Using an excel spreadsheet to convert Snellen visual acuity to LogMAR visual acuity—further explanation

Background/aimsTo evaluate the time needed for patients with Boston type 1 keratoprosthesis (KPro) to reach their best-corrected visual acuity (BCVA) and all contributing factors.MethodsWe retrospectively reviewed 137 consecutive eyes from 118 patients, measured how long they needed to reach their BCVA and looked at factors that might affect this time duration including patient demographics, ocular comorbidities and postoperative complications.ResultsThe mean follow-up was 5.49 years. The median time to BCVA postoperatively was 6 months, with 47% of patients achieving their BCVA by 3 months. The mean best achieved logMAR visual acuity was 0.71, representing a gain of 6 lines on the Snellen visual acuity chart. Postoperative glaucoma, retroprosthetic membrane (RPM) and endophthalmitis prolonged this duration. We found no correlation between the following factors and time to BCVA: gender, age, indication for KPro surgery, primary versus secondary KPro, number of previous penetrating keratoplasties, previous retinal surgery, intraoperative anterior vitrectomy and preoperative glaucoma.ConclusionIn our retrospective cohort, the majority of subjects reached their BCVA between 3 and 6 months after KPro implantation. This duration was significantly prolonged by the development of postoperative glaucoma, RPM and endophthalmitis.

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Estimating visual acuity by character counting using the Snellen visual acuity chart

Eye ◽

10.1038/sj.eye.6701583 ◽

2004 ◽

Vol 19 (6) ◽

pp. 622-624 ◽

Cited By ~ 5

Author(s):

A H Levy ◽

T J McCulley ◽

B L Lam ◽

W J Feuer

Keyword(s):

Visual Acuity ◽

Snellen Visual Acuity

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Inverted Internal Limiting Membrane Flap Technique for Extra Large Macular Holes

Current Trends in Ophthalmology ◽

10.18314/ctoy.v1i1.371 ◽

2018 ◽

Vol 1 (1) ◽

pp. 07-13

Author(s):

Ogugua Ndubuisi Okonkwo ◽

Adekunle Olubola Hassan ◽

Olufemi Oderinlo

Keyword(s):

Visual Acuity ◽

Case Series ◽

Functional Results ◽

Internal Limiting Membrane ◽

Vital Role ◽

Symptom Duration ◽

Flap Technique ◽

Macular Holes ◽

Snellen Visual Acuity ◽

Sd Oct

Aim: To investigate the outcome of the inverted Internal Limiting Membrane (ILM) flap technique for extra large idiopathic macular holes (MHs).Methods: A retrospective non-comparative surgical case series of seven eyes of 7 patients with MHs (base diameter of at least 1000 ?m) was conducted. All the MHs were treated using pars plana vitrectomy and brilliant blue G (BBG)-assisted inverted ILM flap technique. Spectral Domain- Optical Coherence Tomography (SD-OCT) images were used to assess the anatomical outcomes of surgery including the macular microstructure, while Best Corrected Snellen Visual Acuity (BCSVA) was used to evaluate the functional outcomes.Results: The average MH size was 1241microns and average symptom duration was nineteen months. All eyes achieved successful anatomical closure and there was no occurrence of a flat open type closure. SD-OCT microstructural study revealed a reconstruction of the Ellispod Zone (EZ) and External Limiting Membrane (ELM), in only 3 eyes. There was an improvement in visual acuity in 5 eyes, while 2 eyes maintained the same as pre operative vision. The largest increase in post operative visual acuity gain was a 4-line improvement in Best Corrected Snellen Visual Acuity (BCSVA) noted in one of the 3 eyes with reconstructed EZ and ELM. The 3 months symptom duration in this patient was the shortest in this series.Conclusion: Inverted ILM flap technique is a safe and effective approach for the management of extra large chronic idiopathic MHs with demonstrably good anatomical and limited functional results in a majority of cases. Postoperative reconstruction of the microstructure is however seen only in a minority of eyes. Despite an absence of the outer retina (EZ and ELM), some eyes still experience an improvement in vision. The symptom duration may play a vital role in functional outcome in this subset of extra large chronic MHs.

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The relationship between indoor and outdoor Snellen visual acuity in cataract patients

Journal of Cataract & Refractive Surgery ◽

10.1016/s0886-3350(88)80061-0 ◽

1988 ◽

Vol 14 (1) ◽

pp. 35-39 ◽

Cited By ~ 11

Author(s):

Albert C. Neumann ◽

George R. McCarty ◽

Thomas O. Steedle ◽

Donald R. Sanders ◽

Marsha G. Raanan

Keyword(s):

Visual Acuity ◽

Snellen Visual Acuity ◽

The Relationship ◽

Cataract Patients ◽

Indoor And Outdoor

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Contrast Sensitivity and Visual-Field Thresholds in Patients with Thyroid Optic Neuropathy

Perception ◽

10.1068/v970237 ◽

1997 ◽

Vol 26 (1_suppl) ◽

pp. 194-194

Author(s):

J Jankauskiene ◽

R Lukauskiene ◽

B Mickiene

Keyword(s):

Visual Acuity ◽

Visual Field ◽

Contrast Sensitivity ◽

Optic Neuropathy ◽

Control Group ◽

Ophthalmological Examination ◽

Threshold Test ◽

Spatial Frequencies ◽

Snellen Visual Acuity ◽

The Mean

Thyroid optic neuropathy is one of the most troubling complications of endocrine ophthalmopathies. It is related to the degree of extraocular muscle swelling in the apex of the orbit. The purpose of this study was to investigate contrast sensitivity and visual-field thresholds in patients with thyroid optic neuropathy. We examined twenty-two patients aged 29 – 63 years (mean 45.3 years). The control group consisted of fifteen healthy persons of similar age. Contrast sensitivity was measured by means of Volkov's charts (sinusoidal gratings) at eight spatial frequencies from 17.5 to 0.46 cycles deg−1. The visual field was investigated with a static automatic perimeter (Allgan Humphrey Field Analyzer) by means of the central 30-2 threshold test. All patients underwent a complete ophthalmological examination including best corrected Snellen visual acuity, fundus copy, and proptosis measurement with the Hertel exophthalmometer. The mean proptosis of patients was 19.4 mm. Fifteen of the patients had decreased visual acuity. Contrast sensitivity at low spatial frequencies was significantly reduced in the patients. It was established that a reduction of visual-field threshold accompanies the decrease of visual acuity. Our results show that contrast sensitivity and visual-field threshold testing are very sensitive at detecting early optic neuropathy and may be a useful means of following patients after treatment.

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Self-retained cryopreserved amniotic membrane for treating severe corneal ulcers: a comparative, retrospective control study

Scientific Reports ◽

10.1038/s41598-020-73672-2 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Han Y. Yin ◽

Anny M. S. Cheng ◽

Sean Tighe ◽

Philip Kurochkin ◽

Jamie Nord ◽

...

Keyword(s):

Visual Acuity ◽

Adjuvant Therapy ◽

Corneal Ulcer ◽

Control Group ◽

Retrospective Case ◽

Corneal Ulcers ◽

Initial Visual Acuity ◽

Snellen Visual Acuity ◽

Clinically Significant ◽

Control Study

Abstract To compare the effectiveness of self- retained cryopreserved AM as an adjuvant therapy for infectious corneal ulcers. Retrospective, case–control study of 24 eyes of 24 consecutive patients with central and paracentral corneal infectious ulcers and initial visual acuity worse than 20/200. Among them, 11 eyes of 11 patients received additional placement of self-retained cryopreserved AM. Epithelialization and Best Corrected Snellen Visual Acuity (BCSVA) were compared between the two groups. At baseline, both groups had comparable age, gender, visual acuity (VA), size and location of corneal ulcer. Patients receiving additional placement of cryopreserved AM had significantly faster epithelialization within 3.56 ± 1.78 weeks vs 5.87 ± 2.20 weeks (p = 0.01) and achieved complete epithelialization in significantly more patients (72.7% vs 23.1% p = 0.04) despite overall larger baseline defect size (32.7 ± 19.5 mm2 vs 21.5 ± 10.7 mm2, p = 0.11). Consequently, the AM group had clinically significant BCSVA (> 3 lines) (81.8% vs 38.4%, p = 0.047) and total VA improvement (log MAR 0.7 ± 0.6 vs 1.6 ± 0.9, p = 0.016) compared to the control group at the time of complete epithelialization. In-office sutureless AM may be an effective adjuvant therapy in treating sight-threatening infectious corneal ulcers by promoting faster corneal epithelialization and overall better recovery of the VA.

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