Objective: To determine the effect of corneal collagen cross-linking on the corneal curvature of eyes with keratoconus measured using an Oculus Pentacam® at 2 years and annually thereafter. Methods: This was a descriptive, retrospective study involving patients with keratoconus who had undergone uncomplicated collagen cross-linking using the Dresden protocol from January 2012 to March 2016. Baseline measurements of best-corrected visual acuity (BCVA), maximum K value (Kmax), corneal astigmatism, anterior and posterior elevation map changes were recorded and compared with data taken at 2 and 3 years Results: This study included 32 patients (48 eyes) with a mean follow-up of 28.88 ± 6.23 months. Only 4 patients (6 eyes) had 3-year follow-up data with a mean follow-up of 42.83 ± 4.58 months. When all eyes were considered, significant changes were noted in Kmax, BCVA, and anterior and posterior elevation maps between baseline and 2-year follow-up. Specifically, there were significant decreases in Kmax (p<0.0001) and anterior elevation (p<0.05), and significant improvement in BCVA (p<0.01) while posterior elevation (p<0.0001) was found to have increased significantly at 2nd year follow-up compared to baseline. When only eyes with 3-year follow-up data was analyzed, only BCVA showed significant change (p<0.05). Corneal astigmatism remained stable during the study period. Conclusion Two to 3 years after collagen cross-linking for keratoconus, corneal curvature parameters and BCVA showed improved and stable outcomes when compared to baseline.
Keratoconus ; Astigmatism

No Abstract Available.
Fas Ligand Protein* ; Keratoconus*

Objectives: This study described the clinical profile of patients with keratoconus at a single tertiary referral hospital. Methods: This was a single-center, retrospective, cross-sectional study that reviewed medical records of patients diagnosed with keratoconus from January 2015 to August 2022. Data on the clinical profile, intervention, and clinical outcomes were collected from the chart review. Results: Forty (40) patients (79 eyes) were included in the study. Majority (98%) had bilateral disease in which 22 (55.5%) were affected asymmetrically. The mean age was 21 years. Most patients (72.5%) were male. Blurring of vision was the chief complaint in all patients. Atopy was present in 23 patients (57.5%). History of vigorous eye rubbing was present in 31 (77.5%). The mean interval from onset of symptoms to consult was 46.4 ± 33.38 months. The mean pinhole corrected distance visual acuity was 0.47 ± 0.41 (Snellen equivalent of 20/59). The average spherical equivalent was -7.48D ± 6.99D. Corneal protrusion on slit-lamp biomicroscopy was seen in 78 eyes (98.7%). Other findings included Fleischer ring (53.2%), Vogt's striae (19.0%), and apical corneal scar (24.0%). Only one eye (1.3%) had no corneal findings. Thirty-nine eyes (49.3%) were classified as advancedsevere keratoconus. Rigid contact lens was planned for 60 eyes (75.9%). Sixty-two eyes (78.5%) were for collagen cross-linking. Deep anterior lamellar keratoplasty was planned in 10 eyes (12.7%) and penetrating keratoplasty in two eyes (2.5%). Conclusion Keratoconus at the Philippine General Hospital was most frequently seen in young males and asymmetrically affects both eyes. Patients consulted relatively late and presented with a more advanced stage of the disease. History of ocular allergy and eye rubbing were significant risk factors. Improving awareness of this condition must be emphasized to detect keratoconus earlier.
Keratoconus ; Cornea ; Demography ; Philippines

PURPOSE: To compare changes of anterior and posterior corneal elevation, and sagittal curvature according to the severity of keratoconus and to compare differences between keratoconus and normal cornea. METHODS: A total of 81 eyes diagnosed with keratoconus and 20 eyes of normal subjects were evaluated with a Pentacam Scheimpflug camera. The keratoconus eyes were divided into 3 groups according to mean keratometer (K): mild (K < or = 47.0 diopters (D)), moderate (47.0 to 52.0 D), and severe (52.0 D> or =). The following parameters were obtained to evaluate the correlation of keratoconus: corneal thickness, anterior and posterior corneal elevation, and sagittal curvature. RESULTS: Out of 81 keratoconus eyes, 56 eyes were mild, 12 eyes were moderate, and 13 eyes were severe keratoconus. The mean central corneal keratometer, anterior and posterior corneal elevation, and sagittal curvature of the keratoconus eyes were 49.7 D, 22.07 microm, 38.16 microm, 52.76 D and the values increased statistically compared to the normal eyes. Furthermore, the values increased significantly with the severity of keratoconus. ROC curve analysis showed the estimated meaningful value for anterior and posterior corneal elevation and sagittal curvature of keratoconus for diagnosis; there were no diagnostic values for corneal thickness and refractive power. CONCLUSIONS: The index of 5.5 microm for mean anterior elevation, 12.5 microm for mean posterior elevation, and 44.5 microm for mean sagittal curvature using the Pentacam(R) are useful to diagnose keratoconus. Variation of anterior and posterior elevation, and sagittal curvature measured by Pentacam(R) are useful in understanding the process of keratoconus.
Cornea ; Eye ; Keratoconus ; ROC Curve

Posterior lenticonus is a circumscribed round or oval bulge of posterior lens capsule and cortex. About 100 cases have been reported since the first clinical description given in 1888 by Meyer. Most cases in the literature were unilateral and were not usually associated with other congenital anomaly. The authors have recently experienced a case of bilateral posterior lenticonus with left keratoconus in a 21 year-old male patient and two cases of characteristic posterior lenticonus not associated with other ocular anomalies in 22 year-old male patients.
Humans ; Keratoconus ; Male ; Young Adult

PURPOSE: To investigate new diagnostic criteria of keratoconus using Orbscan II Slit Scanning Corneal Topography/Pachymetry System. METHODS: Eighty eyes of 45 patients with keratoconus and 100 randomly selected eyes of 50 patients without any ophthalmologic problem were enrolled in this study. Anterior elevation from BFS, posterior elevation from BFS, Sim K (maximum), and thinnest pachymetric value were evaluated using Orbscan II. Values outside 2 standard deviations from the mean value of each parameter were estimated to the upper or lower limits in diagnosing keratoconus. RESULTS: There were significant differences of all parameters of Orbscan II between the keratoconic eyes and the control (p<0.001). Keratoconus could be diagnosed with 86.3% sensitivity and 99.0% specificity when 3 or more criteria were satisfied and with 96.3% sensitivity and 99.0% specificity when 2 or more criteria were satisfied out of the following 4 criteria; anterior elevation from BFS > 23.3 micro meter, posterior elevation from BFS > 49.8 micro meter, Sim K (maximum) > 47.0 D, thinnest pachymetric value < 455.0 micro meter. CONCLUSIONS: Orbscan II can provide useful information in the diagnosis of keratoconus with high sensitivity and specificity.
Diagnosis ; Humans ; Keratoconus* ; Sensitivity and Specificity

PURPOSE: To compare the effect of posterior corneal astigmatism on the estimation of total corneal astigmatism using anterior corneal measurements (simulated keratometry [K]) between eyes with keratoconus and healthy eyes. METHODS: Thirty-three eyes of 33 patients with keratoconus of grade I or II and 33 eyes of 33 age- and sex-matched healthy control subjects were enrolled. Anterior, posterior, and total corneal cylinder powers and flat meridians measured by a single Scheimpflug camera were analyzed. The difference in corneal astigmatism between the simulated K and total cornea was evaluated. RESULTS: The mean anterior, posterior, and total corneal cylinder powers of the keratoconus group (4.37 ± 1.73, 0.95 ± 0.39, and 4.36 ± 1.74 cylinder diopters [CD], respectively) were significantly greater than those of the control group (1.10 ± 0.68, 0.39 ± 0.18, and 0.97 ± 0.63 CD, respectively). The cylinder power difference between the simulated K and total cornea was positively correlated with the posterior corneal cylinder power and negatively correlated with the absolute flat meridian difference between the simulated K and total cornea in both groups. The mean magnitude of the vector difference between the astigmatism of the simulated K and total cornea of the keratoconus group (0.67 ± 0.67 CD) was significantly larger than that of the control group (0.28 ± 0.12 CD). CONCLUSIONS: Eyes with keratoconus had greater estimation errors of total corneal astigmatism based on anterior corneal measurement than did healthy eyes. Posterior corneal surface measurement should be more emphasized to determine the total corneal astigmatism in eyes with keratoconus.
Astigmatism* ; Cornea ; Humans ; Keratoconus* ; Meridians

PURPOSE: To compare the biomechanical properties of keratoconus, keratoconus suspect, and normal subjects measured by ocular response analyzer. METHODS: A total of 72 patients were divided into 3 groups: keratoconus, suspected keratoconus, and normal control subjects. The 3 age-matched groups were evaluated according to age, sex, and visual acuity. Slit lamp examinations, Pentacam, and ocular response analyzer (ORA) examinations were performed. Mean corneal refractive power, central corneal thickness, corneal hysteresis (CH), and corneal resistance factor (CRF) were evaluated and analyzed. RESULTS: Twenty-four eyes were included in each group. The mean age was 23.8 years in keratoconus, 26.0 years in suspected keratoconus and 26.1 years in normal subject groups. Mean corneal refractive power was significantly higher in keratoconus (p < 0.001) and suspected keratoconus (p = 0.001) groups than in the normal subject group. Mean central corneal thickness showed significant differences among the 3 groups (p < 0.05). CH was significantly lower in keratoconus than suspected keratoconus (p = 0.025) and normal subject groups (p = 0.005), but showed no significant difference between suspected keratoconus and normal subject groups. CRF showed significant differences among all 3 groups (p < 0.05). CH and CRF had negative correlations with mean corneal refractive power and positive correlations with central corneal thickness. CONCLUSIONS: CH and CRF measured by ORA were significantly different between keratoconus and normal subject groups and had significant correlations with mean corneal refractive power and central corneal thickness. CRF may be a useful method to differentiate between suspected keratoconus and normal cornea patients.
Cornea ; Eye ; Humans ; Keratoconus ; Visual Acuity

PURPOSE: To compare corneal topographic changes using Orbscn II between keratoconus and keratoconus- suspected eyes. METHODS: Thirty-seven keratoconus eyes, 17 keratoconus-suspected eyes and 37 normal eyes were evaluated by using Orbscan II corneal topography. We compared central phachymetry, anterior elevation from best-fit sphere (BFS), posterior elevation from BFS, most protruded corneal thickness, central corneal thickness, anterior chamber depth, corneal diameter, and pupil size. RESULTS: Central pachymetry, anterior and posterior elevation from BFS, central corneal thickness, and anterior chamber depth were statistically significantly different between keratoconus and control eyes. Anterior elevation from BFS showed a significant difference between keratoconus-suspected and control eyes. There were statistically significant differences in central pachymetry, posterior elevation from BFS, central corneal thickness and most protruded corneal thickness between keratoconus and keratoconus-suspected eyes. Corneal diameter and pupil size showed no differences among the 3 groups. CONCLUSIONS: Suspected keratoconus eyes have a higher value of anterior elevation from BFS on Orbscan II topography as compared with control eyes. Central pachymetry, posterior elevation from BFS, central corneal thickness and most protruded corneal thickness may be helpful in distinguishing between keratoconus and keratoconus-suspected eyes.
Anterior Chamber ; Corneal Topography ; Keratoconus* ; Pupil

Radial keratotomy has not been used to treat keratoconus. A 20-year-old male with keratoconus underwent a radial keratotomy to achieve satisfactory vision. Immediately after the operation visual acuity was improved, but one year later acute hydrops was developed for unknown reasons. Therefore, the authors report it with review of the literatures.
Edema* ; Humans ; Keratoconus* ; Keratotomy, Radial* ; Male ; Visual Acuity ; Young Adult