AIM: To analyze ocular biometric parameters among candidates for cataract surgery.METHODS: This cross-sectional study was conducted on 4 607 cataract patients(4 607 eyes)in Farabi Eye Hospital, Tehran, Iran from January 2017 to September 2021. Axial length(AL), keratometry(Kf, Ks and Km), and anterior chamber depth(ACD)were assessed using IOLMaster 700. All eyes were categorized into three groups based on AL: short eyes(22 mm25 mm)and ACD as follows: low(3.00 mm3.60 mm).RESULTS: The mean age of patients was 60.3±14.1(range 8-95)years [2 243(48.69%)female and 2 364(51.31%)male]. The AL, ACD and mean keratometry ranges were 23.1 to 23.4 mm, 3.1 to 3.2 mm and 44.50 to 45.00 diopter(D), respectively. The mean amount of ACD in the long eyes group was significantly higher than the normal and short eyes group(P<0.001). The mean AL in the high ACD group was significantly higher than low and normal ACD patients(P<0.001). But the mean of Kf, Ks and Km in the low ACD and long eyes group was significantly higher than in high ACD and short AL groups(P<0.001).CONCLUSION: Those candidates with long eyes had deeper ACD with flatter cornea; while short eyes had shallower ACD with steeper cornea. Also, patients with high ACD had longer AL with flatter cornea, and patients with low ACD had lower AL with steeper cornea.

AIM: To compare the anterior and posterior corneal astigmatism and total refractive astigmatism before and after MyoRing implantation in keratoconus(KCN)patients.METHODS: In this historical cohort study, the preoperative and postoperative total refractive, anterior and posterior corneal astigmatism of KCN patients implanted with a 360-degree full-ring implant(MyoRing)were compared before and after four consecutive follow-up sessions at 3, 6, 9, and 12 mo after surgery.RESULTS: The study encompassed 79 KCN patients(85 eyes), comprising 43 males and 36 females. The mean age of the patients was 29±7.41 years, ranging from 17 to 48 years. Throughout the follow-up sessions, a gradual decrease was observed in the trend of changes for total refractive astigmatism, anterior corneal astigmatism, and posterior corneal astigmatism. Postoperatively, total refractive astigmatism measurements exhibited a significant decrease of 2.09 D at 12 mo after MyoRing implantation(4.27±3.15 vs 2.18±1.63 D, P<0.001). Additionally, post-operative measurements revealed an enhancement of approximately 3.20 D and 0.59 D for anterior and posterior corneal astigmatism, respectively [6.40±1.90 vs 3.20±1.75 D for anterior corneal astigmatism(P<0.001)and 1.30±0.55 vs 0.71±0.35 D for posterior corneal astigmatism(P<0.001)].CONCLUSION: MyoRing implantation demonstrates significant improvements in astigmatism parameters, encompassing total refractive astigmatism as well as anterior and posterior corneal astigmatism.