Intraoperative Aberrometry versus Preoperative Biometry for Intraocular Lens Power Calculations: A Report by the American Academy of Ophthalmology.

PURPOSE: To evaluate the published literature to compare intraoperative aberrometry (IA) with preoperative biometry-based formulas with respect to intraocular lens (IOL) power calculation accuracy for various clinical scenarios. METHODS: Literature searches in the PubMed database conducted in August 2022, July 2023, and February 2024 identified 157, 18, and 6 citations, respectively. These were reviewed in abstract form, and 61 articles were selected for full-text review. Of these, 29 met the criteria for inclusion in this assessment. The panel methodologists assigned a level of evidence rating to each of the articles; 4 were rated level I, 19 were rated level II, and 6 were rated level III. RESULTS: Intraoperative aberrometry performed better than traditional vergence formulas, including the Haigis, HofferQ, Holladay, and SRK/T, and similarly to the Barrett Universal II and Hill-RBF with respect to minimization of spherical equivalent (SE) refractive error. For toric IOLs, IA outperformed formulas that only considered anterior corneal astigmatism and was similar to formulas like the Barrett Toric Calculator (BTC), which empirically account for the contribution from the posterior cornea. In eyes with a history of corneal refractive surgery, IA performed similarly to the Barrett True-K and slightly better than other tested methods, including the Haigis-L, Shammas, and Wang-Koch-Maloney formulas. CONCLUSIONS: Intraoperative aberrometry corresponds well with modern vergence formulas, including the Barrett Universal II, Hill-RBF, BTC, and Barrett True-K. It has greater accuracy than traditional vergence-based IOL power calculation formulas in eyes with and without a history of corneal refractive surgery. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found after the references.

Toric Monofocal Intraocular Lenses for the Correction of Astigmatism during Cataract Surgery: A Report by the American Academy of Ophthalmology.

PURPOSE: To review the published literature evaluating the visual and refractive outcomes and rotational stability of eyes implanted with toric monofocal intraocular lenses (IOLs) for the correction of keratometric astigmatism during cataract surgery and to compare those outcomes with outcomes of eyes implanted with nontoric monofocal IOLs and other astigmatism management methods performed during cataract surgery. This assessment was restricted to the toric IOLs available in the United States. METHODS: A literature search of English-language publications in the PubMed database was last conducted in July 2022. The search identified 906 potentially relevant citations, and after review of the abstracts, 63 were selected for full-text review. Twenty-one studies ultimately were determined to be relevant to the assessment criteria and were selected for inclusion. The panel methodologist assigned each a level of evidence rating; 12 studies were rated level I and 9 studies were rated level II. RESULTS: Eyes implanted with toric IOLs showed excellent postoperative uncorrected distance visual acuity (UCDVA), reduction of postoperative refractive astigmatism, and good rotational stability. Uncorrected distance visual acuity was better and postoperative cylinder was lower with toric IOLs, regardless of manufacturer, when compared with nontoric monofocal IOLs. Correcting pre-existing astigmatism with toric IOLs was more effective and predictable than using corneal relaxing incisions (CRIs), especially in the presence of higher magnitudes of astigmatism. CONCLUSIONS: Toric monofocal IOLs are effective in neutralizing pre-existing corneal astigmatism at the time of cataract surgery and result in better UCDVA and significant reductions in postoperative refractive astigmatism compared with nontoric monofocal IOLs. Toric IOLs result in better astigmatic correction than CRIs, particularly at high magnitudes of astigmatism. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Novel heterozygous OPA3 variant in a family with congenital cataracts, sensorineural hearing loss and neuropathy, without optic atrophy and comparison of pathogenic and population variants.

Heterozygous mutations in the OPA3 gene are associated with autosomal dominant optic atrophy-3 (OPA3), whereas biallelic mutations cause autosomal recessive 3-methylglutaconic aciduria type III. To date, all cases with pathogenic variants in the gene OPA3 have presented with optic atrophy. We report a large family with congenital cataracts, hearing loss and neuropathy, with a likely pathogenic novel missense variant in OPA3, c.30G>C; p.(Lys10Asn) that segregates with disease in the family pedigree. The family's clinical presentation has significant phenotypic overlap with previously reported cases of OPA3, except for a notable lack of optic atrophy. The analysis of all known disease-associated variants in OPA3 revealed an enrichment in missense variants in patients with OPA3 phenotype compared with loss-of-function variants, which are more likely to be observed in individuals with 3-methylglutaconic aciduria type III, supporting different mechanisms of disease. This case broadens the clinical and genetic spectrum associated with OPA3 mutations and highlights that optic atrophy is not an obligate feature of OPA3-related disorders.

A survey of perceptions of exposure to new technology in residents and practicing ophthalmologists.

BACKGROUND: Incorporation of the rapid advances in ophthalmologic surgical and diagnostic techniques inherent in the field poses a challenge to residency training programs. This study investigates exposure to new technologies during residency and perception of its impact on practice patterns. METHODS: Ophthalmology residents at various training levels and practicing ophthalmologists who had completed their training were invited to participate in a survey study assessing exposure to various technologies in residency and in practice. Data collection occurred from December 2022 to June 2023. Descriptive statistics were performed. RESULTS: The study received 132 unique responses, including 63 ophthalmology residents and 69 practicing ophthalmologists. 65.2% (n = 45) of practicing ophthalmologists and 47.6% (n = 30) of current residents reported discussion/training on newly developed products on the market (e.g. premium IOLS, MIGS), was "minimally discussed but not emphasized" or "not discussed at all" in residency. 55.1% (n = 38) of practicing ophthalmologists reported that exposure to new technologies during residency did influence types of technologies employed during practice. The majority resident physicians reported enjoying being trained on newer technology and feeling more prepared for future changes in the field (95.2%, n = 60) and felt that having industry partnerships in residency enhances education and training (90.5%, n = 57). CONCLUSIONS: Considering how to maximize exposure to newer technologies/devices during residency training is important, and may contribute to training more confident, adaptable surgeons, who are more likely to critically consider new technologies and adopt promising ones into their future clinical practice.

Isolated Ocular Mpox without Skin Lesions, United States.

We report a case of a 53-year-old HIV-negative patient in San Francisco, California, USA, with no classic mpox prodromal symptoms or skin lesions who experienced fulminant, vision-threatening scleritis, keratitis, and uveitis. Deep sequence analysis identified monkeypox virus RNA in the aqueous humor. We confirmed the virus on the cornea and sclera by PCR.

Immediate Sequential Bilateral Surgery in Refractive Lens Exchange Patients: Clinical Outcomes and Adverse Events.

PURPOSE: To evaluate outcomes and the incidence of adverse events (AEs) in patients who underwent bilateral same-day refractive lens exchange (RLE). DESIGN: Retrospective case series. PARTICIPANTS: Patients of a private intraocular surgery provider in the United Kingdom who underwent RLE in both eyes on the same day with treatment dates between March 2018 and December 2021. METHODS: Clinical outcomes and AEs were collected for a continuous cohort of patients undergoing bilateral same-day RLE (in the absence of visually significant cataracts) or had mild cataracts (corrected visual acuity ≥ 20/40). One-month clinical outcomes were analyzed. MAIN OUTCOME MEASURES: Refractive outcomes and visual acuity, intraoperative and postoperative AEs, and secondary surgical interventions recorded within the first month after surgery. RESULTS: A total of 17 330 patients (34 660 eyes) were included in the analysis. Of these, 28 827 eyes received a multifocal intraocular lens (IOL), and 5833 eyes had a monofocal IOL. The percentage of eyes within ±0.50 diopters (D) of intended refraction was 85.5% and 86.2% for monofocal and multifocal IOL eyes, respectively. There was a total of 55 intraoperative AEs recorded in 55 eyes of 54 patients (per-eye incidence: 0.159%). Posterior capsule tear was the most common intraoperative event occurring in 37 eyes (0.107%). The number of AEs recorded within the first postoperative month was 267, occurring in 263 eyes of 177 patients (per-eye incidence: 0.759%). These included cystoid macular edema (CME) (172 eyes; 0.496%), significant corneal edema (28 eyes; 0.081%), persistent inflammation (27 eyes; 0.078%), significantly raised intraocular pressure (27 eyes; 0.078%), toxic anterior segment syndrome (8 eyes; 0.023%), wound leak (3 eyes; 0.009%), retinal detachment (1 eye; 0.003%), and retinal tear (1 eye; 0.003%). There were 56 secondary surgical interventions recorded within the first month of surgery, occurring in 54 eyes of 47 patients (per-eye incidence: 0.156%). The most common secondary intervention was the rotation of a misaligned toric IOL (24 eyes; 0.069%). CONCLUSIONS: Elective same-day bilateral RLE had a low incidence of serious AEs, and high refractive predictability. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Management of Pain after Photorefractive Keratectomy: A Report by the American Academy of Ophthalmology.

OBJECTIVE: To evaluate current best practices for postoperative photorefractive keratectomy (PRK) pain control. METHODS: Literature searches in the PubMed database were last conducted in October 2021 and were restricted to publications in English. This search identified 219 citations, of which 84 were reviewed in full text for their relevance to the scope of this assessment. Fifty-one articles met the criteria for inclusion; 16 studies were rated level I, 33 studies were rated level II, and 2 studies were rated level III. RESULTS: Systemic opioid and nonsteroidal anti-inflammatory drugs (NSAIDs); topical NSAIDs; postoperative cold patches; bandage soft contact lenses (BCLs), notably senofilcon A contact lenses; and topical anesthetics were demonstrated to offer significantly better pain control than comparison treatments. Some other commonly reported pain mitigation interventions such as systemic gabapentinoids, chilled intraoperative balanced salt solution (BSS) irrigation, cycloplegia, and specific surface ablation technique strategies offered limited improvement in pain control over control treatments. CONCLUSIONS: Systemic NSAIDs and opioid medications, topical NSAIDs, cold patches, BCLs, and topical anesthetics have been shown to provide improved pain control over alternative strategies and allow PRK-associated pain to be more tolerable for patients.

Femtosecond Laser-Assisted Cataract Surgery: A Report by the American Academy of Ophthalmology.

PURPOSE: To evaluate refractive outcomes, safety, and cost-effectiveness of femtosecond laser-assisted cataract surgery (FLACS) compared with phacoemulsification cataract surgery (PCS). METHODS: A PubMed search of FLACS was conducted in August 2020. A total of 727 abstracts were reviewed and 33 were selected for full-text review. Twelve articles met inclusion criteria and were included in this assessment. The panel methodologist assigned a level of evidence rating of I to all 12 studies. RESULTS: No significant differences were found in mean uncorrected distance visual acuity, best-corrected distance visual acuity, or the percentage of eyes within ± 0.5 and ± 1 diopter of intended refractive target between FLACS and PCS. Intraoperative and postoperative complication rates were similar between the 2 groups, and most studies showed no difference in endothelial cell loss between FLACS and PCS at various time points between 1 and 6 months. In large randomized controlled studies in the United Kingdom and France, FLACS was less cost-effective than PCS. CONCLUSIONS: Both FLACS and PCS have similar excellent safety and refractive outcomes. At this time, one technique is not superior to the other, but economic analyses performed in some populations have shown that FLACS is less cost-effective.

A Google Trends Approach to Identify Distinct Diurnal and Day-of-Week Web-Based Search Patterns Related to Conjunctivitis and Other Common Eye Conditions: Infodemiology Study.

BACKGROUND: Studies suggest diurnal patterns of occurrence of some eye conditions. Leveraging new information sources such as web-based search data to learn more about such patterns could improve the understanding of patients' eye-related conditions and well-being, better inform timing of clinical and remote eye care, and improve precision when targeting web-based public health campaigns toward underserved populations. OBJECTIVE: To investigate our hypothesis that the public is likely to consistently search about different ophthalmologic conditions at different hours of the day or days of week, we conducted an observational study using search data for terms related to ophthalmologic conditions such as conjunctivitis. We assessed whether search volumes reflected diurnal or day-of-week patterns and if those patterns were distinct from each other. METHODS: We designed a study to analyze and compare hourly search data for eye-related and control search terms, using time series regression models with trend and periodicity terms to remove outliers and then estimate diurnal effects. We planned a Google Trends setting, extracting data from 10 US states for the entire year of 2018. The exposure was internet search, and the participants were populations who searched through Google's search engine using our chosen study terms. Our main outcome measures included cyclical hourly and day-of-week web-based search patterns. For statistical analyses, we considered P<.001 to be statistically significant. RESULTS: Distinct diurnal (P<.001 for all search terms) and day-of-week search patterns for eye-related terms were observed but with differing peak time periods and cyclic strengths. Some diurnal patterns represented those reported from prior clinical studies. Of the eye-related terms, "pink eye" showed the largest diurnal amplitude-to-mean ratios. Stronger signal was restricted to and peaked in mornings, and amplitude was higher on weekdays. By contrast, "dry eyes" had a higher amplitude diurnal pattern on weekends, with stronger signal occurring over a broader evening-to-morning period and peaking in early morning. CONCLUSIONS: The frequency of web-based searches for various eye conditions can show cyclic patterns according to time of the day or week. Further studies to understand the reasons for these variations may help supplement the current clinical understanding of ophthalmologic symptom presentation and improve the timeliness of patient messaging and care interventions.

Impact of Refractive Outcomes on Bias in Follow-up and Completion of Patient-Reported Outcome Measures after Laser Vision Correction.

PURPOSE: To examine factors contributing to completion of a patient-reported outcome (PRO) measure in patients undergoing laser vision correction. DESIGN: Retrospective, population-based study. PARTICIPANTS: All patients who underwent primary laser vision correction with a target of plano from July 1, 2014, to June 30, 2016, at a large refractive surgery center. METHODS: Patients were asked to complete a PRO measure at the time of their preoperative and months 1 and 3 postoperative visits. Characteristics between patients who attended and did not attend the follow-up visits and completed and did not complete the PRO measure were compared. A logistic regression was performed to identify factors associated with likelihood of follow-up and completion of PRO measure. An inverse probability censoring weighted model was created to account for selective loss to follow-up and used to adjust the PRO satisfaction measure. MAIN OUTCOME MEASURE: Completion of the PRO measure at 1 and 3 months. RESULTS: A total of 37 043 patients were identified. Of these, 20 501 completed a 1-month postoperative PRO measure and 10 474 completed a 3-month postoperative PRO measure. Patients completing a PRO measure were more likely to be older, be female, have had photorefractive keratectomy (PRK), have completed a preoperative PRO measure, and have had a preoperative hyperopic correction (P < 0.001 for all comparisons). For every line of postoperative uncorrected acuity worse than 20/16, the odds ratio of completing a PRO measure was 1.33 (95% confidence interval [CI], 1.30-1.36, P < 0.001) at 1 month and 1.29 (95% CI, 1.26-1.33, P < 0.001) at 3 months. At 1 month, there was no difference between the raw and model-adjusted rates of satisfaction with vision, but at 3 months the adjusted rate was significantly higher than the raw rate. CONCLUSIONS: Patients with worse objective visual outcomes were more likely to complete PRO measures in this population-based study. In a setting with loss to follow-up, PRO measures require methods to address missing data for correct interpretation.

Intraocular Lens Power Calculation in Eyes with Previous Excimer Laser Surgery for Myopia: A Report by the American Academy of Ophthalmology.

PURPOSE: To review the literature to evaluate the outcomes of intraocular lens (IOL) power calculation in eyes with a history of myopic LASIK or photorefractive keratectomy (PRK). METHODS: Literature searches were conducted in the PubMed database in January 2020. Separate searches relevant to cataract surgery outcomes and corneal refractive surgery returned 1169 and 162 relevant citations, respectively, and the full text of 24 was reviewed. Eleven studies met the inclusion criteria for this assessment; all were assigned a level III rating of evidence by the panel methodologist. RESULTS: When automated keratometry was used with a theoretical formula designed for eyes without previous laser vision correction, the mean prediction error (MPE) was universally positive (hyperopic), the mean absolute errors (MAEs) and median absolute errors (MedAEs) were relatively high (0.72-1.9 diopters [D] and 0.65-1.73 D, respectively), and a low (8%-40%) proportion of eyes were within 0.5 D of target spherical equivalent (SE). Formulas developed specifically for this population requiring both prerefractive surgery keratometry and manifest refraction (i.e., clinical history, corneal bypass, and Feiz-Mannis) produced a proportion of eyes within 0.5 D of target SE between 26% and 44%. Formulas requiring only preoperative keratometry or no history at all had lower MAEs (0.42-0.94 D) and MedAEs (0.30-0.81 D) and higher (30%-68%) proportions within 0.5 D of target SE. Strategies that averaged several methods yielded the lowest reported MedAEs (0.31-0.35 D) and highest (66%-68%) proportions within 0.5 D of target SE. Even after using the best-known methods, refractive outcomes were less accurate in eyes that had previous excimer laser surgery for myopia compared with those that did not have it. CONCLUSIONS: Calculation methods requiring both prerefractive surgery keratometry and manifest refraction are no longer considered the gold standard. Refractive outcomes of cataract surgery in eyes that had previous excimer laser surgery are less accurate than in eyes that did not. Patients should be advised of this refractive limitation when considering cataract surgery in the setting of previous corneal refractive surgery. Conclusions are limited by the small sample sizes and retrospective nature of nearly all existing literature in this domain.

Multifocal and Accommodating Intraocular Lenses for the Treatment of Presbyopia: A Report by the American Academy of Ophthalmology.

PURPOSE: To review the published literature assessing the efficacy and safety of presbyopia-correcting intraocular lenses (IOLs) for the treatment of presbyopia after cataract removal. METHODS: Literature searches were undertaken in January 2018 and September 2020 in the PubMed, Medline, and Cochrane Library databases. This yielded 761 articles, of which 34 met the criteria for inclusion in this assessment and were assigned a level of evidence rating by the panel methodologist. Thirteen studies were rated level I and 21 studies were rated level II. RESULTS: Presbyopia-correcting lenses were effective at improving distance and near visual acuity after cataract surgery. Near acuity at different focal lengths was related directly to the effective add power of multifocal and extended depth-of-focus (EDOF) IOLs. Most multifocal and EDOF lenses that were compared with a control monofocal lens demonstrated that patient-reported spectacle independence was superior to the monofocal lens. All patients who had multifocal and EDOF lenses implanted showed decreased contrast sensitivity and reported more visual phenomena as compared with control participants who received monofocal lenses. CONCLUSIONS: Presbyopia-correcting lenses improve uncorrected near and distance visual acuity and decrease spectacle dependence after cataract surgery. Mesopic contrast sensitivity is decreased compared with monofocal lenses, and patient-reported visual phenomena are more likely in patients receiving multifocal or EDOF lenses.

Changes to ophthalmic clinical care during the coronavirus disease 2019 pandemic.

PURPOSE OF REVIEW: Given the impact that society as a whole, and medicine specifically, has experienced as a result of the COVID-19 pandemic, an examination of clinical care changes enacted in the field of ophthalmology is of interest to the specialty. RECENT FINDINGS: In order to adapt to the reality of the COVID-19 pandemic, measures, such as broadening telehealth capabilities, adopting universal masking, careful sanitation procedures, applying virtual teaching in academic environments, and deferring elective surgeries were put in place. These were aimed at reducing person-to-person spread of SARS-CoV-2. Though best efforts were made at triaging ophthalmic emergencies during these times, unfortunate delays in care were observed in some circumstances. Finally, a prospective study interrogating the risk of spread at slit lamp distances for short periods of time was encouraging, suggesting low risk of transmissibility, though limited by a small case-positive sample size. SUMMARY: Significant changes have been made in the design and delivery of ophthalmic care during the COVID-19 pandemic. Some of these, such as telemedicine, may provide value in a postpandemic world.

Refractive status during pregnancy in the United States: results from NHANES 2005-2008.

PURPOSE: Anecdotal reports of refractive changes in pregnancy are familiar to optometrists and ophthalmologists. Refractive stability during pregnancy has implications in both prescribing of refractive correction and candidacy for refractive surgery. This study aims to examine refractive status in a nationally representative sample of US pregnant women. METHODS: The National Health and Nutrition Examination Survey (NHANES) is a weighted, stratified, cross-sectional survey of the US population conducted every 2 years. During 2005-2006 and 2007-2008, the exam included multiple ophthalmic tests including refraction, keratometry, and lensometry. Female participants aged 20-44 years with available vision examination data were included in the study. Subjects were excluded if best obtainable visual acuity was worse than 20/40 or there was prior history of cataract or refractive surgery. The primary outcome was defined as refractive change stratified by trimester of pregnancy. RESULTS: 301 pregnant women were matched with 301 nonpregnant controls based on age, ethnicity, and education. There was no difference in refractive error between pregnant women and matched nonpregnant controls (all p > 0.99). For the refractive change analysis, a subgroup of 60 pregnant subjects with glasses at presentation was matched to 60 nonpregnant controls. Multivariate regression showed a significant increase in refractive change versus prior to glasses prescription by trimester of pregnancy (p = 0.02), though this change was not in a specific direction (i.e., no significant shift toward either myopia or hyperopia). CONCLUSIONS: Pregnant women have greater refractive difference from prior spectacle prescription later in pregnancy, but the direction of this change is variable and not significant. This finding may reflect a longer time to last glasses prescription later in pregnancy, given concerns that refractive error fluctuates in pregnancy. Additional longitudinal studies are needed to better characterize the effects of pregnancy on refractive status.

Military Teleconsultation Services Facilitate Prompt Recognition and Treatment of a Case of Syphilitic Uveitis Aboard a United States Navy Aircraft Carrier at Sea During Combat Operations Without Evacuation Capability.

Background: In the United States Armed Forces, telemedicine can bring specialist care into the field, augmenting the capabilities of health care providers in remote, austere environments to nearly the point of injury or illness. The early intervention enabled by telemedical consultation can not only guide crucial temporizing measures to safeguard life, limb, and eyesight, but can also facilitate care in resource limited environments, potentially avoiding need for patient evacuation. In circumstances when a higher level of care is needed, but unavailable or operationally not possible, telemedicine can guide management in the field until transport can be achieved. Methods: In the present case, a young male patient presented to medical company aboard a U.S. Navy aircraft carrier while deployed at sea for evaluation of an acute red eye. Despite initial therapeutic measures, his vision subsequently deteriorated. Uveitis was suspected, but transport off the ship to an eye care specialist was not possible during combat operations. Results: Telemedical consultation with shore-based ophthalmologists guided initial diagnostic and therapeutic efforts, resulting in the presumed diagnosis of syphilitic uveitis. With remote support of ophthalmology and infectious disease specialist care, the patient was treated at sea for this vision-threatening condition. As operational conditions allowed, the patient was later evacuated to definitive care. Conclusions: At follow up after treatment, the patient had an excellent visual outcome, and was promptly returned to duty.

Factors that influence intraocular pressure changes after myopic and hyperopic LASIK and photorefractive keratectomy: a large population study.

PURPOSE: To describe the factors that influence the measured intraocular pressure (IOP) change and to develop a predictive model after myopic and hyperopic LASIK and photorefractive keratectomy (PRK) in a large population. DESIGN: Retrospective, observational case series. PARTICIPANTS: Patients undergoing primary PRK or LASIK with a refractive target of emmetropia between January 1, 2008, and October 5, 2011. METHODS: The Optical Express database was queried for all subjects. Data were extracted on procedure specifics, preoperative central corneal thickness (CCT), IOP (using noncontact tonometry), manifest refraction, average keratometry, age, gender, and postoperative IOP at 1 week, 1 month, and 3 months. A linear mixed methods model was used for data analysis. MAIN OUTCOME MEASURES: Change in IOP from preoperatively to 1 month postoperatively. RESULTS: A total of 174 666 eyes of 91 204 patients were analyzed. Hyperopic corrections experienced a smaller IOP decrease than myopic corrections for both PRK and LASIK (P<0.0001). Patients who underwent LASIK had a 0.94 mmHg (95% confidence interval [CI], 0.89-0.98) greater IOP decrease than patients who underwent PRK (P<0.0001), reflecting the effect of the lamellar flap. The decrease in IOP was linearly related to preoperative manifest spherical equivalent (MSE) for myopic PRK and LASIK (P<0.0001), weakly correlated with preoperative MSE after hyperopic LASIK, and not related to preoperative MSE after hyperopic PRK. The single greatest predictor of IOP change was preoperative IOP across all corrections. By using the available data, a model was constructed to predict postoperative IOP change at 1 month; this was able to explain 42% of the IOP change after myopic LASIK, 34% of the change after myopic PRK, 25% of the change after hyperopic LASIK, and 16% of the change after hyperopic PRK. CONCLUSIONS: Myopic procedures lower measured IOP more than hyperopic procedures; this decrease was proportional to the amount of refractive error corrected. Independent of the refractive correction, the creation of the lamellar LASIK flap decreased measured IOP by 0.94 mmHg. A best-fit model for IOP change was developed that may allow better interpretation of post-laser vision correction IOP values.