Lipid accumulation and protein modifications of Bruch’s membrane in age-related macular degeneration

AIM: To investigate the association of axial length (AL), lens thickness (LT) and lens vault (LV) with postoperative anterior chamber angle metrics after laser peripheral iridotomy (LPI). METHODS: Prospective observational study of 69 patients (97 eyes) were diagnosed as primary angle closure suspect (PACS), primary angle closure (PAC) or primary angle-closure glaucoma (PACG). AL, LT, central anterior depth (ACD), angle opening distance (AOD), trabecular iris angle (TIA), and angle recess area (ARA) were measured before and 1wk after LPI. The association between AL, LT, LV with ACD, AOD, TIA, ARA were analyzed by comparing the differences between preoperative and postoperative measurements for anterior segment biometric parameters. RESULTIS: ACD, AOD, TIA, and ARA were significantly increased after LPI (P<0.05). Greater LT was significantly associated with greater postoperative increases in ACD, AOD, TIA, and ARA (all P＜0.05). AL was not significantly associated with changes of anterior segment biometric parameters. Greater LV was significantly associated with greater postoperative increases in ACD, AOD, and TIA (all P＜0.05), but was not significantly associated with changes of ARA. CONCLUSION: Greater baseline LT and LV measurements are associated with greater increases in anterior segment biometric parameters after laser peripheral iridotomy. AL are not associated with the change of anterior segment biometric parameters.     

Comparison of Anterior Segment Optical Coherence Tomography and Ultrasound Biomicroscopy for Iris Parameter Measurements in Patients with Primary Angle Closure Glaucoma

Purpose: To compare the repeatability and consistency of anterior segment optical coherence tomography (AS-OCT) and ultrasound biomicroscopy (UBM) in measuring iris parameters in patients with primary angle closure glaucoma. Methods: Twenty-two patients (38 eyes) with primary angle closure glaucoma,including 5 eyes with acute angle closure glaucoma,10 fellow eyes of acute angle closure glaucoma, and 23 eyes with chronic angle closure glaucoma, were recruited consecutively in our hospital. All subjects underwent anterior scanning by AS-OCT and UBM. Peripheral iris thickness (PIT) and iris curvature (IC) in the anterior segment image obtained by AS-OCT and UBM were measured twice. The reproducibility of these two scans was evaluated by the intraclass correlation coefficient (ICC). A paired t-test was used to compare the difference between the two scans and the 95% limits of agreement (LoA) were calculated. Results:The ICCs of PIT and IC measured by UBM were 0.892 and 0.936 respectively, while for AS-OCT these values were 0.629 and 0.859, respectively. UBM had a higher reproducibility in both PIT and IC measurements as compared with AS-OCT.Differences in PIT measurement between AS-OCT and UBM(P=0.331).were not statistically significant, the 95% LoA (-0.178～0.156) mm was 36.1～41.2% of the mean. The IC was 0.053 mm smaller when measured by UBM than by AS-OCT (P=0.017), with the 95% LoA (-0.100～0.206) mm, or 36.2～74.6% of the mean.Conclusion:UBM had a higher reproducibility in measuring iris parameters than AS-OCT. The consistency between AS- OCT and UBM in measuring iris parameters was low in primary angle closure glaucoma patients. (Eye Science 2013; 28:1-6)     

Ultrasonic Evaluation of the Lens Thickness to Axial Length Factor in Primary Closure Angle Glaucoma

Ultrasonic biometry was done in 232 normal eyes and 138 eyes with primary angle closure glaucoma (ACG), using Ultrascan Digital B System IV (10 MHz). The ratio between the lens thickness and the axial length (lens thickness to axial length factor, LAF) was evaluated as a biometric index for assessing the eye with primary ACG in Chinese. LAF of 2.00 was found to be ideal point of demarcation between ACG and normal eyes (i.e., lens thickness equals to 1/5 of axial length). It appears that LAF is helpful in screening primary ACG eyes from eyes of the general population. This is similar to the anterior chamber depth of 2.5 mm which is recognized as a threshold for the occurrence of primary angle closure glaucoma.     

白内障超声乳化人工晶状体植入联合房角分离术治疗闭角型青光眼临床观察

目的 观察白内障超声乳化人工晶体植入联合房角分离术治疗合并有白内障的原发性闭角型青光眼的效果.方法 回顾2006年6月至2009年6月经治疗的原发性闭角型青光眼合并白内障35例(38只眼),行透明角膜切口晶状体超声乳化吸出、后房型人工晶状体植入术联合房角分离术.观察手术前后视力、眼压、前房深度、前房角及视野的变化,并分析术后并发症.随访6个月至3年.结果 术后随访期间所有术眼眼压较术前显著降低,中央前房深度明显增加,30只眼(占79%)房角完全开放,36只眼(94%)最佳矫正视力比术前提高.结论 白内障超声乳化人工晶状体植入联合房角分离术能有效降低眼压、加深前房、开放房角和提高视力,是有效安全的手术方法.

Abstract：

Objective To observe the clinical effects ofphacoemulsification and intraocular lens implantation combined with goniosychialysis for treatment of angle-closure glaucoma.Methods From June 2006 to June 2009,35 cases (38 eyes) of primary angle-closure glaucoma with cataract were performed phacoemulsification and intraocular lens implantation combined with goniosychialysis.The changes of vision,intraocular tension,anterior chamber depth,anterior chamber angle and visual field before and after operation were observed,while the postoperative complications were analyzed.The period of follow-up was six months to three years.Results The intraocular tension of 38 eyes remarkably decreased and the anterior chamber depth obviously increased,compared with that before surgery.The anterior chamber angles of 30 eyes (79%)were completely open and the optimal corrected vision of 36 eyes (94%) improved in different degrees.Conclusions Phacoemulsification and intraocular lens implantation combined with goniosychialysis is a safe and effective surgery for treatment of angle-closure glaucoma,which can effectively decrease intraocular tension,deepen anterior chamber,open anterior chamber angle and improve vision.     

Association between choroidal thickness and anterior chamber segment in eyes with narrow or open-angle

AIM: To investigate the relationship between choroidal thickness and anterior chamber segment in subjects with eyes with narrow or open-angle. METHODS: The subfoveal choroidal thickness was measured with enhanced depth-imaging optical coherence tomography and anterior chamber parameters were measured with ultrasound biomicroscopy in one eye of 23 subjects with open-angle eyes and 38 subjects with narrow-angle eyes. The mean age was 59.52±7.04y for narrow-angle subjects and 60.76±7.23y for open-angle subjects (P=0.514). Multivariate linear regression analysis was performed to assess the association between choroidal thickness and narrow-angle parameters. RESULTS: There were no differences in subfoveal choroidal thickness between open- and narrow-angle subjects (P=0.231). Anterior chamber parameters, including central anterior chamber depth, trabecular iris angle, iris thickness 500 µm from the scleral spur (IT500), and ciliary body thickness at 1 mm and 2 mm from the scleral spur (CBT1, CBT2) showed significant differences between the two groups (P<0.05). Subfoveal choroidal thickness showed negative correlation (β=-0.496, P=0.016) only with anterior chamber depth in the open-angle group and with age (β=-0.442, P=0.003) and IT500 (β=-0.399, P=0.008) in the narrow-angle group. However, subfoveal choroidal thickness was not correlated with trabecular iris angle, anterior chamber depth, ciliary body thickness, or central corneal thickness in the narrow-angle group. CONCLUSION: Choroidal thickness does not differ in the two groups and has not correlated with anterior chamber parameters in narrow-angle subjects, suggesting a lack of relationship between choroidal thickness and primary angle-closure glaucoma.     

Mechanism and Etiology of Primary Chronic Angle Closure Glaucoma

The ocular anatomic features, pupil-blocking force, status of angle synechiae closure and positivity of provocative tests were compared between the primary chronic angle closure glaucoma (PCACG) and primary a-cute angle closure glaucoma (PAACG) by using ultrasonic biometry, computerized anterior ocular segment image processing technique, gonioscopy and provocative tests. The studies showed that the anterior chamber depth of PAACG was shallower than that of PCACG; the pupil-blocking force of PAACG was stronger than that of PCACG; the status of angle synechiae closure of PCACG were mainly creeping synechiae closure; the positivity of mydriasis test was much higher (46. 01%) in PCACG than that (6. 8%) in PAACG after iridectomy. These facts suggest approximately half of the PCACG cases may be multi-mechanism to contribute to the angle closure besides the mechanism of pupillary block. Therefore, the authors emphasis that the pupillary block must be eliminated as well as the other mechanism for the treatment     

Uveal effusion following acute primary angle-closure: a retrospective case series

AIM: To evaluate the morphological changes in anterior segment in Chinese patients with uveal effusion (UE) after the attack of acute primary angle-closure (APAC) using ultrasound biomicroscopy (UBM), and to assess the clinical course and prognosis of the disease. METHODS: In a retrospective case series, 26 eyes in 26 consecutive patients diagnosed with UE after the treatment of intraocular pressure (IOP)-lowering medication for the attack of APAC were enrolled. The unaffected fellow eyes served as controls. The morphological changes were observed by ultrasonography, slit lamp microscopy and gonioscopy. UBM was used to assess the degree and extent of effusion based on the analysis of parameters associated with UE. RESULTS: The mean IOP was 9.2 (SD 2.1) mm Hg at the diagnosis of UE after IOP-lowering medication, while 14.1 (SD, 2.6) mm Hg in the fellow eyes (P=0.000). The anterior chamber depth (ACD) (P=0.000), angle opening distance at 500 μm (AOD500) (P<0.01) and anterior chamber angle (ACA) (P<0.05) were decreased significantly, while ciliary body thickness (CBT) (P<0.05) increased significantly in UE eyes. UE grade analysis showed 7 eyes in grade 1, 9 eyes in grade 2, and 10 eyes in grade 3. Quadrant scores were performed of 4 eyes in 1 quadrant, 3 eyes in 3 quadrants, and 19 eyes in 4 quadrants. There was the positive correlation between grade and quadrant score (r=0.644, P=0.000). The effusion on all eyes were recovered after medication, which mean IOP was 13.9 (SD, 2.8) mm Hg. CONCLUSION: UE is a frequent complication in Chinese patients after the attack of APAC, partially associated with hypotony. The severity of UE is correlation with height of effusion, extent of detachment, and shallower ACD.     

New Management of Angle—closure Glaucoma by Phacoemulsification with Foldable Posterior Chamber Intraocular Lens Implantation

Objective: To investigate the management oi angle-closure glaucoma byphacoemulsification with foldable posterior chamber intraocular lens (PC-IOL)implantation.Design: Retrospective, noncontrolled interventional case series.Participants: In 36 eyes with angle-closure glaucoma (ACG) , there were 18 eyes withprimary acute angle-closure glaucoma (PACG) , 14 eyes with primary chronicangle-closure glaucoma (PCCG) , 3 eyes with secondary acute angle-closure glaucoma(SACG) and 1 eye with secondary chronic angle-closure glaucoma (SCCG).Intervention: Phacoemulsification with posterior chamber intraocular lens implantation.Main Outcome Measures: Postoperative visual acuity, IOP, axial anterior chamberdepth.Results: After a mean postoperative follow-up time of 8. 81±7. 45 months, intraocularpressure was reduced from a preoperative mean of 23. 81 ±17. 84 mmHg to apostoperative mean of 12. 54 4. 73 mmHg ( P =0. 001). Mean anterior chamber depthwas 1. 75 ± 0. 48 mm preoperatively and 2. 29 ?0. 38 mm postoperatively     

Clinical Analysis of Steroid Glaucoma

Purpose:The authors accumulated 15 cases (26 eyes) of steroid glaucoma due to topical administration of dexamethasone or prednisolone.Methods: From 1970 to 1990,26 eyes in 15 cases were observed (bilateral 11 cases,unilateral 4 cases) including 12 right eyes and 14 left eyes. 10 cases were male and 5 cases female with age ranging from 14 to 52 years averaging 28 years. 25 eyes had the manifestation of chronic open angle glaucoma in the clinical course, and 1 eye simulated an acute glaucoma attack.Results: All patients had taken antiglaucoma medication before coming to our hospital,but the IOP was over 6. 7 kPa in 9 eyes. The C/D ratio was equal to or over 0. 6 in 9 cases (16 eyes),and the values were inconsistent between both eyes in 55% of the patients. Treatment for glaucoma was immediate discontinuation of the steroids with antiglaucoma medication if necessary. Three eyes received filtering operations and 2 eyes had the removal of subconjunctival residual steroid. Normal IOP was restored in months up     

The Clinical Study of Healon 5 in Phacoemulsification and IOL Implantation

Purpose: To compare a new ophthalmic viscoelastic device (OVD) Healon 5 with two other kinds of OVDs commonly used in China during phacoemulsification and intraocular lens (IOL) implantation in terms of removal time, intraocular pressure, corneal and anterior chamber response.Methods: This prospective randomized study, in which patients and observers are masked, comprises niety eyes. They were randomly divided into 3 groups with different OVDs. Healon 5 (sodium hyaluronate 5 000 2.3%) was compared with Healon GV (sodium hyaluronate 7 000 1.4%) and Iviz (sodium hyaluronate 1.0%) . The surgeries were performed with temporal corneal incision, phacoemulsification in situ and foldable lens intracapsular implantation. The characteristic and the removal time of the viscoelastic material as well as the postoperative IOP, corneal reaction and anterior chamber reactions of the eyes were observed preoperatively and 24 hrs postoperatively. Exclusion criteria were glaucoma, a preoperative dilated pupil diameter small     

Progression rate to primary angle closure following laser peripheral iridotomy in primary angle-closure suspects: a randomised study

AIM: To report the progression rate (PR) to primary angle closure (PAC) following laser peripheral iridotomy (LPI) in PAC suspects (PACS). METHODS: Prospective, randomized controlled interventional clinical trial conducted at the Handan Eye Hospital, China. Totally 134 bilateral PACS, defined as non-visibility of the posterior trabecular meshwork for ≥180 degrees on gonioscopy were randomly assigned to undergo LPI in one eye. Gonioscopy and Goldmann applanation tonometry were performed prior to, on day 7 and 12mo post LPI. RESULTS: Eighty of 134 patients (59.7%) could be followed up at one year. The mean intraocular pressure (IOP) in treated eyes was 15.9±2.6 mm Hg at baseline, 15.4±3.0 mm Hg on day 7; 16.5±2.9 mm Hg at one month, and 15.5±2.9 mm Hg at 12mo; the IOP in untreated eyes was similar (P=0.834). One or more quadrants of the angle opened in 93.7% of the LPI treated eyes, but 67.0% (53/79) remained closed in two or more quadrants. The PR to PAC in untreated eyes was 3.75% and one developed acute angle-closure glaucoma (AACG); the PR to PAC in treated eyes was 2.5% and none had developed peripheral anterior synechia (PAS) or AACG. CONCLUSION: LPI can open some of the occludable angle in the majority of eyes with PACS, but 67% continue to have non-visibility of the trabecular meshwork for over 180 degrees.     

The Clinical Outcomes of Three Surgical Managements on Primary Angle-closure Glaucoma

Purpose: To investigate the efficacy of trabeculectomy, phacotrabeculectomy and phaco-emulsification in the management of primary angle closure glaucoma (PACG). Methods: A prospective observational study was performed in 88 chronic PACG patients (97 eyes) who were divided into three groups following defined indications to receive different surgical interventions. The indications and clinical outcomes were evaluated. The mean follow-up was (17.7±4.9) months. Results: Success rate in trabeculectomy, phacotrabeculectomy and phacoemulsification group was 81.08%, 78.57‰ and 81.25‰, respectively. The anterior chamber depth was deeper and the angle was wider postoperatively vs. preoperatively both in phaco-trabeculectomy and phacoemulsification group. No obvious changes were seen in trabeculectomy group. The coefficient of outflow facility of aqueous humor (C values) significantly increased in three groups postoperatively (P < 0.01). No severe intra-operative complications were found and the incidence of postoperative complications was low. Five eyes sustained hypotony 3±1.87 months in trabeculectomy group and 1 eye happened malignant glaucoma in phacotrabeculectomy group. The visual acuity in patients with phacotrabeculectomy plus intraocular lens implantation and those only with phacoemulsification plus intraocular lens implantation were improved 78.57% and 93.74%, respectively. No significant improvement was found in trabeculectomy group (χ2 = 47.10, P < 0.001). Conclusion: Three surgical interventions were beneficial to manage PACG and with co-existing cataract. The indication choosing was suggested according to visual acuity, angle closure circumference, cataract, medication requirements and optic nerve damage. Phacotrabeculectomy was recommended for angle closed ≥180° circumference while phacoemulsification for angle closed < 180°.     

CHRONIC ANGLE－CLOSURE GLAUCOMA MANAGEMENT BY RECONSTRUCTION OF THE ANTERIOR CHAMBER ANGLE

Aim: to estimate the efficacy of anterior chamber angle reconstruction with lens extraction and IOL implantation in chronic angle-closure glaucoma The results of treatment in 60 eyes of 52 patients (12 males and 40 females) are analyzed. Mean age of the patients was 63.7±3.7 years. Mean IOP before operation was 38 mm Hg (Mentor pneumatonograph Model 30), mean visual acuity 0.32. All the patients used hypotensive eyedrops, 18     

Ultrasound Biomicroscopic Dark Room Provocative Test

Purpose : To compare the clinical application value of Ultrasound biomicrsocpic dark room provocative test with the traditional dark room test in screening primary angle closure glaucoma (PACG).Methods: 22 eyes with PACG in prodromal stage and 30 eyes with deep anterior chamber and wide angle of 15 normal persons were observed in this trail. All 52 eyes were performed traditional dark room provocative test and ultrasound biomicorosopic darkroom test respectively. With different positive diagnostic criteria, the sensitivity of the two methods were compared using chi-squared analysis.Results : After staying in the dark room for 2 hours, In case group, IOP in 10 of 22 eyes rose more than 1. 07kPa(1kPa = 7.5mmHg), in 12 eyes less than 1.07kPa or had no changes; appositional angle closure were found by Goldmann gonioscopy in 8 eyes : 3 eyes in two quadrants, 5 eyes in more than two quadrants; the appositional angle closure was found by UBM in 15 eyes; 3 eyes in one quadrants, 5 eyes in two quadrants, 7 eyes     

THE LONG- TERM EFFECTIVENESS OF TRABECULECTOMY IN PRIMARY OPEN ANGLE GLAUCOMA AND IN PSEUDOEX- FOLIATIVE GLAUCOMA

Purpose: To investigate the effectiveness of trabeculectomy in patients with pseudoexfoliative glaucoma (PxG) and primary open angle glaucoma (POAG) within time. Patients: The study includes 76 eyes with POAG and 53 eyes with PXG, which underwent primary trabeculectomy and were followed-up at least 18 months. The eyes were evaluated in terms of reinstatement of     

Effect of low dose laser cycloplasty on deepening anterior chamber in chronic angle-closure glaucoma

AIM: To describe the outcome of using low-dose laser cycloplasty (LCP) in chronic angle-closure glaucoma (CACG). METHODS: A retrospective case series. Medical charts of CACG patients who underwent LCP in the Eye Hospital of Wenzhou Medical University were reviewed. The main outcomes included intraocular pressure (IOP), the number of glaucoma medication, anterior segment parameters and surgery-related complications. RESULTS: A total of 7 eyes of 7 CACG patients (age 38.9±11.0y) underwent LCP with a mean follow-up of 27.1±13.7mo (range 16–48mo). Following LCP, mean IOP and glaucoma medications decreased from 26.1±6.1 mm Hg with 3.1±1.1 glaucoma medications pre-treatment to 14.9±3.1 mm Hg (P=0.027) with 0.4±1.1 glaucoma medications (P=0.001) at final follow-up. The anterior chamber depth (ACD), angle opening distance500 and trabecular-iris angle increased from 1.65±0.33 mm, 0.05 mm (range 0–0.30 mm) and 5.1° (range, 0–31.97°) at baseline to 1.98±0.43 mm (P=0.073), 0.53 mm (range 0.42–0.91 mm, P=0.015), 45.9° (range, 40.2°–59.4°, (P=0.015) in the long-term follow-up, respectively. The deepening of ACD and reopening of anterior chamber angle (ACA) was observed in 6 eyes (85.7%). CONCLUSION: LCP is a promising treatment option for patients with CACG via reducing IOP and glaucoma medication without serious complications. In addition, LCP can bring a significant deepening in ACD and reopening of ACA.     

Analysis of 24-hour Monitoring of Intraocular Pressure in 1055 Eyes

Purpose：To investigate the clinical significance of 24-hour monitoring of intraocular pressure （IOP）.Methods：A total of 571 cases （1055 eyes） undergoing 24-hour monitoring of IOP in the Second People＇s Hospital of Zhengzhou between June 2012 and March 2013 were retrospectively analyzed.Results：Among all 1055 eyes,298 had suspected glaucoma （28.2％）; 390 （37.0％） were diagnosed with glaucoma but received no treatment （312 with primary open angle glaucoma （POAG） and 78 with primary angle closure glaucoma （PACG）） ;215（20.4％） were diagnosed with glaucoma and received medical treatment ; 132 （12.5 ％） underwent glaucoma filtration surgery; and there were 20 others.Through 24-hour IOP monitoring,104 among 298 cases with suspected glaucoma were diagnosed with normal tension glaucoma （NTG）,110 with POAG,and 28 with the secondary glaucoma.Condition assessment and treatment plans were presented for 390 glaucoma cases receiving no treatment.Adjustment was made in the medical treatment of 138 eyes.Following glaucoma filtration surgery,52 eyes received clinical advice on subsequent treatment.Conclusion：The simplified 24-hour IOP monitoring method is readily accepted by patients,which is of great significance for providing guidance on the diagnosis of glaucoma and the assessment of the efficacy of glaucoma surgery.However,one-time 24-hour IOP monitoring is not sufficiently efficacious to make a definite diagnosis of NTG.Therefore,long-term follow-up and repeated 24-hour IOP monitoring are required to diagnose NTG,along with a variety of related examinations.     

Therapeutic effect analysis on the treatment of congenital glaucoma through modified combined trabeculotomy-trabeculectomy

AIM: To evaluate the therapeutic effect and the safety of the treatment of congenital glaucoma through modified combined trabeculotomy-trabeculectomy. METHODS: The clinical data of 27 cases (altogether 42 eyes), which included 7 cases of infants (10 eyes) and 20 cases of teenagers (32 eyes), of congenital glaucoma undertook modified combined trabeculotomy-trabeculectomy were analyzed retrospectively. The parameters evaluated included the post operation visual acuity, the anterior chamber, the filtering bleb, the intraocular pressure, the C/D ratio, visual field, the retinal nerve fiber layer changes and the complications. RESULTS: The follow-up period was 1 to 29mo, averaging 13.3±7.7mo. Upon the last visit after the operation, functional filtering blebs developed in all the involved eyes. The intraocular pressure was controlled under 21 mm Hg, which was decreased by 60% when compared with that before the operation, without using any medication. There were no significant changes in the post operation visual acuity and the retinal nerve fiber layer thickness before and after the operation in teenager group (P＞0.05), and both the post operation C/D ratio and the visual field mean defect (MD) were reduced compared with those before the operation (P<0.05). There were no severe complications in any of the patients. CONCLUSION: The modified combined trabeculotomy-trabeculectomy can effectively reduce the intraocular pressure and control the development of glaucoma in cases of congenital glaucoma. It is a safe and effective operative method for the treatment of congenital glaucoma.     

Assessment of iris volume in glaucoma patients with type 2 diabetes mellitus by AS-OCT

AIM: To examine the change of iris volume measured by CASIA2 anterior segment optical coherence tomography (AS-OCT) in glaucoma patients with or without type 2 diabetes mellitus (T2DM) and explore if there is a correlation between hemoglobin A1c (HbA1c) level and iris volume. METHODS: In a cross-sectional study, 72 patients (115 eyes) were divided into two groups: primary open angle glaucoma (POAG) group (55 eyes) and primary angle-closure glaucoma (PACG) group (60 eyes). Patients in each group were separately classified into patients with or without T2DM. Iris volume and glycosylated HbA1c level were measured and analyzed. RESULTS: In the PACG group, diabetic patients’ iris volume was significantly lower than those of non-diabetics (P=0.02), and there was a significant correlation between iris volume and HbA1c level in the PACG group (r=-0.26, P=0.04). However, diabetic POAG patients’ iris volume was noticeably higher than those of non-diabetics (P=0.01), and there was a significant correlation between HbA1c level and iris volume (r=0.32, P=0.02). CONCLUSION: Diabetes mellitus impact iris volume size, as seen by increased iris volume in the POAG group and decreased iris volume in the PACG group. In addition, iris volume is significantly correlated with HbA1c level in glaucoma patients. These findings imply that T2DM may compromise iris ultrastructure in glaucoma patients.     

Evaluation of a new nomogram for Ferrara ring segment implantation in keratoconus

AIM: To evaluate the short-term clinical outcomes of Ferrara rings in keratoconus using an optimized nomogram developed after several years of research and retrospective analysis of clinical data. METHODS: This prospective longitudinal non-comparative clinical trial evaluated 88 eyes of 88 patients (age 18-62y) with keratoconus diagnosis from two Spanish centers. Ferrara ring segment (AJL Ophthalmic) implantation was performed in all cases, using the mechanical procedure in 25 eyes (28.4%) and a femtosecond laser-assisted procedure in 63 eyes (71.6%). The ring segments implanted in each case were selected using a new optimized nomogram that considered variables such as anterior corneal asphericity and astigmatism or the discrepancy among astigmatism and coma orientations. Visual, refractive, corneal topographic, aberrometric, and pachymetric changes after surgery were evaluated during a 3-month follow-up. RESULTS: The implants induced a significant refractive change as well as an improvement in uncorrected (UDVA) and corrected distance visual acuity (CDVA; P<0.001). Postoperative CDVA of 0.10 logMAR or better was achieved in 28.4% and 46.5% of eyes, respectively. Two eyes (2.3%) lost two or more lines of CDVA whereas a total of 53.5% of eyes gained lines of CDVA. A significant central anterior and posterior corneal flattening was induced (P≤0.003), with a significant reduction of anterior (P<0.001) and posterior corneal astigmatisms (P=0.048), and a change in anterior asphericity (P<0.001). Total primary coma (6 mm pupil) change was also statistically significant (preoperative 3.66±3.04 µm vs postoperative 2.33±2.26 µm, P<0.001). No significant differences were found in the effect of ring segments between cases implanted using the mechanical and femtosecond techniques (P≥0.101). CONCLUSION: The implantation of Ferrara rings based on the nomogram evaluated is safe and effective for promoting a visual rehabilitation in keratoconus, with a relevant control of primary coma aberration.