Central Corneal Thickness In Group Research Articles

A study to determine the effect of hydroxychloroquine (HCQ) on central corneal thickness (CCT) in patients with rheumatoid arthritis (RA).

Corneal thinning is common in rheumatoid arthritis (RA), thereby affecting the central corneal thickness (CCT). Effect of hydroxychloroquine (HCQ) in RA has abounding literature on retinal toxicity, but there is lack of data on its corneal effects. A cross-sectional study was carried out to compare CCT in RA patients before treatment initiation (Group 1) with CCT in those on HCQ for ≥3 months (Group 2). Fifty patients were enrolled in each group. The mean age was 44.36 years with similar age, gender distribution and visual acuity in both groups. The mean CCT of patients in the cohort was 521.80 µm ± 32.57 µm and 523.94 µm ± 33.40 µm in the right eye (RE) and left eye (LE), respectively. Mean CCT in Group 1 was (RE) 522.80 µm/(LE) 524.26 µm and in Group 2 was (RE) 520.80 µm/(LE) 523.62 µm, and there was no significant difference in CCT between both the groups. Median duration of HCQ usage in Group 2 was 24 months, with the median cumulative dosage being 171 g and a majority having a dosage of 200 mg/day. There was no significant correlation between the duration/cumulative dosage of HCQ intake and CCT. No corneal deposits were identified in any patient. CCT of RA patients was similar to those reported in the Indian literature. However, there was no significant change in CCT or corneal deposits identified with an HCQ dosage of 200-400 mg/day. Longer follow-up would provide clarity on the impact of duration and cumulative dosage of HCQ on corneal changes and CCT.

Şaşılık Cerrahisinin Refraksiyon Kusuru ve Ön Segment Ölçümleri Üzerine Etkisi

Aim: This study aimed to investigate the effects of horizontal strabismus surgery on refractive error and anterior segment parameters.
 Material and Methods: Fifty-four eyes of 27 patients were included in this study. Patients underwent repeated refraction measurements and anterior segment evaluation preoperatively, first week, first month, third month, and sixth month postoperatively. Patients were divided into three groups, those who underwent resection (group 1), recession (group 2), and healthy eyes without any surgical intervention (group 3).
 Results: The mean age of the patients was 24.4±11.1 years and 14 (51.9%) were female. There was a statistically significant difference in central corneal thickness in group 2 before and after surgery (p=0.037). The mean central corneal thickness was highest in the first week with 548.14±40.42 µm and lowest in the first month with 541.50±41.75 µm after surgery. There was a statistically significant difference in cell density (p=0.004) and mean cell area (p=0.004) between groups 1 and 2 in the first week after surgery. The cell density level was statistically significantly higher in group 1 in all postoperative measurements. In addition, the mean cell area level was statistically significantly lower in group 1.
 Conclusion: Strabismus surgery has an effect on anterior segment parameters in addition to correcting eye movements and visual axis. Depending on the type of intervention, the number of affected anterior segment parameters also varies. In the management of the patient in the postoperative period, the anterior segment structures should be carefully evaluated at each examination and the findings should be noted.

Comparison of surgically induced astigmatic changes after cataract surgery in post-Laser in situ keratomileusis corneas versus virgin eyes.

Postoperative refraction in modern mi-croincision cataract surgery gained extra importance in patients with the previous laser-assisted in situ keratomileusis (LASIK) surgery. The surgically induced astigmatic changes in those eyes may differ not only in magnitude but also in direction compared to virgin corneas. This study aimed to compare the surgically induced astigmatic changes after microscopic cataract surgery between post-LASIK corneas and virgin eyes. Cases that underwent microincision cataract surgery in eyes with and without previous LASIK surgery were reviewed. The demographics, the axial length at cataract surgery, the central corneal thickness, spheric and cylindric values, keratometry readings, and postoperative posterior corneal astigmatism were retrospectively evaluated. A modified Alpins method was used for astigmatic vector analysis, and baseline astigmatism, surgically induced astigmatism, difference vector, flattening effect, and torque were assessed. A total of 42 eyes from 24 subjects was evaluated. Group I consisted of 14 eyes with the previous LASIK, and Group II included 28 eyes without any refractive surgery. Preoperative mean central corneal thickness in Group I was significantly thinner (p=0.012). There was no significant difference in baseline astigmatism between the groups regarding magnitude and power vectors. After microincision cataract surgery, there were no significant differences in mean spheric and cylindric values and mean keratometry readings (all p>0.05). However, surgically induced astigmatism and difference vector were significantly higher on J45 vector component in post-LASIK eyes and microincision cataract surgery steepening effect on post-LASIK corneas was significantly higher than those in virgin eyes (p=0.001, p=0.002 and p=0.018, respectively). Cataract surgery has steepened the corneas in both groups with a significantly higher steepening effect in post-LASIK eyes. Certainly, corneal topography cataract surgery is particularly helpful to provide more precise surgically induced astigmatism interpretations.

ASSOCIATION BETWEEN DIABETES MELLITUS AND GLAUCOMA

The study's objective was to evaluate the correlation between type 2 diabetes mellitus (T2DM) and primary open-angleglaucoma (POAG).The study was conducted on 180 patients.One hundred elevenwere included in Group A after being diagnosed with T2DM. Sixty-ninesubjects diagnosed with POAG and without T2DM were included in Group B. Examination of the anterior segment, funduscopic evaluation, Optical coherence tomography(OCT) examination,and measurement of Central corneal thickness (CCT) and Intraocular pressure (IOP)weredone. International Society of Geographical and Epidemiological Ophthalmology criteria was used for defining glaucoma. American Diabetes Association criteria werefollowed for defining diabetes.A total of 180 patients were included in the study. The total participants were further divided into threegroups. Group I- subjects with T2DM (80, 44.4%), Group II- subjects with glaucoma and T2DM (30, 16.6%), and Group III- subjects with POAG and without T2DM (70,39%).The study did not confirm the association between glaucoma and T2DM. The mean IOP in Group A and B was 15.76 ± 3.09 mm Hg and 18.36 ±4.38 mm Hg, respectively. The mean CCT in Group A was 539.73±23.7 µm while in Group B was 532.16 ±20.8 µm. The strength of the correlation between glaucoma and T2DM varied with blood sugar level (p<0.001).Thus this study could not confirm the association between glaucoma and Type 2 DM.

Fuchs heterokromik iridosiklit hastalarında kornea biyomekaniği ve kornea değerlendirilmesi

Amaç: Bu çalışmanın amacı Fuchs heterokromik iridosiklit (FHİ) tanılı gözler ile sağlıklı diğer gözlerin kornealarının ve kornea biyomekanik özelliklerinin karşılaştırılmasıdır. Gereç ve Yöntem: Fuchs heterokromik iridosiklit tanılı 14 göz (Grup 1) ve sağlıklı diğer gözler (Grup 2) çalışmaya dâhil edildi. Tüm hastalara detaylı bir oftalmolojik bakıyı takiben Ocular Response Analyzer korneal biyomekanik özellikler ve speküler mikroskobi ile santral korneal kalınlık (SKK), korneal endotelyal hücre dansitesi (KEHD) değerlendirildi. Bulgular: En iyi düzeltilmiş görme keskinliği ve intraoküler basınç istatistiksel olarak benzerdi (p değerleri sırasıyla 0,077 ve 0,557). Korneal biyomekanik parametreleri olan korneal histerezis, korneal resiztans faktör, IOPcc ve IOPg değerleri her iki grupta istatistiksel olarak benzerdi (p değerleri sırasıyla; 0,521, 0,817, 0,980 ve 0,980 idi). Ortalama santral korneal kalınlık Grup 1’de 555,57±42,95 (467-626) mikron ve Grup 2’de 556,5±37,04 (480-623) mikron olarak saptandı (p=0,959). Ortalama korneal endotel hücre dansitesi Grup 1’de 2313±420,22 (1271-2717) ve Grup 2’de 2404,42±326,75 (1566-2834) hücre/mm2 saptandı (p=0,626). Sonuç: Sağlıklı gözler ile Fuchs Heterokromik İridosiklit tanılı gözler karşılaştırıldığında kornea biyomekanik parametreleri ve korneal endotel hücre dansitesi arasında anlamlı fark saptanmamıştır. Bu sonuçlar literatürdeki birçok çalışma ile çelişmekte olup daha geniş vaka serileri ile yeni çalışmalara ihtiyaç vardır.

Corneal Biomechanical Properties of Keratoconic Eyes Following Penetrating Keratoplasty.

Objectives:To investigate the corneal biomechanical properties of keratoconic eyes following penetrating keratoplasty (PKP).Materials and Methods:Thirty-five patients (70 eyes) were enrolled to this prospective study. Operated and contralateral keratoconic eyes were defined as Group 1 and 2, respectively. All patients underwent ophthalmological examination and measurements of corneal biomechanical properties by Ocular Response Analyzer (ORA), intraocular pressure (IOP) by Goldmann applanation tonometry, and central corneal thickness (CCT) by Pentacam. Shapiro-Wilk W test was performed to test normality of the data. The statistical significance was evaluated with the paired t-test and Wilcoxon signed ranks test. Pearson correlation and Spearman rho tests were used for correlation analysis.Results:The average age and male/female ratio were 31.34±11.65 (15-60) years and 21/14, respectively. The mean values of the data obtained from Group 1 and 2 respectively were: corneal hysteresis (CH): 9.35±1.66, 8.18±1.84 mmHg (p=0.013), corneal resistance factor (CRF): 9.48±1.96, 7.14±2.05 mmHg (p<0.001), IOPcc: 16.90±4.32, 14.26±3.69 mmHg (p=0.004), IOPg: 15.45±4.61, 10.91±3.97 mmHg (p<0.001), IOPapl: 14.26±3.11, 13.09±2.54 mmHg (p=0.046), and central corneal thickness (CCT): 545.64±60.82, 442.60±68.14 μM (p<0.001). The positive correlation between CH and CRF was moderate (r=0.444) in Group 1 and strong (r=0.770) in Group 2. There was a moderate negative correlation between CH and IOPcc in both groups (r=-0.426, r=-0.423), but CH was not correlated with IOPg or IOPapl in either group. There were weak to strong positive correlations between CRF and all IOP values in both groups. There was no correlation between CRF and CCT in Group 1 (r=0.075) and a very weak correlation in Group 2 (r=0.237). Only IOPcc and IOPg were strongly correlated in both groups.Conclusion:Better understanding of corneal biomechanical properties is essential for elucidating the pathophysiology and diagnosis of several corneal pathologies such as keratoconus. The biomechanical properties of keratoconic eyes seem to be closer to normal values after PKP.

Effects of Artisan aphakic intraocular lens on central corneal thickness and intra ocular pressure in pediatric eyes with crystalline subluxated lenses

Purpose:To study effects of Artisan iris fixated intraocular lens (IOL) on central corneal thickness (CCT) and intraocular pressure (IOP) in pediatric eyes with crystalline subluxated lenses.Materials and Methods:The study included 17 eyes undergoing Artisan aphakic IOL implantation after lensectomy for subluxated crystalline lenses. CCT and IOP measurements were recorded pre-operatively and post-operatively taking the mean of 4 post-operative visits. Patients were divided into Group A (n = 8) including patients with lensectomy and iris fixation of Artisan IOL as a primary procedure and Group B (n = 9) including patients in which lensectomy was carried out as a primary surgery and Artisan IOL fixation as a secondary procedure.Results:Children ranged in age from 08 years to 16 years, mean 11.59 ± 2.96 years. Follow-up period ranged from 7 months to 16 months, mean 11.24 months ± 4.27. Mean pre-operative and post-operative IOP in Group A was 14.88 ± 2.80 and 14.16 ± 0.59 respectively (P = 0.528). In Group B it was 12.44 ± 2.79 and 14.44 ± 1.15 respectively (P = 0.080). Mean pre-operative and post-operative CCT in Group A was 529.13 ± 24.23 and 529.87 ± 17.46 respectively (P = 0.674). In Group B it was 567.33 ± 29.13 and 568.83 ± 25.69 respectively (P = 0.859).Conclusions:Primary and secondary Artisan aphakic IOL implantation did not cause any significant changes in corneal thickness or IOP during the follow-up period.

Effects of inhaled fluticasone on intraocular pressure and central corneal thickness in asthmatic children without a family history of glaucoma

Purpose:The aim of this study is to report the effects of fluticasone-inhaled corticosteroid on intraocular pressure (IOP) and central corneal thickness (CCT) of asthmatic children without a family history of glaucoma.Materials and Methods:In this prospective study, 93 children were divided into two groups: 69 asthmatic children with no family history of glaucoma who were taking inhaled fluticasone propionate 250 μg daily for at least 6 months (Group 1) and 24 age-matched control subjects without asthma (Group 2). Three measurements each, of IOP and CCT, were performed with a hand-held noncontact tonometer and a noncontact specular microscope, respectively, over a 12-week period. The order of IOP and CCT measured were randomized at each visit. Between-group comparison and the relationship between CCT and IOP measurements were investigated. P < 0.05 was statistically significant.Results:The mean age was 8 ± 2.4 years (range, 5–15 years) and 9 ± 2.9 years (range, 5–15 years) for Groups 1 and 2, respectively (P = 0.1337). The mean IOP was 14 ± 3.3 mmHg (range, 10–24 mmHg) and 14 ± 2.9 mmHg (range, 11–22 mmHg) for Groups 1 and 2, respectively (P = 0.3626). The mean CCT was 531 ± 30.1 μm (range, 467–601 μm) and 519 ± 47.0 μm (range, 415589 μm) for Groups 1 and 2, respectively (P = 0.1625). There was a weak but statistically significant correlation between IOP and CCT in Group 1 (Pearson's R = 0.3580, P = 0.0025).Conclusions:Inhaled fluticasone at the regular dose used in this study over a short period (6–24 months) was not associated with a significant effect on CCT and IOP measured with noncontact devices in asthmatic children between 5 and 15 years, without a family history of glaucoma. A weak correlation between IOP and CCT values in asthmatic children did exist.

Efecto de la mitomicina C en el engrosamiento corneal tras queratectomía subepitelial con láser excimer (LASEK)

Purpose To study the effect of mitomycin C (MMC) on the corneal regrowth after laser-assisted sub-epithelial keratectomy (LASEK). Methods We performed a prospective, controlled, observer-masked study of 64 consecutive eyes scheduled to undergo LASEK to correct their myopia. The patients were divided into two age-matched groups, with group 1 including 32 eyes in which the ablation depth was ≤ 50 μm and received no MMC. Group 2 consisted of 32 eyes in which the ablation depth exceeded 50 μm and were treated with intra-operative 0.02% MMC for 30 seconds over the ablated zone. A masked observer measured the central corneal thickness (CCT) 1 and 3 months after surgery. We compared the change in CCT between both groups up to 3 months after surgery. Results The mean patient age was 31.5 years (SD 4.6) and 31.6 (SD 8.7) years in groups 1 and 2, respectively (P = .9). Group 1 showed a mean CCT of 444.0 (SD 41.3) μm one month after surgery and 450.3 (SD 43.5) μm three months after surgery ( P = .04). CCT in group 2 was 399.7 (SD 31.2) μm and 407.9 (SD 32.6) μm one and three months after surgery, respectively ( P = .006). The difference in the CCT increases between both groups was not statistically significant ( P = .6). Conclusions A single intraoperative application of 0.02% MMC for 30 seconds did not seem to cause a substantial change in the post-surgical corneal thickening expected after LASEK.

Einfluss der Hornhautdicke auf die Tonometrie

Central corneal thickness (CCT) affects IOP measurements and is an independent risk factor for the development of glaucoma. IOP measurements of all common tonometers, such as the Goldmann applanation tonometer, non-contact tonometer and rebound tonometer, are affected by CCT. Nomograms to correct IOP measurements according to CCT have been established. These nomograms lead to a reduction of the measurement error caused by CCT in groups of patients. However, one has to be aware of the fact that, in individuals, the correction of IOP measurements can even increase the deviation of the IOP measurement from the actual IOP. The effect of CCT on dynamic contour tonometry and IOP (cc) measured by ORA is negligible. CCT is an important parameter in glaucoma management and needs to be considered when interpreting IOP measurements. This can be done by using nomograms or by implementing CCT in the calculation of the individual target pressure.

New Insights Into Changes in Corneal Thickness in Healthy Mountaineers During a Very-High-Altitude Climb to Mount Muztagh Ata

To investigate the effect of very high altitude and different ascent profiles on central corneal thickness (CCT). Twenty-eight healthy mountaineers were randomly assigned to 2 different ascent profiles during a medical research expedition to Mount Muztagh Ata (7546 m) in western China. Group 1 was allotted a shorter acclimatization time prior to ascent to 6265 m. The main outcome measure was CCT. Secondary outcome measures were oxygen saturation (SpO(2)) and symptom assessments of acute mountain sickness (cerebral acute mountain sickness score). Examinations were performed at 490, 4497, 5533, and 6265 m. Central corneal thickness increased in both groups with increasing altitude and decreased after descent. In group 1 (with the shorter acclimatization), mean CCT increased from 537 to 572 microm. Mean CCT in group 2 increased from 534 to 563 microm (P = .048). The amount of decrease in SpO(2) paralleled the increase in CCT. There was no significant decrease in visual acuity. There was a significant correlation between CCT and cerebral acute mountain sickness score when controlled for SpO(2) and age. Corneal swelling during high-altitude climbs is promoted by low SpO(2). Systemic delivery of oxygen to the anterior chamber seems to play a greater role in corneal oxygenation than previously thought. Adhering to a slower ascent profile results in less corneal edema. Visual acuity in healthy corneas is not adversely affected by edema at altitudes of up to 6300 m. Individuals with more acute mountain sickness-related symptoms had thicker corneas, possibly due to their higher overall susceptibility to hypoxia.

Viscoanaesthesia in cataract surgery: a prospective, randomized clinical trial

We aimed to compare viscoanaesthesia (VisThesia) with intracameral lidocaine in cataract surgery carried out under topical anaesthesia. In this prospective study 98 patients were randomly assigned to receive VisThesia (group 1, n = 49) or 0.5 cc of 1% unpreserved lidocaine (group 2, n = 49). All surgery was carried out by one surgeon using clear corneal technique. Pachymetry, the status of the cornea and anterior chamber, and intraocular pressure (IOP) were checked pre- and postoperatively. Mean pain scores were 0.12 (maximum: 3) in group 1 and 0.37 in group 2; the difference between the groups was not statistically significant (95% confidence interval [CI] 0.003-0.487; p = 0.05). A total of 48 patients in group 1 (98%) and 49 in group 2 (100%) reported no discomfort or only mild discomfort. No significant differences in flare and cells in the anterior chamber or IOP were found between the two study groups. There was a significantly greater frequency of corneal oedema in group 1 (p = 0.001). Postoperative central corneal thickness values were also significantly higher in group 1 (95% CI 11.64-57.24; p = 0.003). Results suggest that viscoanaesthesia provides a level of comfort during cataract surgery under topical anaesthesia similar to that facilitated by intracameral lidocaine. However, patients who are given viscoanaesthesia may have increased risk for postoperative corneal oedema.

The impact of common classes of topical antiglaucoma medications on central corneal thickness

Abstract Purpose Recent studies have shown that prostaglandin analogs (PGA) may induce biochemical (via FP receptor and MMP‐2 activation) and morphological (via collagen type I contraction) changes in corneal stroma thus affecting central corneal thickness (CCT). Beta‐blockers (BB) and topical carbonic anhydrase inhibitors (CAI) were found to have rather no effect on CCT. To investigate the influence of common classes of topical antiglaucoma medications used either in monotherapy or combined therapy on CCT. Methods In a retrospective study 487 eyes from consecutive 260 patients (148F/112M) with open angle glaucoma were examined. Depending on the topical treatment they were classified into 7 groups: A/ PGA (n = 212), B/ BB (n = 54), C/ CAI (n = 36), D/ PGA + CAI (n = 25) E/ PGA + BB (n = 23) F/ BB + CAI (n = 54), G/ non‐treated (n = 83). The CCT was measured using ultrasound pachymetry Tomey AL‐2000. The central corneal power was measured with the Topcon keratometer. ANOVA analyses were used for statistical analysis. Results There were no statistically significant differences between CCT of all groups (F=1,06, p=0,3931); the lowest values were in the eyes treated with PGA + BB (535,9 nm SD 31,4) and the highest in the eyes treated with PGA + CAI (571,3 nm SD 46,3). The mean CCT in group A was 550,4 (SD 40,8), group B 552,5 (SD 34,7), group C 562,6 (SD 40,2), group D 571,3 (SD 46,3), group E 535,9 (SD 31,4), group F 559,5 (SD 32,5), group F 557,5 (SD 42,2) nm. Conclusion In this study CCT appears not to differ in eyes treated with different classes of antiglaucoma medications either in monotherapy or combined therapy. CCT of treated glaucoma eyes does not differ from CCT of untreated glaucoma eyes.

Management of Acute Corneal Hydrops Secondary to Keratoconus With Intracameral Injection of Sulfur Hexafluoride (SF6)

To report the use of sulfur hexafluoride (SF6) gas in the management of corneal edema caused by acute corneal hydrops secondary to keratoconus. Nine eyes with acute hydrops secondary to keratoconus managed by SF6 gas injected into the anterior chamber (group 1) were compared to another 9 eyes that were managed conservatively with conventional medical therapy (group 2). Of 9 eyes in group 1, 3 had 1 injection, 4 had 2 injections, and the remaining 2 had 3 injections into the anterior chamber. All the eyes in group 1 showed an early resolution of corneal edema at 4 weeks. The same was achieved in group 2 at 12 weeks. The central corneal thickness (CCT) in group 1 and group 2 was >1.0 mm at presentation. The CCT at 3 and 12 weeks in group 1 was 0.99 and 0.65 mm, respectively, whereas CCT in group 2 at 3 weeks was >1.0 mm and at 12 weeks was 0.991 mm (P = 0.001). The mean best spectacle-corrected visual acuity (BSCVA) at 12 weeks in group 1 and group 2 was 0.39 and 0.24, respectively (P = 0.016). The results were significant in favor of group 1 over group 2 both in CCT and BSCVA. Early intervention with intracameral SF6 injection is a safe and effective therapy for early reduction of corneal edema in eyes with keratoconus and acute hydrops.

Effect of mitomycin C on epithelial hyperplasia after laser‐assisted subepithelial keratectomy (LASEK)

Abstract Purpose: To study the effects of mitomycin C (MMC) on the corneal regrowth after laser‐assisted subepithelial keratectomy (LASEK). Methods: We performed a prospective, observer‐masked study of 64 consecutive eyes (64 patients) scheduled to undergo LASEK to correct myopia. The patients were divided into two age‐matched groups. 32 eyes in which the ablation depth was ≤50 μm were included in group 1 and received no MMC. 32 eyes in which the ablation depth exceeded 50 μm were included in group 2 and were treated with intraoperative MMC 0.02% for 30 seconds over the ablated zone. A masked observer measured the corneal thickness 1 and 3 months postoperatively. We compared the increase in central corneal thickness (CCT) during the postoperative period between both groups, assuming that that increment would correspond mainly to the epithelial hyperplasia that occurs after surface ablation. Results: The mean patient age was 31.5±4.6 years and 31.6±8.7 years in groups 1 and 2, respectively (P=0.9). Group 1 showed a mean CCT of 444.0±41.3 μm one month after surgery and 450.3±43.5 μm three months after surgery (P=0.04). CCT in group 2 was 399.7±31.2 μm one month and 407.9±32.6 μm three months after surgery (P=0.006). The difference between the CCT increments between both groups was not statistically significant (P=0.6). Conclusions: A single intraoperative application of MMC 0.02% during 30 seconds after laser surface ablation did not seem to cause a substantial change in the postoperative corneal thickening after LASEK.