection of 1.25 mg intravitreal bevacizumab followed by PRP or with PRP alone. The primary outcome was the long-term angle anatomy. Secondary measures included intraocular pressure (IOP), visual acuity, patient compliance, and control of systemic diseases. RESULTS Fourteen eyes of 12 patients treated with bevacizumab and PRP and 15 eyes of 11 patients treated with PRP alone were included in the study. Mean sectors of open angle at baseline was 1.31 in the bevacizumab group and 1.47 in the retinal ablation group (P = 0.73). Mean sectors of open angle was 2.14 and 1.18 in the bevacizumab and retinal ablation groups, respectively (P < 0.05) at 6-month follow-up, and 2.27 and 1.18, respectively (P < 0.05) at 1-year follow-up. Mean baseline IOP was 32.3 mmHg (+/-14.8) in the bevacizumab group and 31.8 mmHg (+/-13) in the PRP group (P = 0.75). At 6-month follow-up, the mean IOP was 18.28 mmHg (+/-10) in the bevacizumab group and 23.33 mmHg (+/-14.6) in the PRP group (P = 0.05), and 19.12 mmHg (+/-6.8) and 26.2 mmHg (+/-18) (P = 0.1), respectively at 1-year follow-up. Nineteen patients were judged to be noncompliant, 10 had uncontrolled diabetes and 7 had uncontrolled hypertension. CONCLUSIONS This study documents better long-term preservation of open angle and IOP control in eyes receiving bevacizumab along with PRP. We stress that NVG is still associated with poor visual acuity outcomes.

Sequential multifocal electroretinogram findings in a case of Purtscher-like retinopathy.

PURPOSE To report the multifocal electroretinographic findings of a patient with pancreatitis-associated Purtscher-like retinopathy. DESIGN Observational case report. METHODS A 20-year-old man with a history of alcohol abuse and acute pancreatitis underwent multifocal electroretinography (mfERG; 103-scaled hexagons, 8-minute recording time) at 1 week, 4 weeks, and 6 months after the onset of the retinopathy. RESULTS At 1 week, the patient had extensive cotton- wool spots in the posterior pole bilaterally, and visual acuity was significantly reduced. Both the A-waves and B-waves of the mfERG were depressed in the corresponding areas. At 4 weeks, neither visual acuity nor mfERG showed improvement, although the cotton-wool spots had resolved. Interestingly, at 6 months, visual acuity had improved significantly in the left eye, consistent with increased ratios of mfERG responses for the central area. CONCLUSION There was no selective reduction of b-waves of the mfERG as anticipated in isolated inner retinal pathology. In this case, both the A-waves and B-waves were reduced, suggesting damage to both outer and inner retinal layers.