• Estimation of effective lens position using a method independent of preoperative keratometry readings.

      Dooley, Ian; Charalampidou, Sofia; Nolan, John; Loughman, James; Molloy, Laura; Beatty, Stephen; Department of Ophthalmology, Waterford Regional Hospital, Institute of Eye, Surgery, Dublin, Ireland. iandooley@eustace.net (2012-02-01)
      PURPOSE: To evaluate the validity of a keratometry (K)-independent method of estimating effective lens position (ELP) before phacoemulsification cataract surgery. SETTING: Institute of Eye Surgery, Whitfield Clinic, Waterford, Ireland. DESIGN: Evaluation of diagnostic test or technology. METHODS: The anterior chamber diameter and corneal height in eyes scheduled for cataract surgery were measured with a rotating Scheimpflug camera. Corneal height and anterior chamber diameter were used to estimate the ELP in a K-independent method (using the SRK/T [ELP(rs)] and Holladay 1 [ELP(rh)] formulas). RESULTS: The mean ELP was calculated using the traditional (mean ELP(s) 5.59 mm +/- 0.52 mm [SD]; mean ELP(h) 5.63 +/- 0.42 mm) and K-independent (mean ELP(rs) 5.55 +/- 0.42 mm; mean ELP(rh) +/- SD 5.60 +/- 0.36 mm) methods. Agreement between ELP(s) and ELP(rs) and between ELP(h) and ELP(rh) were represented by Bland-Altman plots, with mean differences (+/- 1.96 SD) of 0.06 +/- 0.65 mm (range -0.59 to +0.71 mm; P=.08) in association with ELP(rs) and -0.04 +/- 0.39 mm (range -0.43 to +0.35 mm; P=.08) in association with ELP(rh). The mean absolute error for ELP(s) versus ELP(rs) estimation and for ELP(h) versus ELP(rh) estimation was 0.242 +/- 0.222 mm (range 0.001 to 1.272 mm) and 0.152 +/- 0.137 mm (range 0.001 to 0.814 mm), respectively. CONCLUSION: This study confirms that the K-independent ELP estimation method is comparable to traditional K-dependent methods and may be useful in post-refractive surgery patients.
    • Estimation of effective lens position using a method independent of preoperative keratometry readings.

      Dooley, Ian; Charalampidou, Sofia; Nolan, John; Loughman, James; Molloy, Laura; Beatty, Stephen; Department of Ophthalmology, Waterford Regional Hospital, Institute of Eye Surgery, Dublin, Ireland. iandooley@eustace.net (2011-03)
      To evaluate the validity of a keratometry (K)-independent method of estimating effective lens position (ELP) before phacoemulsification cataract surgery.
    • Ocular injury requiring hospitalisation in the south east of Ireland: 2001-2007.

      Saeed, Ayman; Khan, Irfan; Dunne, Orla; Stack, Jim; Beatty, Stephen; Waterford Regional Hospital, Waterford, Ireland. aymantalat@gmail.com (2012-02-01)
      AIM: To investigate whether recent socio-demographic changes and recent health and safety measures have impacted on the trends of ocular trauma in the South East of Ireland. METHODS: We retrospectively reviewed all cases of ocular trauma admitted to our department between October 2001 and September 2007, and the following data were retrieved: demographic details; mechanism of injury and nature of injury. RESULTS: During the study period, 517 patients were admitted with ocular trauma. Work-related and home-related activities were the commonest causes of admission, and accounted for 160 (31.8%) and 145 (28.4%) cases, respectively. In 2006/2007, and following the influx of migrant workers from the 10 new EU accession states (EUAS), the incidence of hospitalised ocular injuries per 100,000 was 89 in persons from the EUAS versus 18 in those of Irish origin, P < or = 0.0001. After adding the offence of not wearing a seat belt to the traffic penalty point system in Ireland, the proportion of road traffic accident (RTA)-related ocular injuries dropped significantly from 6.7% to 2.4%, P=0.03. CONCLUSION: The inclusion of the offence of not wearing a seat belt in the traffic penalty point system may have contributed to the significantly lower proportion of hospitalised ocular injuries attributable to RTAs. Also, the demographic profile of patients admitted because of ocular trauma has changed over the last 6 years, reflected in an increasing proportion of these injuries in persons from the EUAS. These data will inform healthcare providers, and those involved in developing health and safety guidelines for the workplace.
    • Psychophysical function in age-related maculopathy.

      Neelam, Kumari; Nolan, John; Chakravarthy, Usha; Beatty, Stephen; Waterford Institute of Technology, Waterford Regional Hospital, Waterford,, Republic of Ireland. Kumari.neelam@Alexhosp.com.sg (2012-02-01)
      Age-related macular degeneration (AMD), the late stage of age-related maculopathy (ARM), is the leading cause of blind registration in developed countries. The visual loss in AMD occurs due to dysfunction and death of photoreceptors (rods and cones) secondary to an atrophic or a neovascular event. The psychophysical tests of vision, which depend on the functional status of the photoreceptors, may detect subtle alterations in the macula before morphological fundus changes are apparent ophthalmoscopically, and before traditional measures of visual acuity exhibit deterioration, and may be a useful tool for assessing and monitoring patients with ARM. Furthermore, worsening of these visual functions over time may reflect disease progression, and some of these, alone or in combination with other parameters, may act as a prognostic indicator for identifying eyes at risk for developing neovascular AMD. Lastly, psychophysical tests often correlate with subjective and relatively undefined symptoms in patients with early ARM, and may reflect limitation of daily activities for ARM patients. However, clinical studies investigating psychophysical function have largely been cross-sectional in nature, with small sample sizes, and lack consistency in terms of the grading and classification of ARM. This article aims to comprehensively review the literature germane to psychophysical tests in ARM, and to furnish the reader with an insight into this complex area of research.
    • Risk factors for age-related maculopathy.

      Connell, Paul P; Keane, Pearse A; O'Neill, Evelyn C; Altaie, Rasha W; Loane, Edward; Neelam, Kumari; Nolan, John M; Beatty, Stephen; Waterford Regional Hospital, Dunmore Road, Waterford, Ireland. (2012-02-01)
      Age-related maculopathy (ARM) is the leading cause of blindness in the elderly. Although beneficial therapeutic strategies have recently begun to emerge, much remains unclear regarding the etiopathogenesis of this disorder. Epidemiologic studies have enhanced our understanding of ARM, but the data, often conflicting, has led to difficulties with drawing firm conclusions with respect to risk for this condition. As a consequence, we saw a need to assimilate the published findings with respect to risk factors for ARM, through a review of the literature appraising results from published cross-sectional studies, prospective cohort studies, case series, and case control studies investigating risk for this condition. Our review shows that, to date, and across a spectrum of epidemiologic study designs, only age, cigarette smoking, and family history of ARM have been consistently demonstrated to represent risk for this condition. In addition, genetic studies have recently implicated many genes in the pathogenesis of age-related maculopathy, including Complement Factor H, PLEKHA 1, and LOC387715/HTRA1, demonstrating that environmental and genetic factors are important for the development of ARM suggesting that gene-environment interaction plays an important role in the pathogenesis of this condition.
    • Risk factors, microbiological findings, and clinical outcomes in cases of microbial keratitis admitted to a tertiary referral center in ireland.

      Saeed, Ayman; D'Arcy, Fiona; Stack, Jim; Collum, Louis M; Power, William; Beatty, Stephen; Waterford Regional Hospital, Waterford, Ireland. aymantalat@gmail.com (2012-02-01)
      AIM: To identify the risk factors for, and to report the microbiological findings and clinical outcomes of, severe microbial keratitis (MK). METHODS: This was a retrospective study of all cases of presumed MK admitted to a tertiary referral center over a 2-year period (September 2001 to August 2003). Data recorded included demographic data, details relating to possible risk factors, results of microbiological studies, clinical findings at presentation, and clinical and visual outcomes. RESULTS: Ninety patients were admitted with a diagnosis of presumed MK during the study period. The mean age of patients was 45 +/- 32 years, and the male to female ratio was 47:43 (52.2%:47.7%). Predisposing risk factors for MK included contact lens wear (37; 41.1%), anterior segment disease (19; 21.1%), ocular trauma (13; 14.4%), systemic disease (5; 5.6%), and previous ocular surgery (1; 1.1%). Cultured organisms included gram-negative bacteria (17; 51.5%), gram-positive bacteria (11, 33.3%), acanthamoeba (2; 6.1%), and fungi (1; 3%). Visual acuity improved significantly after treatment [mean best-corrected visual acuity (+/-standard deviation) at presentation: 0.76 (+/-0.11); mean best-corrected visual acuity at last follow-up: 0.24 (+/-0.07); P < 0.001]. Secondary surgical procedures were required in 18 (20%) cases, and these included punctal cautery (1; 1.1%), tissue glue repair of corneal perforation (2; 2.2%), tarsorrhaphy (9; 9.9%), Botulinum toxin-induced ptosis (1; 1.1%), penetrating keratoplasty (3; 3.3%), and evisceration (2; 2.2%). CONCLUSIONS: Contact lens wear remains a significant risk factor for severe MK. MK remains a threat to vision and to the eye, but the majority of cases respond to prompt and appropriate antimicrobial therapy.
    • Surgically induced astigmatism after phacoemulsification with and without correction for posture-related ocular cyclotorsion: randomized controlled study.

      Dooley, Ian; Charalampidou, Sofia; Malik, Arhsed; Ormonde, Greta; Loughman, James; Molloy, Laura; Beatty, Stephen; Department of Ophthalmology, Waterford Regional Hospital, the Institute of Eye, Surgery, Whitfield Clinic, Suite 14, Whitfield Clinic, Cork Road, Waterford,, Ireland. iandooley@eustace.net (2012-02-01)
      PURPOSE: To report the impact of posture-related ocular cyclotorsion on one surgeon's surgically induced astigmatism (SIA) results and the variance in SIA. SETTING: Institute of Eye Surgery, Whitfield Clinic, Waterford, Ireland. METHODS: This prospective randomized controlled study included eyes that had phacoemulsification with intraocular lens implantation. Eyes were randomly assigned to have (intervention group) or not have (control group) correction for posture-related ocular cyclotorsion. In the intervention group, the clear corneal incision was placed precisely at the 120-degree meridian with instruments designed to correct posture-related ocular cyclotorsion. In the control group, the surgeon endeavored to place the incision at the 120-degree meridian, but without markings. RESULTS: The intervention group comprised 41 eyes and the control group, 61 eyes. The mean absolute SIA was 0.74 diopters (D) in the intervention group and 0.78 D in the control group; the difference between groups was not statistically significant (P>.5, unpaired 2-tailed Student t test). The variance in SIA was 0.29 D(2) and 0.31 D(2), respectively; the difference between groups was not statistically significant (P>.5, unpaired F test). CONCLUSIONS: Attempts to correct for posture-related ocular cyclotorsion did not influence SIA or its variance in a single-surgeon series. These results should be interpreted with full appreciation of the limitations of currently available techniques to correct for posture-related ocular cyclotorsion in the clinical setting.
    • Uncorrected visual acuity in the immediate postoperative period following uncomplicated cataract surgery: bimanual microincision cataract surgery versus standard coaxial phacoemulsification.

      Saeed, Ayman; O'Connor, Jeremy; Cunnife, Geraldine; Stack, Jim; Mullhern, Mark G; Beatty, Stephen; Waterford Regional Hospital, Waterford, Ireland. aymantalat@gmail.com (2012-02-01)
      AIM: We compared bimanual microincision cataract surgery (MICS) and standard coaxial phacoemulsification (CAP) in terms of uncorrected visual acuity (UCVA) recorded 1 h and 2 weeks postoperatively. METHODS: This was a prospective, nonrandomised comparative study. All MICS procedures were performed by one surgeon (MGM), and all CAP procedures were performed by another surgeon (SB). Eyes with visually consequential ocular morbidity were excluded. The primary outcome measure was UCVA recorded 1 h postoperatively. RESULTS: One hundred eyes underwent MICS and CAP (50 eyes in each group). The treatment groups did not differ significantly in terms of preoperative mean best corrected visual acuity (6/24 +/- 4.3 lines and 6/20 +/- 4.4 lines in the MICS and the CAP groups, respectively; P = 0.65). Also, there was no significant difference in terms of postoperative UCVA at 1 h or at 2 weeks (mean +/- standard deviation UCVA 1 h postoperatively: MICS: 6/36 +/- 5.7 lines; CAP: 6/30 +/- 4.7 lines; P = 0.80; UCVA 2 weeks postoperatively: MICS: 6/10 +/- 1.9 lines; CAP: 6/10 +/- 2.2 lines; P = 0.90). However, nine eyes (18%) and one eye (2%) achieved a UCVA of C6/12 at 1 h following MICS and CAP, respectively, and this difference was statistically significant (P = 0.02). CONCLUSION: Mean UCVA at 1 h and at 2 weeks following cataract surgery was not significantly different between eyes undergoing MICS and CAP. However, a greater proportion of patients achieved a UCVA of C6/12 following MICS when compared with CAP.
    • Value of dual biometry in the detection and investigation of error in the preoperative prediction of refractive status following cataract surgery.

      Charalampidou, Sofia; Dooley, Ian; Molloy, Laura; Beatty, Stephen; Department of Ophthalmology, Waterford Regional Hospital, Waterford, Ireland., sonia.sofia1@gmail.com (2012-02-01)
      PURPOSE: To report the value of dual biometry in the detection of biometry errors. METHODS: Study 1: retrospective study of 224 consecutive cataract operations. The intraocular lens power calculation was based on immersion biometry. Study 2: immersion biometry was compared with optical coherence biometry (OCB) in terms of axial length, anterior chamber depth, keratometry readings and the recommended lens power to achieve emmetropia. Study 3: prospective study of 61 consecutive cataract operations. Both immersion and OCB were performed, but lens power calculation was based on the latter. RESULTS: Study 1: 115 (86%), 101 (75.4%), 90 (67.2%) and 50 (37.3%) of postoperative spherical equivalents were within +/-1.5 dioptres (D), +/-1.25 D, +/-1 D and +/-0.5 D of the target, respectively. Study 2: excellent agreement between axial length readings, anterior chamber depth readings and keratometry readings by immersion biometry and OCB was observed (reflected in a mean bias of -0.065 mm, -0.048 mm and +0.1803 D, respectively, in association with OCB). Agreement between the lens power recommended by each technique to achieve emmetropia was poor (mean bias of +1.16 D in association with OCB), but improved following appropriate modification of lens constants in the Accutome A-scan software (mean bias with OCB = -0.4 D). Study 3: 37 (92.5%) and 23 (57.5%) of operated eyes achieved a postoperative refraction within +/-1 D and +/-0.5 D of target, respectively. CONCLUSION: Systematic errors in biometry can exist, in the presence of acceptable postoperative refractive results. Dual biometry allows each biometric parameter to be scrutinized in isolation, and identify sources of error that may otherwise go undetected.