Posterior Corneal Asphericity and the Refractive Outcome after Combined Phacovitrectomy.

BACKGROUND: We assessed the correlation of posterior corneal asphericity and the refractive prediction error of the SRK-T and Barrett II Universal formulas for eyes following phacovitrectomy with peeling of the internal limiting membrane (ILM). PATIENTS AND METHODS: We retrospectively analyzed 41 eyes of 41 patients following a combined phacovitrectomy with ILM peeling. Surgeries were performed by one fellowship-trained vitreoretinal surgeon between 2016 and 2021. RESULTS: Of the 41 patients, 41 eyes were included, with all having at least 1 month of postoperative data. Of the 41 eyes, 19 eyes were female (46%) and 22 were male (54%). The average age of the study population was 77.5 ± 10.7 years. The mean axial length (AL) was 22.7 ± 4.6 mm and the mean anterior chamber depth (ACD) was 3 ± 0.8 mm. The mean posterior Q value was - 0.29 ± 0.27. The mean absolute error (MAE) values 1-month postoperatively for the SRK-T and Barrett II Universal formulas were 0.73 and 0.65, respectively. Regression analysis yielded a significant correlation between posterior corneal asphericity and SRK-T MAE (r = 0.35, R2 = 0.12, p < 0.05) only. CONCLUSIONS: Posterior corneal surface asphericity is correlated to the refractive error of the SRK-T formula for eyes following phacovitrectomy.

Influence of Posterior Corneal Asphericity on Refractive Error of SRK-T and Barrett Formulas for Lucidis IOL.

PURPOSE: To evaluate the influence of posterior corneal asphericity on the refractive error using SRK-T and Barrett formulas for the intraocular lens (IOL) power calculation for Lucidis Extended Depth of Focus (EDOF) IOL. SETTING: This study was carried out at a tertiary ophthalmology center in Geneva, Switzerland. DESIGN: A retrospective study. Medical records from all enrolled patients were analyzed and the following information was extracted retrospectively, over 1 month following surgery. METHODS: We retrospectively reviewed 75 eyes that underwent cataract surgery and were implanted with a Lucidis EDOF IOL. We measured the posterior corneal asphericity (Q value), axial length (AL), and anterior chamber depth (ACD) and then calculated the IOL power using SRK-T and Barrett formulas. RESULTS: Seventy-five eyes were included, all of which had 1-month postoperative data. In the cohort, 32 eyes were from females (43%) and 43 from males (57%). The mean age of the study population was 73 ± 8.8 years. The mean AL was 23.5 ± 0.98 and the mean ACD was 3.13 ± 0.3. The mean posterior Q value was - 0.35 ± 0.2. In a regression analysis, we found a statistically significant relationship between the error in refraction prediction and the posterior Q value, irrespective of the formula used. The relationship between posterior corneal asphericity and the refraction prediction error was stronger for the Barrett II Universal formula than for the SRK-T formula. CONCLUSIONS: Posterior corneal asphericity was correlated with the refractive error of calculation of both SRK-T and Barrett formulas, with a stronger correlation to the latter formula.

Visual Outcomes after Implantation of Lucidis EDOF IOL.

Purpose: To evaluate the visual performance and clinical outcomes after implantation of Lucidis EDOF IOL following cataract surgery. Design: In this retrospective study, medical records from all enrolled patients were analyzed, and the following information was extracted retrospectively over 3 months following surgery. Materials and Methods: We reviewed retrospectively 181 eyes of 98 patients, who underwent cataract surgery with Lucidis extended depth of focus IOL. Results: 44 patients were males (45%) and 54 were females (55%). The average age of the study population was 68 ± 11 years. The mean preoperative BCVA (logMAR) was 0.19 ± 0.18. The mean root mean square (RMS) high order aberration (HOA) was 0.18 ± 0.1. Monocular BCVA results were 0.02 ± 0.04 (logMAR) and 0.028 ± 0.04 (logMAR) 1 month and 3 months postoperatively, respectively. Between the baseline and 1-month measures, monocular distance BCVA improved by an average of 0.17 ± 0.14 logMAR (p = 0.0001). Between the baseline and 3-month postoperative measures, monocular distance BCVA improved by an average of 0.16 ± 0.13 logMAR (p = 0.0001). Monocular UDVA 1 and 3 months postoperatively was 0.08 ± 0.1 logMAR and 0.067 ± 0.08 logMAR, respectively. 1-Month postoperative binocular UDVA was 0.036 ± 0.05 logMAR, binocular UIVA was 0.1 ± 0.08 logMAR, and binocular UNVA was 0.12 ± 0.14 logMAR. 3-Month postoperative binocular UDVA was 0.038 ± 0.05 logMAR, binocular UIVA was 0.09 ± 0.1 logMAR, and binocular UNVA was 0.16 ± 0.14 logMAR. Conclusions: Lucidis EDOF IOL achieves good visual performances in all distances.

Influence of Posterior Corneal Asphericity On Power Calculation Error After Laser In Situ Keratomileusis or Photorefractive Keratectomy for Myopia.

OBJECTIVES: To assess the impact of posterior corneal asphericity on postoperative calculation error using the Haigis-L and the Barrett formulas for eyes after laser in situ keratomileusis or photorefractive keratectomy (PRK). METHODS: We assessed the mean absolute error (MAE) of two power calculation formulas, Barrett true-K and Haigis-L formulas, in a retrospective analysis of 34 eyes of 34 patients who underwent cataract surgery. We performed a regression analysis between corneal parameters (anterior and posterior Q values, Kmax, K1, and K2) and the MAE of each formula. RESULTS: In the cohort, 11 eyes were of women and 23 of men. The average age of the study population was 66.5±8.6 years. The mean axial length was 24±4.7 mm, the mean anterior chamber depth was 3.27±0.7 mm, and the mean posterior Q-value was -0.15±0.28. The MAE of Haigis-L and Barrett true-K formulas were 0.72 and 0.68, respectively (P=0.54). The regression analysis showed a statistically significant relationship only between the error in refraction prediction and the posterior Q-value regardless of the formula used. The coefficient of determination was higher for the Barrett true-K formula (r=0.52; R2=0.28; P<0.05), compared with the Haigis-L (r=0.49; R2=0.25; P<0.05). CONCLUSIONS: Posterior corneal surface asphericity influences the refractive error of calculation using both Haigis-L and Barrett true-K formulas for eyes after a myopic PRK or laser-assisted in situ keratomileusis surgery.

Posterior Corneal Asphericity Effect on Postoperative Astigmatism after EDOF Intraocular Lens Implantation in Cataract Patients.

AIM: To assess the impact of posterior corneal asphericity on postoperative astigmatism. METHODS: We included retrospectively 70 eyes of 70 patients that underwent cataract surgery. We included data of the Q value, K max, K1, K2, astigmatism AL, and ACD. We performed a vectorial analysis to calculate the astigmatic vectors. RESULTS: Seventy eyes were evaluated. 40 eyes were of females (58%) and 30 of males (42%). The average cohort age was 73 ± 8.9 years. Axial length (AL) was 23.5 ± 0.9, anterior chamber depth (ACD) was 3.13 ± 0.3, and the average posterior Q value was -0.35 ± 0.2. The only significant predictive variable for the correction index (CI) was the posterior Q value (r = 0.24, p < 0.05) and for the surgically induced astigmatism (SIA) (ß = 0.34, r = 0.58, p < 0.05). CONCLUSION: Posterior corneal surface asphericity significantly influences the surgically induced astigmatism and the overcorrection for cataract patients after Lucidis EDOF IOL implantation.

Retinal venous pressure measurements in patients with Flammer syndrome and metabolic syndrome.

BACKGROUND: The purpose of this research is to analyze retinal venous pressure (RVP) of both eyes of patients who visited a Swiss ophthalmic practice and compare values among the following groups of patients with primary open-angle glaucoma (POAG), Flammer syndrome (FS), and metabolic syndrome (MetS). METHODS: RVP was measured in both eyes of all patients who visited a Swiss ophthalmic practice during March 2016 till November 2016, and the results were analyzed retrospectively. All measurements were performed by one physician by means of ophthalmodynamometry. Ophthalmodynamometry is done by applying an increasing pressure on the eye via a contact lens. The minimum force required to induce a venous pulsation is called ophthalmodynamometric force (ODF). The RVP is defined and calculated as the sum of ODF and intraocular pressure (IOP) [RVP = ODF + IOP]. RESULTS: Spontaneous central retinal venous pulsation was present in the majority of the patients (192 out of 357, 53.8%). Spontaneous RVP rate was significantly negatively correlated with age (r = -0.348, p < 0.001). A significantly increased RVP was noted in FS, MetS, and POAG patients, particularly those POAG patients who also suffered from FS (p < 0.005). CONCLUSIONS: Although most patients had a spontaneous RVP, those with FS, POAG, and MetS had increased RVP. Measuring RVP by means of ophthalmodynamometry provides predictive information about certain ocular diseases and aids in instituting adequate preventive measures.

Nutritional recommendations for individuals with Flammer syndrome.

The Flammer syndrome (FS) describes the phenotype of people with a predisposition for an altered reaction of the blood vessels to stimuli like coldness or emotional stress. The question whether such people should be treated is often discussed. On the one hand, most of these subjects are healthy; on the other hand, FS seems to predispose to certain eye diseases such as normal tension glaucoma or retinitis pigmentosa or systemic diseases such as multiple sclerosis or tinnitus. A compromise between doing nothing and a drug treatment is the adaption of nutrition. But what do we mean by healthy food consumption for subjects with FS? The adaption of nutrition depends on the health condition. Whereas patients with e.g. a metabolic syndrome should reduce their calorie intake, this can be counterproductive for subjects with FS, as most subjects with FS have already a low body mass index (BMI) and the lower the BMI the stronger the FS symptoms. Accordingly, while fasting is healthy e.g. for subjects with metabolic syndrome, fasting can even dangerously aggravate the vascular dysregulation, as it has been nicely demonstrated by the loss of retinal vascular regulation during fasting. To give another example, while reducing salt intake is recommended for subjects with systemic hypertensions, such a salt restriction can aggravate systemic hypotension and thereby indirectly also the vascular regulation in subjects with FS. This clearly demonstrates that such a preventive adaption of nutrition needs to be personalized.

Study of corneal copper deposits in Wilson's disease by in vivo confocal microscopy.

PURPOSE: To study corneal copper deposits in Wilson's disease (WD) patients by traditional biomicroscopy and in vivo laser scanning confocal microscopy (LSCM). METHODS: Twenty WD patients and 20 matched controls underwent an ophthalmic examination in one eye randomly chosen, including slit lamp biomicroscopy with Goldmann's three-mirror contact lens examination and LSCM, in order to evaluate copper deposits in the peripheral cornea. RESULTS: No control subjects had corneal changes at both traditional biomicroscopy and LSCM. Only 25% of WD patients had detectable slit lamp changes, compared with 75% with LSCM examination. All cases detected by slit lamp were detected by LSCM. A significant correlation (p < 0.01) was found between deposit intensity at LSCM and daily urinary copper excretion. CONCLUSION: LSCM could detect copper deposition in WD corneas in more patients than traditional examination; it may therefore provide important information in cases of suspected WD diagnosis.

Management of corneal ectasia and cataract following photorefractive keratectomy.

A 42-year-old man was referred to our clinic 18 months after bilateral photorefractive keratectomy (PRK). He had been on topical prednisolone acetate for 12 months because of post-PRK grade 4 haze. On his first visit, visual acuity was limited to light perception in both eyes because of moderate haze, significant corneal ectasia, and a white cataract. A 2-step surgical approach was elected in both eyes. First, a deep anterior lamellar keratoplasty was performed. Six weeks later, phacoemulsification with intraocular lens implantation was performed. Compared with a triple procedure combining penetrating keratoplasty and cataract surgery in 1 stage, the 2-step approach may lower the risk for corneal graft rejection and reduce ametropia.