Visual performance in a flight simulator: multifocal intraocular lenses in pilots.

OBJECTIVE: To compare the performance of adults with multifocal intraocular lenses (MIOLs) in a realistic flight simulator with age-matched adults with monofocal intraocular lenses (IOLs). METHODS AND ANALYSIS: Twenty-five adults ≥60 years with either bilateral MIOL or bilateral IOL implantation were enrolled. Visual function tests included visual acuity and contrast sensitivity under photopic and mesopic conditions, defocus curves and low luminance contrast sensitivity tests in the presence and absence of glare (Mesotest II), as well as halo size measurement using an app-based halometer (Aston halometer). Flight simulator performance was assessed in a fixed-based flight simulator (PS4.5). Subjects completed three simulated landing runs in both daytime and night-time conditions in a randomised order, including a series of visual tasks critical for safety. RESULTS: Of the 25 age-matched enrolled subjects, 13 had bilateral MIOLs and 12 had bilateral IOLs. Photopic and mesopic visual acuity or contrast sensitivity were not significantly different between the groups. Larger halo areas were seen in the MIOL group and Mesotest values were significantly worse in the MIOL group, both with and without glare. The defocus curves showed better uncorrected visual acuity at intermediate and near distances for the MIOL group. There were no significant differences regarding performance of the vision-related flight simulator tasks between both groups. CONCLUSIONS: The performance of visually related flight simulator tasks was not significantly impaired in older adults with MIOLs compared with age-matched adults with monofocal IOLs. These findings suggest that MIOLs do not impair visual performance in a flight simulator.

Standardised antibacterial Manuka honey in the management of persistent post-operative corneal oedema: a case series.

BACKGROUND: Corneal oedema is a common post-operative problem that delays or prevents visual recovery from ocular surgery. Honey is a supersaturated solution of sugars with an acidic pH, high osmolarity and low water content. These characteristics inhibit the growth of micro-organisms, reduce oedema and promote epithelialisation. This clinical case series describes the use of a regulatory approved Leptospermum species honey ophthalmic product, in the management of post-operative corneal oedema and bullous keratopathy. METHODS: A retrospective review of 18 consecutive cases (30 eyes) with corneal oedema persisting beyond one month after single or multiple ocular surgical procedures (phacoemulsification cataract surgery and additional procedures) treated with Optimel Antibacterial Manuka Eye Drops twice to three times daily as an adjunctive therapy to conventional topical management with corticosteroid, aqueous suppressants, hypertonic sodium chloride five per cent, eyelid hygiene and artificial tears. Visual acuity and central corneal thickness were measured before and at the conclusion of Optimel treatment. RESULTS: A temporary reduction in corneal epithelial oedema lasting up to several hours was observed after the initial Optimel instillation and was associated with a reduction in central corneal thickness, resolution of epithelial microcysts, collapse of epithelial bullae, improved corneal clarity, improved visualisation of the intraocular structures and improved visual acuity. Additionally, with chronic use, reduction in punctate epitheliopathy, reduction in central corneal thickness and improvement in visual acuity were achieved. Temporary stinging after Optimel instillation was experienced. No adverse infectious or inflammatory events occurred during treatment with Optimel. CONCLUSIONS: Optimel was a safe and effective adjunctive therapeutic strategy in the management of persistent post-operative corneal oedema and warrants further investigation in clinical trials.

Late reactivation of herpes zoster keratitis results in band keratopathy.

PURPOSE: To report an unusual case of a late-stage reactivation of immune stromal keratitis associated with herpes zoster ophthalmicus (HZO), occurring without any apparent predisposing factors, more than 4 years after an acute zoster dermatomal rash. Significant corneal hypoesthesia and a central band keratopathy developed within 6 months of the late-stage reactivation. The clinical case management, issues associated with management, and management options are discussed, including the use of standardized, regulatory approved, antibacterial medical honey. CASE REPORT: An 83-year-old woman presented for routine review with a reactivation of right anterior stromal keratitis and mild anterior uveitis, occurring more than 4 years after an acute HZO dermatomal rash and an associated initial episode of anterior stromal keratitis. Corneal sensation became markedly impaired, and over the subsequent 6 months, a right central band keratopathy developed despite oral antiviral and topical steroid therapy. Visual acuity with pinhole was reduced to 20/100 in the affected eye and moderate irritation and epiphora were experienced. The patient declined the surgical intervention options of chelation, lamellar keratectomy, and phototherapeutic keratectomy to treat the band keratopathy. Longer-term management has involved preservative-free artificial tears, eyelid hygiene, standardized antibacterial medical honey, topical nonpreserved steroid, and UV-protective wraparound sunglasses. The clinical condition has improved over 14 months with this ocular surface management regimen, and visual acuity of 20/30 is currently achieved in a comfortable eye. CONCLUSIONS: The chronic and recurrent nature of HZO can be associated with significant corneal morbidity, even many years after the initial zoster episode. Long-term review and management of patients with a history of herpes zoster stromal keratitis are indicated following the initial corneal involvement. Standardized antibacterial medical honey can be considered in the management of the chronic ocular surface disease associated with HZO and warrants further evaluation in clinical trials.

Effect of antibacterial honey on the ocular flora in tear deficiency and meibomian gland disease.

PURPOSE: To assess for differences in the ocular flora of patients with dry eye caused by tear deficiency and/or meibomian gland disease and to assess the effect of antibacterial honey on the ocular flora in these forms of dry eye. METHODS: In this prospective, open-label pilot study, bacteria isolated from the eyelid margin and conjunctiva were identified and quantified before and at 1 and 3 months after initiation of treatment with topical application of antibacterial honey 3 times daily. Subjects had non-Sjogren tear deficiency (n = 20), Sjogren syndrome tear deficiency (n = 11), meibomian gland disease (n = 15), and non-Sjogren tear deficiency with meibomian gland disease (n = 20), and there were 18 non-dry eye subjects. RESULTS: The total colony-forming units (CFUs) isolated from each of the dry eye subgroups before antibacterial honey use was significantly greater than the total CFU isolated from the non-dry eye group. Antibacterial honey use significantly reduced total CFUs for the eyelids and the conjunctiva of dry eye subjects from baseline at month 1 (eyelids: P = 0.0177, conjunctiva: P = 0.0022) and month 3 (eyelids: P < 0.0001, conjunctiva: P < 0.0001). At month 3, there were reductions in total CFUs for all dry eye subgroups such that the CFUs were not significantly different from those of the non-dry eye group. CONCLUSION: From these results, there is sufficient preliminary data to warrant further study of the effects of antibacterial honey in chronic ocular surface diseases.

Dry eye after LASIK: comparison of outcomes for Asian and Caucasian eyes.

BACKGROUND: Dry eye is a common complication of LASIK surgery. Our clinical impression was that post-LASIK dry eye was more problematic for our Asian patients. The aim of this study was to determine if dry eye after LASIK is more prevalent, more sustained and more severe in Asian eyes compared with Caucasian eyes. METHODS: This study was based on a retrospective analysis of a clinical database. Data (n = 932 eyes, 932 patients) was collected before and after (week 2 and months 1, 3 and 6) LASIK surgery. Patients were defined as Asian if both parents were of East Asian ethic origin. Assessments included dry eye symptoms, ocular surface staining, tear volume, tear secretion, tear film stability and corneal sensation. RESULTS: Asian eyes had greater ocular surface staining, poorer tear film stability and lower tear volume before LASIK and at all times after LASIK. Dry eye symptoms occurring 'often or constantly' were more prevalent at all time points after LASIK in Asian eyes. Chronic dry eye persisting six months or more after LASIK was diagnosed in 28 per cent of Asian eyes and 5 per cent of Caucasian eyes (p < 0.001). Asian patients with chronic dry eye were predominantly female, reported dry eye symptoms, had greater ocular surface staining and lower tear secretion, stability and volume before surgery. After LASIK, Asian eyes had a slower return to pre-operative values for ocular surface staining, tear volume and corneal sensation. DISCUSSION: The risk of chronic dry eye after LASIK was significantly higher in Asian eyes. Contributing factors could include racial differences in eyelid and orbital anatomy, tear film parameters and blinking dynamics and higher attempted refractive corrections in Asian eyes.

Wavefront aberrations following laser in situ keratomileusis and refractive lens exchange for hypermetropia.

PURPOSE: To compare the magnitude of aberrations in eyes after elective hypermetropic laser in situ keratomileusis (LASIK) and refractive lens exchange (clear lens replacement). METHODS: Forty-nine patients (92 eyes) had hypermetropic LASIK and 28 (48 eyes) had refractive lens exchange; 23 hypermetropic subjects (41 eyes) were the control group. LASIK was performed with the Nidek EC-5000 excimer laser; ablation zones 5.5 to 6.0-mm in diameter with transition zones 7.5 to 8-mm in diameter. For refractive lens exchange, all but four IOLs were made of foldable acrylic. Aberrations and corneal topography were measured with the Nidek OPD-Scan model ARK-10000 more than 12 months after surgery. The higher-order root-mean-square (HORMS) wave aberrations for combined third to sixth Zernike aberration orders and the Zernike spherical aberration coefficient C(0)(4) at both 4.2-mm and 6.0-mm pupil sizes were calculated. RESULTS: For the LASIK group, surgical refractive change correlated significantly with total, corneal, and internal HORMS and spherical aberrations (except with internal spherical aberration for a 4.2-mm diameter pupil). For the refractive lens exchange group, there were no significant correlations of surgical refractive change with any of these factors. Similarly, there were no significant correlations of refraction with any of these factors for the control group. For a 3-diopter change in refraction with 6-mm pupils, LASIK doubled the total HORMS aberrations. LASIK changed the sign of spherical aberration from positive to negative by increasing the negative asphericity of the anterior cornea. Taking age differences between groups into account, refractive lens exchange increased the total HORMS aberrations by 40% compared with that of the control group, but this was not statistically significant. However, refractive lens exchange significantly increased total spherical aberration. CONCLUSION: Refractive lens exchange was a better refractive procedure than LASIK for minimizing total higher order optical aberrations that accompany hypermetropic refractive surgery.

Chronic dry eye and regression after laser in situ keratomileusis for myopia.

PURPOSE: To examine the relationship between chronic dry eye and refractive regression after laser in situ keratomileusis (LASIK) for myopia. SETTING: Excimer Laser Vision Centre and Centre for Eye Research, Queensland University of Technology, Brisbane, Australia. METHODS: This study was based on a retrospective analysis of a clinical database and a case study series. Data (N = 565 eyes) were collected before and after (2 weeks and 1, 3, 6, and 12 months) LASIK. Three case studies, which highlight appropriate management strategies for LASIK candidates with dry eye, are presented. RESULTS: Regression after LASIK was related to chronic dry eye. It occurred in 12 (27%) of 45 patients with chronic dry eye and in 34 (7%) of 520 patients without (P<.0001). Patients with chronic dry eye had significantly worse myopic outcomes than those without (1 month, P =.02; 3 months, P =.01; 6 months, P =.004; 12 months, P =.008). The risk for chronic dry eye was significantly associated with female sex, higher attempted refractive correction, greater ablation depth, and the following pre-LASIK variables: increased ocular surface staining; lower tear volume, tear stability, and corneal sensation; and dry-eye symptoms before LASIK. The risk for regression was significantly associated with higher attempted refractive correction, greater ablation depth, and dry-eye symptoms after LASIK. Case studies demonstrated that intensive dry-eye treatment may improve the refractive outcome and alleviate the need for enhancement surgery. CONCLUSION: The risk for refractive regression after LASIK was increased in patients with chronic dry eye.

Management of the ocular surface and tear film before, during, and after laser in situ keratomileusis.

PURPOSE: To identify evidence-based, best practice strategies for managing the ocular surface and tear film before, during, and after laser in situ keratomileusis (LASIK). METHODS: After a comprehensive review of relevant published literature, evidence-based recommendations for best practice management strategies are presented. RESULTS: Symptoms of ocular irritation and signs of dysfunction of the integrated lacrimal gland/ocular surface functional gland unit are common before and after LASIK. The status of the ocular surface and tear film before LASIK can impact surgical outcomes in terms of potential complications during and after surgery, refractive outcome, optical quality, patient satisfaction, and the severity and duration of dry eye after LASIK. Before LASIK, the health of the ocular surface should be optimized and patients selected appropriately. Dry eye before surgery and female gender are risk factors for developing chronic dry eye after LASIK. Management of the ocular surface during LASIK can minimize ocular surface damage and the risk of adverse outcomes. Long-term management of the tear film and ocular surface after LASIK can reduce the severity and duration of dry eye symptoms and signs. CONCLUSIONS: Strategies to manage the integrated ocular surface/lacrimal gland functional unit before, during, and after LASIK can optimize outcomes. As problems with the ocular surface and tear film are relatively common, attention should focus on the use and improvement of evidence-based management strategies.

Optical coherence tomography of adult-onset fovemacular vitelliform dystrophy.

Adult-onset foveomacular vitelliform dystrophy is characterized by a focal, round or oval shaped, subretinal foveal yellow lesion that presents bilaterally and usually symmetrically in the fourth or fifth decade of life. In addition to clinical observation, diagnosis of the disease process has until now been assisted by electrophysiological and fundus fluorescein studies. Two cases are presented that correlate the clinical fundus appearance with optical coherence tomography findings and describe the location of the yellow vitelliform material.

Ocular surface management of photorefractive keratectomy and laser in situ keratomileusis.

PURPOSE: To examine the effects of keratorefractive surgery and ocular surface management on goblet cell density, dry eye symptom incidence, and spherical equivalent refraction. METHODS: We performed a retrospective analysis of four myopia groups: Untreated controls (n = 53); PRK (n = 51); LASIK without ocular surface management (n = 56); LASIK with ocular surface management (n = 140). Ocular surface management involved the routine use of non-preserved artificial tears and other lubricants before, during, and after surgery. Lid hygiene procedures, topical anti-inflammatory agents, and punctal plugs were used on indication. Assessments were conducted before and up to 12 months after surgery (right eyes only in patients with both eyes operated, and in the left or right eye in patients with one eye operated). RESULTS: Surgery caused a significant reduction in goblet cell density, with the greatest reduction in the LASIK without ocular surface management group. No significant differences were detected in dry eye symptoms or spherical equivalent refraction between PRK and LASIK without ocular surface management. Ocular surface management significantly minimized LASIK-induced decreases in goblet cell density and was associated with significantly less myopic outcomes at months 1 to 3 and 6 to 9 after LASIK. After surgery (1 to 3 mo), dry eye symptoms were significantly lower in the LASIK with ocular surface management group. In all groups, significant inverse correlations existed between goblet cell density and dry eye symptoms. CONCLUSIONS: Ocular surface management minimized the negative impact of LASIK on goblet cell density and reduced dry eye symptoms. Without ocular surface management, goblet cell density and dry eye symptoms after LASIK were similar to or worse than after PRK.

Management of filamentary keratitis associated with aqueous-deficient dry eye.

PURPOSE: To review the incidence, underlying pathophysiology, and clinical features of filamentary keratitis and to identify evidence-based best-practice strategies for managing filamentary keratitis. METHODS: A comprehensive review of published literature was undertaken. Recommendations for best-practice management strategies were based on the available evidence. Three cases are presented to illustrate the clinical findings and management of patients with chronic filamentary keratitis. RESULTS: Although the evidence base is limited by the absence of well-designed studies, current evidence indicates the following: (1) Aqueous-deficient dry eye (keratoconjunctivitis sicca) is the most common ocular condition associated with filamentary keratitis. (2) Current best-practice management of filamentary keratitis involves treating the underlying dry eye and specific treatments for the corneal filaments. Proposed treatments include nonpreserved lubricants, topical steroidal and nonsteroidal anti-inflammatory agents, and punctal plugs for aqueous-deficient dry eye as well as mechanical removal of filaments, hypertonic saline, mucolytic agents, and bandage contact lenses for the filaments. (3) Filamentary keratitis can be induced or exacerbated by contact lens wear and ocular surgical procedures such as cataract surgery and corneal graft surgery. Pre- and postoperative ocular surface management strategies should be considered in the surgical planning of patients with, or who are susceptible to, filamentary keratitis. Filamentary keratitis can also be induced and/or exacerbated by chronic use of ocular and/or systemic medications, and alternate medications or additional measures to manage the tear film and ocular surface may be required in these cases. CONCLUSIONS: Filamentary keratitis can be a chronic, recurrent, and debilitating condition. With a systemic approach to diagnosis and management, the condition can be effectively controlled and the incidence and severity of recurrences minimized.

A comparison of the effect of refresh plus and bion tears on dry eye symptoms and ocular surface health in myopic LASIK patients.

PURPOSE: To compare the effect of artificial tears (0.5% carboxymethylcellulose [CMC] in lactate buffer vs. 0.3% hydroxypropyl methylcellulose and 0.1% dextran in bicarbonate buffer [HPMC]) on the preservation of ocular surface health in postoperative laser in situ keratomileusis (LASIK) patients. METHODS: Nonrandomized, comparative, retrospective analysis of a clinical database. Patients (n = 519; 985 eyes) had undergone LASIK in a single refractive surgery center performed by a single surgeon using the same LASIK technique (Nidek EC5000 laser and ACS keratome). Patients (n = 254) were given CMC (Refresh Plus/Cellufresh) or HPMC (Bion Tears) four times per day and were evaluated at presurgery, week 2, and months 1, 3, and 6. Included patients were those with complete clinical data through the month I follow-up visit. RESULTS: There were no significant between-group differences in any baseline variable. Following LASIK, fewer CMC patients (n = 111) reported dry eye symptoms than HPMC patients (n = 143) at the week 2 (13.5% vs. 30.8%; P = .001) and month 1 (19.8% vs. 38.5%; P = .001) follow-up visits. CMC patients also had significantly lower mean ocular surface staining scores than HPMC patients at week 2 (0.09 vs. 0.30; P = .015) and month 1 (0.05 vs. 0.28; P = .008). There were no between-group differences in either measure at months 3 or 6 (P < or = .728). CONCLUSIONS: CMC was more effective than HPMC in controlling dry eye symptoms and preserving ocular surface health in the immediate postoperative period in myopic post-LASIK patients, possibly due to the greater muco-adhesive properties of CMC. These results warrant further investigation as to the most effective postoperative LASIK lubricant.

Effect of laser in situ keratomileusis for hyperopia on tear film and ocular surface.

PURPOSE: To examine the effects of laser in situ keratomileusis (LASIK) for hyperopia on the tear film and ocular surface. METHODS: A retrospective 12-month analysis of 88 eyes (88 participants) who had LASIK for hyperopia was performed. Participants were evaluated before and after (2 weeks, 1, 3, 6, and 12 months) surgery for dry eye symptoms (McMonnies Dry Eye Survey primary symptoms), tear film stability (fluorescein break-up time), tear volume (phenol red thread test), ocular surface staining (fluorescein), and conjunctival goblet cell density. RESULTS: Chronic dry eye was experienced by 32% of participants; symptoms were significantly associated with female gender, preoperative dry eye symptoms, lower tear film stability after surgery, greater ocular surface staining after surgery, lower tear volume before and after surgery, and lower goblet cell densities after surgery. Regression rate 12 months after surgery was 32% and significantly associated with female gender, chronic dry eye symptoms, lower tear film stability after surgery, greater ocular surface staining before and after surgery, and lower tear volume before and after surgery. CONCLUSIONS: Dry eye, particularly in females, is problematic after LASIK for hyperopia and is associated with refractive regression. Current methods for managing the tear film and ocular surface may not control LASIK-induced dry eye, particularly in some females during the first 6 months after surgery.