Significant Increase In Central Corneal Thickness Research Articles

Changes and Influencing Factors of Corneal Endothelial Cells and Central Corneal Thickness after Pediatric Cataract Surgery.

This study aimed to examine the impact of cataract surgery on the corneal endothelium and central corneal thickness (CCT) in pediatric patients, and to identify the factors associated with corneal alterations. This retrospective study included consecutive children undergoing bilateral or unilateral cataract surgery and intraocular lens (IOL) implantation at the Eye Hospital of Wenzhou Medical University, with or without posterior capsulorhexis and anterior vitrectomy, and an age-matched normal control group. This study aimed to assess whether changes in corneal parameters, including CCT, corneal endothelial cell density (CD), average cell area (AVE), standard deviation of size (SD), coefficient of variation (CV), percentage of hexagonal cells (6A) before and after surgery, and endothelial cell loss (ECL) differed among the bilateral cataract, unilateral cataract, and control groups. Furthermore, the potential effects of anterior vitrectomy, axial length (AL), preoperative anterior chamber depth (ACD), surgical duration, horizontal corneal diameter (HCD), intraoperative pupil diameter (PD), and the number of corneal sutures on corneal endothelial parameters and CCT were investigated. A total of 107 eyes from 107 children were included in the study. In the bilateral cataract group, CD significantly decreased, AVE and CCT significantly increased, and ECL was significantly higher than in the control group. The unilateral cataract group also exhibited a significant increase in CCT. Additionally, the numberofcornealsutures was negatively correlated with CD, and PD was negatively correlated with CV in the unilateral cataract group. Cataract surgery in pediatric patients results in increased CCT, reduced CD, and morphological changes in corneal cells. A greater number of corneal sutures and a smaller PD increased the risk of CD reduction and elevated CV in the unilateral cataract group, underscoring the need for ophthalmologists to minimize corneal damage in these children.

The effect of sodium hyaluronate on dry eye and corneal epithelial thickness following cataract surgery.

To evaluate the effects of sodium hyaluronate drops on dry eye parameters and corneal epithelial thickness following cataract surgery. The study included 84 patients who underwent uncomplicated phacoemulsification. In Group A, 0.15% sodium hyaluronate drops were added to the postoperative antibiotic/anti-inflammatory treatment. In Group B, only antibiotic/anti-inflammatory treatment was applied. Preoperatively and at 1week and 1month postoperatively, all the patients were evaluated in respect of tear break-up time (TBUT), the Schirmer test under anesthesia, the corneal fluorescein staining (CFS) score, mean central corneal thickness (CCT) and mean central corneal epithelial thickness (CCET), and the two groups were compared. A statistically significant difference was determined between the two groups at postoperative 1month in respect of TBUT, Schirmer test, CFS score, and CCET (p < 0.01). In Group A, a statistically significant increase was determined in the TBUT and Schirmer values at 1month postoperatively (p < 0.01, p = 0.01, respectively) and in Group B, these values were decreased compared to preoperatively (p < 0.01). The CCET was determined to be significantly thinner in Group B 1month postoperatively (p < 0.01). A significant increase in CCT was observed in both groups at postoperative 1week (p < 0.01) and preoperative values were reached at 1month postoperatively. In the patient group using sodium hyaluronate, significant differences were determined in all dry eye parameters and CCET. The use of hyaluronate sodium drops after cataract surgery was seen to improve dry eye parameters and contribute to a healthy ocular surface by ensuring continuity of the corneal epithelium.

Corneal Biomechanical Evaluation After Meniscus-Shaped Stromal Lenticule Addition Keratoplasty (MS-SLAK) for Keratoconus.

To evaluate corneal biomechanical changes after meniscus-shaped stromal lenticule addition keratoplasty (MS-SLAK) performed for the treatment of keratoconus. This interventional study included patients affected by advanced keratoconus (stage III and IV) who underwent examination with a dynamic Scheimpflug analyzer and non-contact tonometer (Corvis ST; Oculus Optikgeräte GmbH) at baseline and 12 months after MS-SLAK. The biomechanical parameters evaluated in this study were integrated inverse radius (1/R), deformation amplitude ratio (DA ratio), stiffness parameter at first applanation (SP-A1), biomechanical intraocular pressure (bIOP), central corneal thickness (CCT), and stress-strain index (SSI). Sixteen patients were enrolled in the study. The analysis was ultimately conducted on 15 patients. Comparative analyses showed an increase in corneal stiffness as demonstrated by a rise in SSI (P < .0001) and SP-A1 (P < .0001) and a decrease in DA ratio (P < .0001) and 1/R (P = .01). A significant increase in CCT was found (P < .0001). No statistically significant modification was found for bIOP (P = .43). The corneal biomechanical analyses evaluated by the Corvis ST showed that MS-SLAK for advanced keratoconus is able to increase corneal overall stiffness. This result is explained by the significant increase in thickness induced by MS-SLAK. [J Refract Surg. 2023;39(7):499-504.].

Hydro-implantation versus Visco-implantation of Intraocular Lenses and Fluid Load Effect on Corneal Endothelial Cells after Uneventful Phacoemulsification

AIM: The purpose of the study was to study the effect of implantation method and fluid load (aspiration time, aspiration volume) on corneal endothelium in uneventful phacoemulsification surgeries. METHODS: This study was a prospective and interventional study involved 77 eyes, 50−81 years, divided into three groups according to implantation method (on Saline, Healon, or Methylcellulose). Specular microscope analysis of corneal endothelial parameters: Cell density (CD), central corneal thickness (CCT), coefficient of variation (CV), and Hexagonality (HEX) were done before and 3 months after surgery. RESULTS: A total of 77 eyes with cataracts were studied, and there was a significant increase in CCT and CV with a decrease in CD and HEX in all three groups. On comparing the same parameters between the three groups, there were insignificant differences regarding CCT and HEX changes. Although there was a significant change in CD, the highest loss was in the Healon group (median −0.138), followed by the Saline group (median −0.118), and the lowest was in the Methyl group (median −0.075). There was a significant change in CV, showing the highest increase in the Healon group (median 0.16129) followed by the Saline group (median 0.13307) and the lowest in the Methyl group (median 0.1266). There was a non-significant change in all corneal parameters among cases in each group with different aspiration volumes and times. CONCLUSION: Endothelial cell loss was lowest with Methyl followed by saline, and highest with Healon implantation. Fluidics had an insignificant effect in the three groups. Saline implantation was comparable to Healon, with an insignificant difference in CD loss.

SPECULAR MICROSCOPY OF CORNEAL ENDOTHELIUM IN PATIENTS WITH TYPE I DIABETES MELLITUS VERSUS NORMAL PERSONS

Background: Diabetes mellitus is a general disorder that changes the main metabolic processes that distressing the functions of systems in the body. Type 1 diabetes is the generally common metabolic disorder of adulthood. Around one in each 400–600 juveniles and adults has type 1 diabetes. Its incidence has risen over new years. Objective: To evaluate corneal endothelial alterations in type I diabetic patients with or without diabetic retinopathy. Patients and Methods: A prospective comparative study of 60 subjects divided into two equal groups: Group A: with type I DM with or without diabetic retinopathy and Group B: normal persons matched with age and sex. All patients were subjected to full history and ophthalmic examination including Uncorrected / best corrected visual acuity (UCVA/BCVA) expressed in LogMar scoring, refraction using automated refractometer (Topcon KR-800 Auto refractometer), intraocular pressure (IOP) measurement by Goldman Applanation tonometer, Slit lamp biomicroscopy to assess corneal clarity, depth of anterior chamber, state of pupil dilatation, lens morphology, state of diabetic retinopathy in dilated pupil fundus examination and non-contact specular microscope (Topcon sp-1p, Topcon Medical Inc., Japan) to assess the corneal endothelium and patients were compared to normal persons as regard: endothelial cell density (ECD), coefficient of variation in cell size (CV), changes in percentage of hexagonal cells (HEX) and central corneal thickness (CCT). The study was done at Department of ophthalmology, Sayed Galal University Hospital, Cairo, Egypt and it was carried out from May 1ˢ, 2019 to April 30 2020. Results: Among patient group, twenty one (70%) patients were females while nine (30%) patients were males. Ten persons (20 eyes) in study group were diabetics with diabetic retinopathy. There was a significant decrease in ECD, and a significant increase in CCT, also there was a significant change in CV, and HEX an increase in CV (polymegathism) and decrease in hexagonality (pleomorphism) in type I diabetic patients. Diabetic retinopathy and duration of diabetes were factors that affect central corneal thickness. Conclusion: Cornea of a diabetic patient has lower ECD compared to normal and thicker cornea than non-diabetics also with higher coefficient of variation and lower hexagonality.

Effect of Scleral Lens Wear on Central Corneal Thickness and Intraocular Pressure in Patients With Ocular Surface Disease.

To determine the effect of scleral lens wear on central corneal thickness (CCT) and intraocular pressure (IOP). Twenty-five subjects (46 eyes), fit with scleral lenses that ranged in diameter from 17.0 to 18.0 mm, were included in this retrospective study at the University of Southern California, Department of Ophthalmology. All subjects had ocular surface disease and were categorized into the following groups based on etiology of their dry eye: chronic graft versus host disease, Stevens-Johnson syndrome, Sjögren syndrome, or general dry eye syndrome. Measurements of CCT and IOP were obtained at the initial scleral lens consultation (pre-CCT and pre-IOP) and at follow-up visits (post-CCT and post-IOP) immediately after lens removal. The total average difference between pre-CCT and post-CCT was 7.19 μm (544.90±31.29 vs. 552.09±30.30 μm), which was a statistically significant increase of 1.01% (P≤0.05). On the other hand, the total average difference between pre-IOP and post-IOP was -0.89 mm Hg (14.47±3.63 vs. 13.58±3.61 mm Hg), which was not statistically significant (P≥0.05). There were no statistically significant correlations between change in CCT (ΔCCT) and visual acuity (P≥0.05), between ΔCCT or change in IOP (ΔIOP) in relation to lens diameter (P≥0.05), between etiology of dry eye affecting ΔCCT or ΔIOP (P≥0.05), between wearing time today and ΔCCT or ΔIOP (P≥0.05), and between average wearing time (AWT) and ΔCCT (P≥0.05). In addition, there was no statistically significant correlation between AWT and ΔIOP (R=0.0796) over a range of wear time hours. There was a statistically significant increase in CCT after scleral lens wear in subjects with ocular surface disease, which may be attributed to subclinical hypoxic conditions created by scleral lens wear. No significant relationship was found between scleral lens wear and IOP.

Evaluation of central corneal thickness as measured by pentacam and retinal and choroidal thickness as measured by optical coherence tomography before and after uneventful cataract phacoemulsification in normal and diabetic patients without retinopathy

Introduction Cataract phacoemulsification surgery is the commonest ophthalmological surgical procedure performed worldwide. In spite of the relative short duration, small incision, and relative low power used during the procedure, it causes an inflammatory reaction, compression, and hypoxia to the tissues. Every step of this maneuver can cause direct effects on tissue and ocular pressure fluctuation, which may lead to disruption of the corneal endothelium, blood–aqueous barrier, and blood–retinal barrier, leading to postoperative corneal edema, increased macular, and choroidal thickness. Purpose The purpose of this study was to evaluate central foveal thickness (CFT) changes and subfoveal choroidal thickness (SFCT) changes using spectral domain optical coherence tomography and central corneal thickness (CCT) changes using Pentacam, before and after cataract surgery, and to compare the results between two groups, that is, normal and diabetic patients without retinopathy. Patients and methods A prospective study was conducted, in which 40 eyes of 40 patients, 20 nondiabetic and 20 diabetic without retinopathy, who underwent cataract phacoemulsification were examined preoperatively, 1 week postoperatively, and 1 month postoperatively. The study was done in Kobri El-Kobba Military Hospital during the period from May to November 2017. Results Preoperative CCT was significantly higher in diabetic group than the nondiabetic group. There was also a significant increase in CCT 1 week postoperatively in both group, reaching its peak, and then gradual decrease to near preoperative values 1 month postoperatively. There was no significant difference in preoperative and postoperative CFT values between the two groups. CFT continued to increase till 1 month postoperatively reaching values significantly higher than preoperative values at 1 week and 1 month postoperatively. The preoperative SFCT was significantly higher in diabetic group than the nondiabetic group with no significant differences in the postoperative values between the two groups; it also continued to increase till 1 month postoperatively, reaching values significantly higher than preoperative values at 1 week and 1 month postoperatively. Conclusion Cataract phacoemulsification leads to temporary increase in CCT and long-term increases in CFT and SFCT in both diabetic and nondiabetic patients. Diabetic patients have higher central corneal thickness and higher SFCT than nondiabetics.

Effects of primary selective laser trabeculoplasty on anterior segment parameters.

To investigate the effects of selective laser trabeculoplasty (SLT) on the main numerical parameters of anterior segment with Pentacam rotating Scheimpflug camera in patients with ocular hypertension (OHT) and primary open angle glaucoma (POAG). Pentacam measurements of 45 eyes of 25 (15 females and 10 males) patients (12 with OHT, 13 with POAG) before and after SLT were obtained. Measurements were taken before and 1 and 3mo after SLT. Pentacam parameters were compared between OHT and POAG patients, and age groups (60y and older, and younger than 60y). The mean age of the patients was 57.8±13.9 (range 20-77y). Twelve patients (48%) were younger than 60y, while 13 patients (52%) were 60y and older. Measurements of pre-SLT and post-SLT 1mo were significantly different for the parameters of central corneal thickness (CCT) and anterior chamber volume (ACV) (P<0.05). These parameters returned back to pre-SLT values at post-SLT 3mo. Decrease of ACV at post-SLT 1mo was significantly higher in younger than 60y group than 60y and older group. There was no statistically significant difference in Pentacam parameters between OHT and POAG patients at pre- and post-treatment measurements (P>0.05). SLT leads to significant increase in CCT and decrease in ACV at the 1(st) month of the procedure. Effects of SLT on these anterior segment parameters, especially for CCT that interferes IOP measurement, should be considered to ensure accurate clinical interpretation.

Effect of Glyceraldehyde Cross-Linking on a Rabbit Bullous Keratopathy Model.

Background. To evaluate the effects of corneal glyceraldehyde CXL on the rabbit bullous keratopathy models established by descemetorhexis. Methods. Fifteen rabbits were randomly divided into five groups. Group A (n = 3) is the control group. The right eyes of animals in Groups B,C, D, and E (n = 3, resp.) were suffered with descemetorhexis procedures. From the 8th day to the 14th day postoperatively, the right eyes in Groups C and D were instilled with hyperosmolar drops and glyceraldehyde drops, respectively; the right eyes in Group E were instilled with both hyperosmolar drops and glyceraldehyde drops. Central corneal thickness (CCT), corneal transparency score, and histopathological analysis were applied on the eyes in each group. Results. Compared with Group A, statistically significant increase in CCT and corneal transparency score was found in Groups B, C, D, and E at 7 d postoperatively (P < 0.05) and in Groups C, D, and E at 14 d postoperatively (P < 0.05). Conclusion. Chemical CXL technique using glyceraldehyde improved the CCT and corneal transparency of the rabbit bullous keratopathy models. Topical instillation with glyceraldehyde and hyperosmolar solutions seems to be a good choice for the bullous keratopathy treatment.

Monitoring of strain-dependent responsiveness to TLR activation in the mouse anterior segment using SD-OCT.

To determine whether spectral-domain optical coherence tomography (SD-OCT) can be used to longitudinally monitor inflammation in the mouse anterior segment and to identify any strain-dependent differences in responsiveness to distinct toll-like receptor (TLR) ligands. Corneal inflammation was induced in BALB/c and C57BL/6 mice following central corneal abrasions and topical application of saline, TLR-4 ligand, lipopolysaccharide (LPS), or TLR-9 ligand, CpG-oligodeoxynucleotide (CpG-ODN; CpG). Anterior-segment images were captured using SD-OCT at baseline, 24 hours, and 1 week post treatment. Corneal thickness, stromal haze, and the number of keratic precipitates (KP) and anterior chamber (AC) cells were longitudinally compared to determine differences between mouse strains, time points, and TLR activation. In both mouse strains, treatment with CpG, but not saline or LPS, resulted in a similar number of KPs and AC cells. In C57BL/6 mice, central corneal thickness (CCT) increased in CpG- and LPS-treated eyes at 24 hours, which normalized by 1 week. In BALB/c mice, a significant increase in CCT occurred in eyes treated with CpG at 1 week. Stromal haze peaked in C57BL/6 eyes treated with LPS- or CPG-treatment at 24 hours; however, BALB/c eyes showed persistent and marked increases in corneal haze compared with baseline at 1 week post treatment. Spectral-domain OCT enables high-resolution, longitudinal, in vivo imaging of anterior segment inflammation in mice and revealed novel strain- and time-dependent differences in response to distinct TLR activation in the cornea.

Corneal endothelial morphology and central thickness in patients with type II diabetes mellitus

To investigate corneal endothelial cell density and morphology in type II diabetic and non-diabetic patients and to relate potential differences to the glycaemic status. A prospective clinical study including 107 patients with type II diabetes and 128 non-diabetic patients. Sample size was based on a power calculation (power = 0.90; p = 0.05). The diabetic patients had on average more than four HbA1c tests performed (mean 4.1; range 2-14) with intervals of at least 3 months as a reflection of the long-term glycaemic status. The controls had no diabetes confirmed by two causal blood tests. The endothelial cell density, the variation in endothelial cell size (CV), the percentage of hexagonal cells, and the central corneal thickness (CCT) were recorded. Type II diabetic subjects did not differ from the non-diabetic control subjects with regards to endothelial cell density, hexagonality or variation in CV, but showed a significant increase in CCT (538 versus 546 μm, p < 0.05). In the diabetic group, lower cell counts were associated with higher HbA1c values (p < 0.05). The HbA1c did not, however, have any impact on the CCT. Type II diabetes has no impact on corneal cell density or morphology in subjects with good glycaemic status. However, higher HbA1c was associated with lower endothelial cell density. CCT was significantly increased in the diabetic group.

Evaluation of limbal and pars plana silicone oil removal in aphakic eyes

To compare limbal and pars plana silicone oil removal (SOR) in aphakic eyes and to evaluate the acute effect of silicone oil flow to the corneal endothelium. Sixteen aphakic patients with silicone oil endotamponade requiring SOR were recruited for this prospective study and randomly scheduled for limbal or pars plana SOR. The central corneal thickness (CCT), visual acuity (VA) and intraocular pressure were measured preoperatively, on the first postoperative day and 4 months after surgery. Endothelial cell density (ECD) was measured preoperatively and at the end of follow-up. The in vitro study was performed on ten enucleated porcine eyes. Corneoscleral discs were prepared and fixed on artificial anterior chamber followed by 2.5-mm limbal incision and 5-ml silicone oil injection in six cases and 5 ml balanced salt solution (BSS) in four cases. The ECD decreased by 239.2 ± 86.7 (13.9%) and 86.7 ± 22.4 cells/mm(2) (5%) after limbal (n = 8) and pars plana SOR (n = 8), respectively (p < 0.001 for both). The difference between the groups was significant (p < 0.001). A significant increase in CCT and corresponding decrease in VA was noted on the first postoperative day using both procedures. At the end of follow-up, the CCT and VA were comparable to initial values. Postoperative hypotony (≤6 mmHg) was observed more frequently after limbal SOR. In the experiment, lamellar abrasions of corneal endothelium were observed after silicone oil injection, whereas no changes were observed after BSS injection. Limbal SOR causes more considerable damage to the corneal endothelium than the pars plana approach because of mechanical abrasion.

The effect of prostaglandin analogues on central corneal thickness of patients with chronic open-angle glaucoma: a 2-year study on 129 eyes

To evaluate the effect of prostaglandin analogues on the central corneal thickness (CCT) of patients with chronic open-angle glaucoma (COAG). One hundred and twenty-nine eyes were included in this study. Of these, 108 were treated with prostaglandin analogues (latanoprost, travoprost and bimatoprost), while 21 eyes treated with β-blockers were used as controls. CCT was measured before treatment and at 3-month intervals. A slight but significant increase in CCT was recorded in the bimatoprost and latanoprost groups. Treatment with bimatoprost produced a constant increase (1.85-8.83 μm) in CCT at all time-points of the study. The CCT rise found in the latanoprost group was significant for the first year. Treatment with travoprost did not affect CCT. The possibility of corneal thickening under prolonged, local prostaglandin treatment should be investigated further. However, in clinical practice, CCT changes may sometimes influence intraocular pressure measurements significantly.

Corneal Thickness at High Altitude

The eye, like other organs, is affected by the hypobaric hypoxia of high altitude. Corneal swelling is known to occur under hypoxic conditions at sea level, for instance when wearing contact lenses. The aim of this study was to measure central corneal thickness (CCT) in lowlanders ascending to altitude. The Apex 2 medical research expedition provided the opportunity to measure CCT in 63 healthy lowlanders. The subjects arrived in La Paz, Bolivia (3700 m), where they spent 4 days acclimatizing before being driven over 2 hours to the Cosmic Physics Laboratory at Chacaltaya (5200 m), where they stayed for 7 days. CCT was measured in the early afternoon by using ultrasound pachymetry on the first, third, and seventh day at 5200 m and before and after the expedition at sea level. Mean CCT increased significantly from 543 microm at sea level to 561 microm on the first day at 5200 m (P < 0.001). This continued to increase to 563 microm on the third day and 571 microm on the seventh day but returned to 541 microm after descent to sea level. This study showed that altitude caused a significant increase in CCT in a large group of healthy lowlanders with normal corneas. This finding confirms the results of previous studies and is likely to be caused by endothelial dysfunction causing stromal swelling. This could potentially cause visual problems for high-altitude mountaineers among whom refractive surgery is popular.