Investigation Of Demography And Clinical Characteristics Of Patients With Keratoconus

Objective1.To investigate the demography and clinical characteristics of patients with KC, discussing the diagnosis and therapeutic evidence of KC.2.To examine both eyes of a patient with KC by Pentacam, and evaluate characteristics of the quantitative parameters and analyze the correlation among them, providing theorical evidences for the early diagonosis of KC.Methods1.We collected and analyzed the informations of demography of KC patients, including the morbidity ratio of male and female, the morbidity age,and so on. A t the same time, the clinical characteristics were analyzed and compared:medical history, family history, history of wearig spectacles or contact lens, refraction state, examination of slit lamp, systemic diseases history. VF-14questionaire survey was proceeded, and the results were analyzed finally.2.109eyes of68patients with KC were examined by OCULUS pentacam,63patients109eyes could be obtained corneal topography,10eyes of5patients can not be obtained images. Then, we evaluated characteristics of the quantitative parameters of corneal topography and analyzed the correlation among them.64patients(64eyes, all of eyes are left eye) with moderate or high myopia were selected as normal control eyes and comparison analysis were made between them. All of the data were analyzed by the SPSS17.0statistical software package.Results1.Incidence in male was significantly higher than in female (67.6%vs32.4%, P<0.05). In this study age onset of patients definitely diagnosed with keratoconus was26.00±8.91(ranging from12.38to51.12) in which10%(7/68) smaller than18year-old,57.6%(39/68) younger than30year-old.2. The chief complaint of patients, when they first come to see the ophthalmologist, were decreased vision (83.8%, it could not be corrected by spectacles), progressed myopia (22.1%), headache and ophthalmodynia(5.9%). Asymptomic patients were5.9%. One of the68patients had family history of KC. The most common symptom was conical protrusion (59.1%), Fleischer’s ring was seen in53%patients and Vogt’s lines were seen in26%patients. The mean cylinder in confirmed KC group was significantly higher than suspected group (-4.00D vs-2.00D, p<0.001) while Best corrected visual acuity was better in suspected KC group than in confirmed group (0.04vs0.18, p<0.001).3.The final scores of VF-14questionaire ranged from8.3to100, with68%of patients scoring between91and100,13%scoring between81and90and19%scoring80or worse. Aalmost half(46.8%) had some difficulty with reading small print, with a considerable number reporting at least moderate difficulty (28patients,25.7%). Almost a third of patients had some difficulty reading news-print or books, doing fine handwork or watching television, and at least moderate difficulty was encountered by22.9%,19.3%and21.1%of patients, respectively. A number of patients also had some difficulty with traffic or store signs (31.2%), diffi-culty seeing steps, stairs or curbs (24.8%) and difficulty recognizing people at close range (17.4%).4.There was no significant difference between suspected KC group and KC group in anterior maximum diopter and anterior maximum elevation (P>0.05) However, there was significant difference between KC group and suspected KC group, control group (P<0.05)5.The posterior maximum diopter and elevation of keratoconus and suspected keratoconus group are higher than control group. There are significant difference in multiple comparison between keratoconus group, suspected keratoconus group and control group(P<0.05).6.Corneal thinnest point decreases progressively from control group to keratoconus group, and in multiple comparison between these three groups, significant difference can be found(P<0.05). The posterior maximum diopter and elevation are not in the center of cornea.7.In keratoconus group, the anterior maximum diopter has significant correlation with anterior maximum elevation, posterior maximum elevation, posterior maximum diopter, corneal thinnest point (P<0.0001). In suspected keratoconus group, anterior maximum diopter has correlation with posterior maximum elevation, corneal thinnest point (P<0.05)8.The distance from the thinnest point to the corneal center of clinical keratoconus group, subclinical keratoconus group and normal group was (0.76±0.42) mm、(0.66±0.38) mm and (0.61±0.29) mm, respectively. Most of the corneal thinnest point of clinical/subclinical keratoconus eyes was in the inferior tempus, the normal group was in the1mm ring region.Conclusions1.Young people around20years old showed higher incidence of keratoconus in this study; the patients who have the complains of high myopia development and uncorrected by conventional lenses should be highly suspected; the popularity of RGP can improve the best corrected visual acuity of keratoconus eye and extend the time of corneal transplant.2.Vision function damage caused by keratoconus can resulted in a certain extent damage of daily activities related to the vision.3.When diagnosing keratoconus, we should comprehensively analyze the corneal thinnest point, anterior and posterior diopter and elevation. If the posterior maximum diopter and elevation were increased, and the corneal thinnest was decreased, we should highly suspect as keratoconus.4.With the progressive of keratoconus, local protrusion of corneal will aggravate, cornea will thin gradually, and the increase of corneal diopter is correlation with the protrusion of posterior surface and thinning of the corneal apex.5.The corneal thinnest point of keratoconus eyes has peripheral trend, and is not in the center area. When the corneal thinnest point is outside the central corneal1mm circle, and located in the area of inferior temple, much more attention should be paid, screening keratoconus further by combination other corneal topographic map parameters.