BCLA CLEAR Presbyopia: Management with corneal techniques.

Corneal techniques for enhancing near and intermediate vision to correct presbyopia include surgical and contact lens treatment modalities. Broad approaches used independently or in combination include correcting one eye for distant and the other for near or intermediate vision, (termed monovision or mini-monovision depending on the degree of anisometropia) and/or extending the eye's depth of focus [1]. This report provides an overview of the evidence for the treatment profile, safety, and efficacy of the range of corneal techniques currently available for managing presbyopia. The visual needs and expectations of the patient, their ocular characteristics, and prior history of surgery are critical considerations for patient selection and preoperative evaluation. Contraindications to refractive surgery include unstable refraction, corneal abnormalities, inadequate corneal thickness for the proposed ablation depth, ocular and systemic co-morbidities, uncontrolled mental health issues and unrealistic patient expectations. Laser refractive options for monovision include surface/stromal ablation techniques and keratorefractive lenticule extraction. Alteration of spherical aberration and multifocal ablation profiles are the primary means for increasing ocular depth of focus, using surface and non-surface laser refractive techniques. Corneal inlays use either small aperture optics to increase depth of field or modify the anterior corneal curvature to induce corneal multifocality. Presbyopia correction by conductive keratoplasty involves application of radiofrequency energy to the mid-peripheral corneal stroma which leads to mid-peripheral corneal shrinkage, inducing central corneal steepening. Hyperopic orthokeratology lens fitting can induce spherical aberration and correct some level of presbyopia. Postoperative management, and consideration of potential complications, varies according to technique applied and the time to restore corneal stability, but a minimum of 3 months of follow-up is recommended after corneal refractive procedures. Ongoing follow-up is important in orthokeratology and longer-term follow-up may be required in the event of late complications following corneal inlay surgery.

Recommendation for Presbyopia-Correcting Intraocular Lenses: A Delphi Consensus Statement by the ESASO Study Group.

PURPOSE: To establish consensus among experts in lens and refractive surgery to guide general ophthalmologists on issues related to presbyopia-correcting intraocular lenses (IOLs). DESIGN: A modified Delphi method to reach a consensus among experts. METHODS: A steering committee formulated 105 relevant items grouped into four sections (preoperative considerations, IOL selection, intraoperative considerations, and postoperative considerations). The consensus was defined as ≥ 70% of experts agreeing with the evaluation of a statement. RESULTS: Ten experts participated and completed all rounds of questionnaires (100% response rate). Of 68 items considered in the preoperative considerations, consensus was achieved in 48 (70.6%). There was a lack of consensus over IOL selection, the experts only agreed on the importance of the patient's habits for the optical IOL design selection. Of the 14 considerations related to intraoperative issues, the experts reached a consensus on 10 (71.4%). The postoperative considerations section reached the highest consensus in 10 items of 13 (76.9%). CONCLUSIONS: Key recommendations for a diffractive multifocal IOL were a potential postoperative visual acuity > 0.5, a keratometry between 40-45 diopters, a pupil >2.8 mm under photopic conditions and <6.0 mm under scotopic conditions, a root mean square of higher order corneal aberrations <0.5 µm for 6-mm pupil size, while monofocal or non-diffractive IOLs should be considered for patients with coexisting eye disorders. A lack of agreement was found in the issues related to the IOL selection.

LASIK for the Correction of High Hyperopic Astigmatism With Epithelial Thickness Monitoring.

PURPOSE: To evaluate outcomes of high hyperopic LASIK using the MEL 80 excimer laser (Carl Zeiss Meditec, Jena, Germany). METHODS: Retrospective analysis of 830 consecutive high hyperopic LASIK procedures using the MEL 80 excimer laser and either the VisuMax femtosecond laser (Carl Zeiss Meditec) or zero compression Hansatome microkeratome (Bausch & Lomb, Rochester, NY). Inclusion criteria were attempted hyperopic correction of +4.00 diopters [D] or higher in one axis and corrected distance visual acuity (CDVA) of 20/20 or better. Patients were observed for a minimum of 1 year. Epithelial thickness monitoring by Artemis very high-frequency (VHF) digital ultrasound (ArcScan Inc., Morrison, CO) was used to evaluate potential for further steepening as a re-treatment. RESULTS: One-year data were available for 785 eyes. Mean attempted spherical equivalent refraction (SEQ) was +4.52 ± 0.84 D (range: +2.00 to +6.96 D) for the primary treatment and mean cylinder was 1.05 ± 0.86 D (range: 0.00 to 5.25 D). Mean age was 50 ± 12 years (range: 18 to 70 years) and 61% were women. Postoperative SEQ was ±0.50 D in 50% and ±1.00 D in 77% of eyes after primary treatment. After re-treatment, 67% of eyes were within ±0.50 D and 89% were within ±1.00 D. Uncorrected distance visual acuity was 20/20 or better in 76% of eyes after final treatment. One line of CDVA was lost in 25% of eyes and two lines were lost in 0.4%. There was a clinically insignificant but statistically significant decrease (P < .05) in contrast sensitivity (CSV-1000) by less than 1 log unit at 3 and 6 cycles per degree (cpd) and by 1 log unit at 12 and 18 cpd. Diurnal fluctuation in refraction was identified in 2 eyes, proven by VHF digital ultrasound to be due to diurnal epithelial remodeling overnight and unrelated to maximum postoperative keratometry induced. CONCLUSIONS: LASIK for hyperopia by cumulative treatment of up to +8.33 D with the MEL 80 excimer laser was found to satisfy accepted criteria for safety, efficacy, and stability when applying specialized protocols, including epithelial monitoring. [J Refract Surg. 2017;33(5):314-321.].

Introduction of a Toric Intraocular Lens to a Non-Refractive Cataract Practice: Challenges and Outcomes.

AIM: To identify challenges inherent in introducing a toric intraocular lens (IOL) to a non-refractive cataract practice, and evaluate residual astigmatism achieved and its impact on patient satisfaction. METHODS: Following introduction of a toric IOL to a cataract practice with all procedures undertaken by a single, non-refractive, surgeon (SB), pre-operative, intra-operative and post-operative data was analysed. Attenuation of anticipated post-operative astigmatism was examined, and subjectively perceived visual functioning was assessed using validated questionnaires. RESULTS: Median difference vector (DV, the induced astigmatic change [by magnitude and axis] that would enable the initial surgery to achieve intended target) was 0.93D; median anticipated DV with a non-toric IOL was 2.38D. One eye exhibited 0.75D residual astigmatism, compared to 3.8D anticipated residual astigmatism with a non-toric IOL. 100% of respondents reported satisfaction of ≥ 6/10, with 37.84% of respondents entirely satisfied (10/10). 17 patients (38.63%) reported no symptoms of dysphotopsia (dysphoptosia score 0/10), only 3 respondents (6.8%) reported a clinically meaningful level of dysphotopsia (≥ 4/10). Mean post-operative NEI VF-11 score was 0.54 (+/-0.83; scale 0 - 4). CONCLUSION: Use of a toric IOL to manage astigmatism during cataract surgery results in less post-operative astigmatism than a non-toric IOL, resulting in avoidance of unacceptable post-operative astigmatism.

Potential Effects of Corneal Cross-Linking upon the Limbus.

Corneal cross-linking is nowadays the most used strategy for the treatment of keratoconus and recently it has been exploited for an increasing number of different corneal pathologies, from other ectatic disorders to keratitis. The safety of this technique has been widely assessed, but clinical complications still occur. The potential effects of cross-linking treatment upon the limbus are incompletely understood; it is important therefore to investigate the effect of UV exposure upon the limbal niche, particularly as UV is known to be mutagenic to cellular DNA and the limbus is where ocular surface tumors can develop. The risk of early induction of ocular surface cancer is undoubtedly rare and has to date not been published other than in one case after cross-linking. Nevertheless it is important to further assess, understand, and reduce where possible any potential risk. The aim of this review is to summarize all the reported cases of a pathological consequence for the limbal cells, possibly induced by cross-linking UV exposure, the studies done in vitro or ex vivo, the theoretical bases for the risks due to UV exposure, and which aspects of the clinical treatment may produce higher risk, along with what possible mechanisms could be utilized to protect the limbus and the delicate stem cells present within it.

Long-term Visual and Refractive Outcomes After LASIK for High Myopia and Astigmatism From -8.00 to -14.25 D.

PURPOSE: To evaluate outcomes of high myopic LASIK using the MEL 80 excimer laser (Carl Zeiss Meditec, Jena, Germany). METHODS: Retrospective analysis of 479 consecutive high myopic LASIK procedures (318 patients) using the MEL 80 excimer laser and VisuMax femtosecond laser (Carl Zeiss Meditec) in 77% of cases or zero compression Hansatome microkeratome (Bausch & Lomb, Rochester, NY) in 23% of cases. Inclusion criteria were preoperative spherical equivalent refraction (SEQ) of between -8.00 and -14.25 diopters (D) and corrected distance visual acuity (CDVA) of 20/20 or better. Patients were observed for a minimum of 1 year. Flap thickness was between 80 and 160 µm and optical zone was between 5.75 and 6.50 mm. Standard outcomes analysis was performed. RESULTS: Mean attempted SEQ was -9.39 ± 1.22 D (range: -8.00 to -14.18 D) and mean cylinder was -1.03 ± 0.84 D (range: 0.00 to -4.50 D). Mean age was 37 ± 9 years (range: 21 to 60 years) with 54% female patients. Postoperative SEQ was ±0.50 D in 55% and ±1.00 D in 83% of eyes after primary treatment. After re-treatment, 69% of eyes were within ±0.50 D and 95% were within ±1.00 D. UDVA was 20/20 or better in 89% of eyes after final treatment. One line of CDVA was lost in 3% of eyes and no eyes lost two or more lines. Statistically significant increases (P < .001) were measured in contrast sensitivity (CSV-1000) at 12 and 18 cycles per degree. CONCLUSIONS: The MEL 80 excimer laser was found to achieve high efficacy and safety for treatment of high myopia between -8.00 and -14.25 D and up to -4.50 D of cylinder. [J Refract Surg. 2016;32(5):290-297.].

Changes in ocular biomechanics after femtosecond laser creation of a laser in situ keratomileusis flap.

PURPOSE: To evaluate ocular biomechanical parameters with the Corvis ST, a noncontact tonometer combined with an ultra-high-speed Scheimpflug camera, before and after creation of a femtosecond laser-created laser in situ keratomileusis (LASIK) flap. SETTING: Private practice, Siena, Italy. DESIGN: Prospective consecutive study. METHODS: Right eyes of patients having LASIK were assessed with the dynamic Scheimpflug camera before and after femtosecond laser (LDV Z4) flap creation but before mechanical flap lifting. RESULTS: Twenty-eight eyes of 28 patients were evaluated. Before flap creation, the mean values on the dynamic Scheimpflug camera were intraocular pressure (IOP), 15.04 mm Hg ± 3.99 (SD); central pachymetry, 550.8 ± 101.0 µm; applanation 1 length, 1.721 ± 0.134 mm; applanation 2 length, 1.674 ± 0.287 mm; applanation 1 velocity, 0.126 ± 0.031 m/s; and deflection amplitude, 1.039 ± 0.141 mm. After flap creation, the mean values were IOP, 16.10 ± 3.11 mm Hg (95% confidence interval [CI], 0.44-1.78; P < .05); central pachymetry, 561.8 ± 35.9 µm (95% CI, -28.9 to 50.9; P = .21); applanation 1 length, 1.789 ± 0.1492 mm (95% CI, 0.003-0.134; P < .05); applanation 2 length, 1.759 ± 0.259 mm (95% CI, -0.005 to 0.173; P = .08); applanation 1 velocity, 0.136 ± 0.022 m/s (95% CI, 0.001-0.017; P < .05); and deflection amplitude, 1.029 ± 0.151 mm (95% CI: -0.043 to 0.025; P = .34). CONCLUSION: The dynamic Scheimpflug camera showed changes in biomechanical properties after femtosecond creation of a LASIK flap as indicated by an increased applanation 1 length and applanation 1 velocity. FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned.

Can the accuracy of multifocal intraocular lens power calculation be improved to make patients spectacle free?

PURPOSE: To optimise intraocular lens (IOL) power calculation techniques for a segmental multifocal IOL, LENTIS™ MPlus(®) (Oculentis GmbH, Berlin, Germany) and assess outcomes. METHODS: A retrospective consecutive non-randomised case series of patients receiving the MPlus(®) IOL following cataract surgery or clear lens extraction was performed at a privately owned ophthalmic hospital, Midland Eye, Solihull, UK. Analysis was undertaken of 116 eyes, with uncomplicated lens replacement surgery using the LENTIS™ MPlus(®) lenses. Pre-operative biometry data were stratified into short (<22.00 mm) and long axial lengths (ALs) (≥22.00 mm). IOL power predictions were calculated with SRK/T, Holladay I, Hoffer Q, Holladay II and Haigis formulae and compared to the final manifest refraction. These were compared with the OKULIX ray tracing method and the stratification technique suggested by the Royal College of Ophthalmologists (RCOphth). RESULTS: Using SRK/T for long eyes and Hoffer Q for short eyes, 64% achieved postoperative subjective refractions of ≤±0.25 D, 83%≤±0.50 D and 93%≤±0.75 D, with a maximum predictive error of 1.25D. No specific calculation method performed best across all ALs; however for ALs under 22 mm Hoffer Q and Holliday I methods performed best. CONCLUSIONS: Excellent but equivalent overall refractive results were found between all biometry methods used in this multifocal IOL study. For eyes with ALs under 22 mm Hoffer Q and Holliday I performed best. Current techniques mean that patients are still likely to need top up glasses for certain situations.

Keratin 12 missense mutation induces the unfolded protein response and apoptosis in Meesmann epithelial corneal dystrophy.

Meesmann epithelial corneal dystrophy (MECD) is a rare autosomal dominant disorder caused by dominant-negative mutations within the KRT3 or KRT12 genes, which encode the cytoskeletal protein keratins K3 and K12, respectively. To investigate the pathomechanism of this disease, we generated and phenotypically characterized a novel knock-in humanized mouse model carrying the severe, MECD-associated, K12-Leu132Pro mutation. Although no overt changes in corneal opacity were detected by slit-lamp examination, the corneas of homozygous mutant mice exhibited histological and ultrastructural epithelial cell fragility phenotypes. An altered keratin expression profile was observed in the cornea of mutant mice, confirmed by western blot, RNA-seq and quantitative real-time polymerase chain reaction. Mass spectrometry (MS) and immunohistochemistry demonstrated a similarly altered keratin profile in corneal tissue from a K12-Leu132Pro MECD patient. The K12-Leu132Pro mutation results in cytoplasmic keratin aggregates. RNA-seq analysis revealed increased chaperone gene expression, and apoptotic unfolded protein response (UPR) markers, CHOP and Caspase 12, were also increased in the MECD mice. Corneal epithelial cell apoptosis was increased 17-fold in the mutant cornea, compared with the wild-type (P < 0.001). This elevation of UPR marker expression was also observed in the human MECD cornea. This is the first reporting of a mouse model for MECD that recapitulates the human disease and is a valuable resource in understanding the pathomechanism of the disease. Although the most severe phenotype is observed in the homozygous mice, this model will still provide a test-bed for therapies not only for corneal dystrophies but also for other keratinopathies caused by similar mutations.

Protein Composition of TGFBI-R124C- and TGFBI-R555W-Associated Aggregates Suggests Multiple Mechanisms Leading to Lattice and Granular Corneal Dystrophy.

PURPOSE: Transforming growth factor beta-induced (TGFBI)-related dystrophies constitute the most common heritable forms of corneal dystrophy worldwide. However, other than the underlying genotypes of these conditions, a limited knowledge exists of the exact pathomechanisms of these disorders. This study expands on our previous research investigating dystrophic stromal aggregates, with the aim of better elucidating the pathomechanism of two conditions arising from the most common TGFBI mutations: granular corneal dystrophy type 1 (GCD1; R555W) and lattice corneal dystrophy type 1 (LCD1; R124C). METHODS: Patient corneas with GCD1 and LCD1 were stained with hematoxylin and eosin and Congo red to visualize stromal nonamyloid and amyloid deposits, respectively. Laser capture microdissection was used to isolate aggregates and extracted protein was analyzed by mass spectrometry. Proteins were identified and their approximate abundances were determined. Spectra of TGFBIp peptides were also recorded and quantified. RESULTS: In total, three proteins were found within GCD1 aggregates that were absent in the healthy control corneal tissue. In comparison, an additional 18 and 24 proteins within stromal LCD1 and Bowman's LCD1 deposits, respectively, were identified. Variances surrounding the endogenous cleavage sites of TGFBIp were also noted. An increase in the number of residues experiencing cleavage was observed in both GCD1 aggregates and LCD1 deposits. CONCLUSIONS: The study reveals previously unknown differences between the protein composition of GCD1 and LCD1 aggregates, and confirms the presence of the HtrA1 protease in LCD1-amyloid aggregates. In addition, we find mutation-specific differences in the processing of mutant TGFBIp species, which may contribute to the variable phenotypes noted in TGFBI-related dystrophies.

siRNA silencing of the mutant keratin 12 allele in corneal limbal epithelial cells grown from patients with Meesmann's epithelial corneal dystrophy.

PURPOSE: The aim of this study is to further assess our previously reported keratin 12 (K12)-Leu132Pro specific siRNA in silencing the mutant allele in Meesmann's Epithelial Corneal Dystrophy (MECD) in experimental systems more akin to the in vivo situation through simultaneous expression of both wild-type and mutant alleles. METHODS: Using KRT12 exogenous expression constructs transfected into cells, mutant allele specific knockdown was quantified using pyrosequencing and infrared Western blot analysis, while the silencing mechanism was assessed by a modified rapid amplification of cDNA ends (5'RACE) method. Corneal limbal biopsies taken from patients suffering from MECD were used to establish cultures of MECD corneal limbal epithelial stem cells and the ability of the siRNA to silence the endogenous mutant KRT12 allele was assessed by a combination of pyrosequencing, qPCR, ELISA, and quantitative-fluorescent immunohistochemistry (Q-FIHC). RESULTS: The siRNA displayed a potent and specific knockdown of K12-Leu132Pro at both the mRNA and protein levels with exogenous expression constructs. Analysis by the 5'RACE method confirmed siRNA-mediated cleavage. In the MECD cells, an allele-specific knockdown of 63% of the endogenous mutant allele was observed without effect on wild-type allele expression. CONCLUSIONS: Combined with an effective delivery vehicle this siRNA approach represents a viable treatment option for prevention of the MECD pathology observed in K12-Leu132Pro heterozygous individuals.

Development of allele-specific gene-silencing siRNAs for TGFBI Arg124Cys in lattice corneal dystrophy type I.

PURPOSE: This study aimed to investigate the potency and specificity of short-interfering RNA (siRNA) treatment for TGFBI-Arg124Cys lattice corneal dystrophy type I (LCDI) using exogenous expression constructs in model systems and endogenous gene targeting in an ex vivo model using corneal epithelial cell cultures. METHODS: A panel of 19 TGFBI-Arg124Cys-specific siRNAs were assessed by a dual-luciferase reporter assay. Further assessment using pyrosequencing and qPCR was used to identify the lead siRNA; suppression of mutant TGFBIp expression was confirmed by Western blot and Congo red aggregation assays. An ex vivo model of LCDI was established using limbal biopsies from corneal dystrophy patients harboring the Arg124Cys mutation. Treatment efficiency of the siRNA was assessed for the inhibition of the mutant allele in the primary patient's corneal epithelial cells using pyrosequencing, quantitative PCR (qPCR), and an ELISA. RESULTS: A lead siRNA was identified, and demonstrated to be potent and specific in inhibiting the TGFBI-Arg124Cys mutant allele at the mRNA and protein levels. Besides high allele specificity, siRNA treatment achieved a 44% reduction of the endogenous Arg124Cys allele in an ex vivo model of LCDI. CONCLUSIONS: We have identified a lead siRNA specific to the TGFBI-Arg124Cys mutant allele associated with LCDI. Silencing of exogenous TGFBI was observed at mRNA and protein levels, and in an ex vivo model of LCDI with an efficient suppression of the endogenous mutant allele. This result indicates the potential of siRNA treatment as a personalized medicine approach for the management of heritable TGFBI-associated corneal dystrophies.

Early flap displacement after LASIK.

PURPOSE: To evaluate the risks of flap displacement after LASIK. DESIGN: Retrospective case series. PARTICIPANTS: We included 41 845 consecutive adults who underwent LASIK surgery at Optical Express in the United Kingdom, including 81 238 eyes, of which 14 555 were hyperopic and 66 681 myopic or mixed astigmatic. We treated 57 241 eyes with the IntraLase FS-60 femtosecond laser and 23 997 with the Moria S.A. ONE Use-Plus automated microkeratome. METHODS: We calculated the incidence of all flap displacements in the study population during an observational time period of ≥12 months after surgery. Independent variables were entered into logistic regression models to identify risk factors. Postoperative outcomes were assessed. MAIN OUTCOME MEASURES: The incidence and odds ratios (OR) of flap displacement in the study population and in categories of refractive error and flap surgery technique. RESULTS: The incidence of flap displacements was 10 in 81 238 LASIK procedures (0.012%), including 8 hyperopic eyes (0.055%) and 2 myopic eyes (0.003%). All flap displacements occurred within 48 hours of surgery and none were preceded by ocular trauma. They were classified as "early flap displacements" (EFD). The incidence of EFD after microkeratome surgery was 0.033% (n = 8), and after femtosecond laser it was 0.003% (n = 2). In hyperopic eyes having microkeratome surgery, the incidence was 0.179% (n = 7). In a logistic regression model, the strongest predictor of EFD after LASIK was hyperopia, recording an OR of 19.29 (P<0.001). The OR of developing an EFD after microkeratomy was 10.53 times higher than after femtosecond laser (P<0.005). In hyperopes, the OR of an EFD was 18.87 times higher after microkeratomy than after femtosecond treatment. Four of 10 displaced flaps needed secondary surgery, and 1 eye lost 2 lines of best-corrected visual acuity. CONCLUSIONS: The incidence of flap displacements during a 12-month period after LASIK was extremely low (0.012%). Although the small number of displacements with the femtosecond laser limits conclusions, the risk of EFD was higher after microkeratome surgery than femtosecond laser.

Excimer laser surface ablation - a review.

Corneal surface laser ablation procedures for the correction of refractive error have enjoyed a resurgence of interest, especially in patients with a possible increased risk of complications after lamellar surgery. Improvements in the understanding of corneal biomechanical changes, the modulation of wound healing, laser technology including ablation profiles and different methods for epithelial removal have widened the scope for surface ablation. This article discusses photorefractive keratectomy, trans-epithelial photorefractive keratectomy, laser-assisted sub-epithelial keratomileusis and epithelial-laser-assisted in situ keratomileusis.

Documentation of corneal epithelial defects with fluorescein-enhanced digital fundus camera photography.

The advent of digital photography in the ophthalmic setting has provided not only a means of documenting pathology, but with instantaneous results, it is possible to aid clinical diagnosis and management. This study was designed to demonstrate the ability to image corneal epithelial lesions stained with fluorescein, with a digital fundus camera set on fluorescein angiography settings. The contrast of this technique demonstrated both gross and subtle corneal epithelial lesions better than traditional methods. The results obtained demonstrated the high sensitivity and high contrast images this technique can facilitate in every ophthalmic practice equipped with a fundus camera with digital fluorescein angiography capability.

Haze after photorefractive keratectomy caused by iatrogenic lagophthalmos.

A 22-year-old man had shortening of the levator muscle for a congenital blepharoptosis in the right eye in 2000. In September 2004, he was successfully treated by bilateral photorefractive keratectomy (PRK) for myopia and was asymptomatic with an uncorrected visual acuity of 20/20. In October 2005, right eye visual acuity decreased because of an inferiorly localized haze caused by nocturnal lagophthalmos. Fluorometholone eyedrops and lubrication induced full visual recovery after 2 months, but corresponding topographical abnormalities were only partially improved. Corneal exposure can induce haze after PRK, even in the long term. The efficacy of topical steroids indicates a role for inflammatory mediators in this condition. Eyelid position and dynamics must be evaluated before PRK to rule out lagophthalmos.

A cataract decision support system: its requirement is increasing.

Cataract surgery and intraocular lens implantation has taken on many significant advances since its earliest inception. As the prevalence of the aged population increases the number of cataract operations also increases year on year. In the UK last year over 300,000 cataract operations were performed with 2 million in Europe and 1.5 million in the USA. Globally 8.7 million cataract operations are performed per annum. Technical advances are occurring ever more rapidly in this procedure enabling improved preoperative assessment and surgical management. This has produced a sophisticated procedure which is eminently reproducible. In concordance with such improvements both patient and doctors expectations for visual results have also risen. The expectation is now that the operation will achieve more than mere removal of a pathological opacity interfering with the visual process. The possibility and expectation is that the procedure will be tailored specifically to the patient in such a way that the best possible visual result will be achieved through customization of the surgical process to optimize the individual's optical system. Optimization of any particular process may be complex, and cataract surgery is no exception. Careful consideration of many interrelated factors including a patient's functional visual requirements, along with specific anatomical and unique optical factors will be required if an optimum result is to be achieved. The decision making process involved in determining how an individual eye should be surgically customised, can therefore be complicated. These are the situations where decision support systems become most beneficial, to ensure consistent successful results, particularly if technical measurements are being performed by individuals with varying degrees of experience.