Risk factors for corneal endothelial cell loss after phacoemulsification.

PURPOSE: The purpose of this study was to evaluate the changes in corneal endothelial cell density (CECD) occurring after cataract phacoemulsification surgery and identify factors associated with cell loss. MATERIALS AND METHODS: This was a retrospective study involving patients who underwent cataract phacoemulsification surgery between January 1, 2018, and December 31, 2018, at two private hospitals. Demographic data and biometric parameters were obtained preoperatively. Ultrasound metrics were recorded for each operation, including total on time (TOT), total equivalent power in position 3, and cumulative dissipated energy (CDE). Using corneal specular microscopy, CECD was measured preoperatively and postoperatively at 12, 24, and 36 months. Factors associated with decreased CECD were identified. RESULTS: This study included 223 eyes of 133 patients. The mean CECD was 2530.03 ± 285.42 cells/mm2 preoperatively and significantly decreased to 2364.22 ± 386.98 cells/mm2 at 12 months (P < 0.001), 2292.32 ± 319.72 cells/mm2 at 24 months (P < 0.001), and 2242.85 ± 363.65 cells/mm2 at 36 months (P < 0.001). The amount of cell loss was associated with age, gender, preoperative CECD, preoperative anterior chamber depth, lens thickness, TOT, and CDE. Using multivariate analysis, age, preoperative CECD, and TOT were identified as independent predictors for CECD loss 12 months after surgery. CONCLUSION: The greatest decrease in CECD occurred during the first year after cataract surgery, and the amount of cell loss was influenced by both baseline patient characteristics and ultrasound metrics. Longer-term prospective studies in a larger cohort may yield more information.

Changes in corneal endothelial cell density after trabeculectomy.

BACKGROUND: Glaucoma is a leading cause of blindness worldwide for which trabeculectomy is the most effective surgical intervention for advanced disease. However, trabeculectomy has been associated with alterations to corneal endothelium, including a decrease in corneal endothelial cell density (CECD). The purpose of this study was to investigate changes in CECD after trabeculectomy, and identify factors contributing to cell loss, such as pre-operative biometry and lens status. METHODS: This retrospective study included 72 eyes of 60 patients who underwent trabeculectomy between January 2018 and June 2021 at two private hospitals. Demographic and clinical data were obtained at baseline. Corneal specular microscopy was performed pre-operatively and at 6 months after surgery. CECD was evaluated and compared between groups to quantify changes to corneal endothelium and identify significant factors affecting decreases in cell density. RESULTS: Mean CECD was 2284.66 ± 375.59 pre-operatively and 2129.52 ± 401.96 after 6 months (p < 0.001). A greater decrease in CECD (p = 0.005) was observed in phakic eyes (235.45 ± 118.32) compared to pseudophakic eyes (137.82 ± 107.30). The amount of cell loss was negatively correlated with pre-operative central corneal thickness (p = 0.009) and anterior chamber (AC) depth (p = 0.033). There were no significant correlations between changes to CECD and patient age, gender, number of pre-operative glaucoma medications and number of post-operative antifibrotic agents. CONCLUSIONS: Significant decreases in CECD occurred after trabeculectomy. Less corneal endothelial cell loss occurred in pseudophakic eyes. Hence, if patients need trabeculectomy and cataract surgery, it may be better to perform cataract surgery first. Longer term studies should derive more information.

Factors contributing to long-term refractive error after cataract surgery.

PURPOSE: To evaluate factors that may influence the direction and extent of long-term refractive error after cataract surgery. METHODS: This was a retrospective observational study conducted across two private practices in Sydney, NSW, Australia. The study population consisted of patients who underwent cataract phacoemulsification surgery between January 1 and December 31, 2018. Patients who received cataract surgery combined with another procedure were excluded. Demographic and biometric data including anterior chamber depth (ACD), keratometry, central corneal thickness, axial length (AL) and lens thickness were obtained pre-operatively. Spherical equivalent (SEQ) refraction was measured at 2 months and 3 years after surgery and compared with target refraction. Factors associated with refractive error were analyzed. RESULTS: This study included 221 eyes of 122 patients. A refractive error within 1.00 D was achieved in 217 eyes (98.2%) at 3 years post-operatively. Mean prediction error decreased significantly between 2 months and 3 years after surgery irrespective of whether eyes were more myopic (p < 0.001) or more hypermetropic than predicted (p < .0001). Pre-operative ACD and ACD-to-AL ratio were significantly associated with SEQ prediction error. CONCLUSION: After cataract surgery, refractive outcomes may be influenced by ACD and ACD-to-AL ratio. The pre-operative assessment of these risk factors may better inform IOL selection in individual patients. Prospective studies in a larger cohort are required.

Changes in refraction after cataract phacoemulsification surgery.

PURPOSE: After cataract phacoemulsification surgery, spherical equivalent refraction (SER) may be affected by factors including corneal curvature, effective lens position and axial length. While refractive outcomes have been assessed in the immediate post-operative period, longer-term changes in refraction have not been reported. The purpose of this study was to investigate the timeline changes in refraction after cataract surgery over a period of 3 years. METHODS: This was a retrospective observational study that included 344 eyes of 204 patients who underwent cataract emulsification surgery between 1 January and 31 December 2018 at two private hospitals. Keratometry, anterior chamber depth (ACD), central corneal thickness (CCT) and axial length were measured at baseline and post-operatively at 1 month, 1 year, 2 years and 3 years. Changes in SER and ocular parameters were assessed at each post-operative timepoint. RESULTS: Between 1 month and 3 years post-operatively, an overall myopic shift (0.32 ± 0.21 D, p < 0.001) occurred in 33.6% of eyes and a hypermetropic shift in 45.2% of eyes (0.35 ± 0.22 D, p < 0.001). In 21.2% of eyes, there was no reported change in SER between 1 month and 3 years. Significant changes in ACD (p = 0.04) and CCT (p < 0.001) occurred during the first year after surgery. CONCLUSION: The 3-year timeline changes in SER after cataract surgery were evaluated. As hypermetropic shift was the most common refractive change observed, it may be beneficial to aim for a more myopic post-operative refraction target. Patients should be advised of the potential for refractive changes after surgery.

Quantitative and Morphological Corneal Endothelial Changes After Selective Laser Trabeculoplasty and Retinal Photocoagulation.

PURPOSE: Selective laser trabeculoplasty (SLT) and retinal photocoagulation (RP) are two common laser procedures often performed at a wavelength of 532 nm, and may affect the corneal endothelium. This study used corneal specular microscopy to determine the impact of these procedures on the corneal endothelium. DESIGN: Retrospective cohort study in a private practice. METHODS: There were 249 eyes from 136 consecutive patients who underwent SLT for open-angle glaucoma and 132 eyes from 74 patients who underwent RP included. Corneal specular microscopy was performed immediately before and after each procedure and at 1-month postprocedure. Microscopy data included quantitative measures, such as cell density and central corneal thickness, and morphological measures, including percentage of hexagonal cells and coefficient of variation in cell area. RESULTS: There was a small (just over 1%) reduction in corneal endothelial cell count from pre-SLT to post-SLT (P = 0.008), and a statistically significant recovery at 1 month (P = 0.04). Central corneal thickness also transiently increased from pre-SLT to post-SLT (P = 0.03). Although polymegathism was unchanged, changes in pleomorphism were observed (P = 0.03). The only change in the RP group was an increase in polymegathism between pre-RP and post-RP (P = 0.001). CONCLUSIONS: SLT has measurable effects on both quantitative and morphological characteristics of the corneal endothelium, which seem to be transient. RP has fewer measurable effects, likely because, although the total laser energy is similar, it is delivered over a much longer time (3 ns versus 0.1 s). The changes observed in both procedures are minor and unlikely to be of clinical significance.

Variability of Central Corneal Thickness Measurements-Comparing Zeiss IOL Master and Tomey Corneal Specular Microscope.

PURPOSE: The aim of this study was to compare the intraobserver repeatability and agreement of central corneal thickness (CCT) measurements by 2 commonly available instruments, Zeiss IOL Master 700 (SS-OCT-based optical biometry device) and Tomey corneal specular microscope EM-3000 (Noncontact specular microscopy). DESIGN: Retrospective study. METHODS: This is a retrospective analysis of data from routine clinical practice in which preoperative CCT measurements of 105 patients scheduled for cataract surgery were analyzed. Two consecutive CCT measurements were measured using Zeiss IOL Master 700 and Tomey corneal specular microscope EM-3000 by the same examiner. The repeatability of CCT measurements was analyzed by mean intraobserver difference, coefficient of repeatability (CR), and intraclass correlation. The agreement between the 2 methods was analyzed by mean difference and limits of agreement (LoA) using the Bland-Altman method. RESULTS: The mean absolute intraobserver difference between the 2 measurements by Zeiss and Tomey were 3.41 ±â€Š3.98 µm and 8.62 ±â€Š9.52 µm (P < 0.0001), respectively. For Zeiss, the CR was 10.3 µm with 95% LoA of -10.5 to 10.1 µm. For Tomey, the CR was 25.2 µm with 95% LoA of -25.2 to 25.2 µm. The mean CCT measurements ±â€Šstandard deviation by Zeiss and Tomey were 544.0 ±â€Š38.1 µm and 532.6 ±â€Š40.0 µm, respectively (P = 0.003). The 95% LoA in CCT between the 2 methods was -15.8 to 38.7 µm. CONCLUSIONS: Zeiss IOL Master 700 has superior intraobserver repeatability and consistency than Tomey EM-3000. Zeiss produced higher CCT measurements than Tomey; hence, in clinical practice, interchangeability between these 2 methods is limited.

Histopathology of Subcapsular Cataract in a Patient with Atopic Dermatitis.

PURPOSE: To report the histopathological features of anterior subcapsular cataract associated with atopic dermatitis. CASE REPORT: A 29-year-old man with atopic dermatitis presented with bilateral anterior subcapsular cataract. After routine cataract surgery, the anterior subcapsular cataractous tissue was obtained as an anterior capsulorhexis flap and prepared as a wholemount for histological analysis. The wholemount consisted of a well-demarcated central grayish-white plaque surrounded by transparent capsule, corroborating the slit-lamp biomicroscopic appearance. Higher magnification of the plaque revealed a fibrous and amorphous mass, most likely extracellular matrix owing to the presence of irregularly arranged bundled strands of fibrils, typical of collagen. Lens epithelial cells at the plaque were densely packed and myofibroblast-like and immunoreactive for alpha-smooth muscle actin. In contrast, lens epithelial cells more distant from the plaque retained their regular cuboidal arrangement and regular spacing, and were not labeled for alpha-smooth muscle actin, similar to lens epithelial cells obtained from a non-cataractous case. CONCLUSIONS: The presence of alpha-smooth muscle actin-reactive elongated cells at the plaque suggests that the cuboidal lens epithelial cells making up the anterior subcapsular cataract have transdifferentiated into spindle-shaped myofibroblastic cells that produce and deposit aberrant extracellular matrix. This transdifferentiation process, more commonly known as an epithelial-mesenchymal transition, contributes to a fibrotic response leading to the development of human anterior subcapsular cataract.

Corneal endothelial abnormalities after selective laser trabeculoplasty (SLT).

PURPOSE: Whitish spots are sometimes observed in the corneal endothelium after selective laser trabeculoplasty (SLT). To evaluate the corneal endothelium after SLT, corneal specular microscopy was performed. METHODS: A total of 142 eyes with open angle glaucoma that underwent SLT during the period of 9 months from February 10 to November 10, 2012, had their corneal endothelium examined with specular microscopy before and after SLT. RESULTS: Dark spots were observed in the corneal endothelium on corneal specular microscopy immediately after SLT. Seventy-one of the 142 eyes had no significant dark spots or increase in dark spots after SLT. Thirty-seven of the 142 eyes showed few dark spots after SLT. Thirty-four of the 142 eyes showed numerous dark spots after SLT on specular microscopy imaging, which resolved by 1 month. The last group had the greatest decrease in the corneal endothelial cell count at 1 month after SLT, but this was not statistically significant in this study (P=0.1). CONCLUSIONS: The corneal endothelial abnormalities after SLT shown in this study may be transient, and long-term effects are probably negligible in normal corneas or single treatments. However, in corneas with reduced transparency of the endothelium, such as compromised corneas and corneas with pigment deposits on the endothelium, there may be a risk of further corneal endothelial compromise, especially after repeated SLT. Larger and longer term studies with histopathologic evaluation would be useful to evaluate the effect of SLT on normal and subnormal corneal endothelium. Until further studies are done, it would be wise to minimize the number and energy of SLT laser shots.

Corneal endothelial changes after selective laser trabeculoplasty.

BACKGROUND: Whitish spots are sometimes noted in the corneal endothelium after selective laser trabeculoplasty. To evaluate the corneal endothelium after selective laser trabeculoplasty, corneal specular microscopy was performed. DESIGN: Prospective observational study in a private practice. PARTICIPANTS: Fifteen consecutive patients with open-angle glaucoma undergoing selective laser trabeculoplasty in February 2012 had their corneal endothelium examined with specular microscopy before and after treatment. METHODS: Selective laser trabeculoplasty was done with 50 ± 5 shots to 180 degrees of meshwork using 0.3-0.9 mJ of power to achieve the reaction of a hint of microbubbles in 80% of laser shots. MAIN OUTCOME MEASURES: Corneal specular microscopy photographs (0.25 × 0.54 mm) were taken prior to, immediately after and 1 month after selective laser trabeculoplasty. These photographs were assessed and graded. RESULTS: Of the 15 patients, three showed numerous, four showed few and eight showed no increase of dark spots after selective laser trabeculoplasty. All the dark spots resolved by 1 month. CONCLUSION: The effect of selective laser trabeculoplasty on the corneal endothelium may be transient, and long-term effects are probably negligible in normal corneas. However, in compromised corneas and corneas with pigment deposits on endothelium, there may be a risk of corneal endothelial compromise, especially after repeated selective laser trabeculoplasty. Larger and longer term studies with histopathological evaluation would be useful to evaluate the effect of selective laser trabeculoplasty on normal and subnormal corneal endothelium. Until further studies are done, it would be wise to minimize the number and energy of laser shots.

Detection of cutaneous HPV types 4 and 24 DNA sequences in breast carcinoma in Singaporean women of Asian ancestry.

AIM: To date, there have been conflicting data on the prevalence of HPV in primary breast carcinoma, with a median prevalence of 35%. We believe that the low prevalence reported could be due to use of inappropriate amplification primers and methods of detection. We designed a study to detect and reflect more accurately the incidence of both mucosal and cutaneous HPV types in breast carcinoma among Singaporean women. METHODS: In our study, we used two different molecular techniques, both of which involved a polymerase chain reaction (PCR) amplification step for any HPV DNA found in the breast cancer tissues. The first method targeted primarily the mucosal HPV types, and the second, primarily the cutaneous HPV types. Formalin-fixed, paraffin-embedded breast cancers were used for the studies. The first method involved the GP5+/GP6+ primers for PCR amplification and a commercially available HPV DNA genotyping chip for detection. The subsequent studies involved the use of the FAB 59/64 primers for amplification, followed by DNA sequencing and comparison to the NCBI GenBank database for the detection of all possible HPV types. RESULTS: With the first technique, all 92 breast cancers tested gave negative results for HPV DNA, suggesting the absence of HPV types in breast cancers. Using the second method, we detected HPV sequences in 32/92 (35%) samples, of which 28 were shown to be HPV-4, one was HPV-24, two had mixed HPV types and one had an indeterminate HPV sequence that did not match any of the HPV sequences deposited in the GenBank database. CONCLUSIONS: These results were consistent with our hypothesis that the true incidence of HPV in breast carcinoma is much higher than those reported to date, and that this is probably due to the limited sensitivity of the molecular techniques used in earlier studies.